HarmonyOS 鸿蒙Next头像裁剪圆形遮罩效果实现demo

【起因】
需要实现头像剪裁的圆形遮罩。
看到一个第三方库oh-crop是方形遮罩的
https://ohpm.openharmony.cn/#/cn/detail/@xinyansoft%2Foh-crop
【经过】
查看源码，修改.onReady改为圆形遮罩
【完整示例】
import { image } from ‘@kit.ImageKit’;
import { picker } from ‘@kit.CoreFileKit’;
import Matrix4 from ‘@ohos.matrix4’
import fs from ‘@ohos.file.fs’;
import { hilog } from ‘@kit.PerformanceAnalysisKit’;
@Component
export struct CropView {
@State private model: CropModel = new CropModel();
private settings: RenderingContextSettings = new RenderingContextSettings(true);
private context: CanvasRenderingContext2D = new CanvasRenderingContext2D(this.settings);
@State private matrix: object = Matrix4.identity()
.translate({ x: 0, y: 0 })
.scale({ x: this.model.scale, y: this.model.scale});
/** 临时变量，无需手动赋值 /
private tempScale = 1;
/ 临时变量，无需手动赋值 /
private startOffsetX: number = 0;
/ 临时变量，无需手动赋值 **/
private startOffsetY: number = 0;
build() {
Stack() {
Image(this.model.src)
.width(‘100%’)
.height(‘100%’)
.alt(this.model.previewSource)
.objectFit(ImageFit.Contain)
.transform(this.matrix)
.onComplete((msg) => {
if (msg) { // 图片加载成功
this.model.imageWidth = msg.width;
this.model.imageHeight = msg.height;
this.model.componentWidth = msg.componentWidth;
this.model.componentHeight = msg.componentHeight;
this.checkImageAdapt();
        <span class="hljs-keyword"><span class="hljs-keyword">if</span></span> (<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.imageLoadEventListener != <span class="hljs-literal"><span class="hljs-literal">null</span></span> &amp;&amp; msg.loadingStatus == <span class="hljs-number"><span class="hljs-number">1</span></span>) {
          <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.imageLoadEventListener.onImageLoaded(msg);
        }
      }
    })
    .onError((error) =&gt; {
      <span class="hljs-keyword"><span class="hljs-keyword">if</span></span> (<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.imageLoadEventListener != <span class="hljs-literal"><span class="hljs-literal">null</span></span>) {
        <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.imageLoadEventListener.onImageLoadError(error);
      }
    })
  Canvas(<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context)
    .width(<span class="hljs-string"><span class="hljs-string">'100%'</span></span>)
    .height(<span class="hljs-string"><span class="hljs-string">'100%'</span></span>)
    .backgroundColor(Color.Transparent)
    .onReady(() =&gt; {
      <span class="hljs-keyword"><span class="hljs-keyword">if</span></span> (<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context == <span class="hljs-literal"><span class="hljs-literal">null</span></span>) {
        <span class="hljs-keyword"><span class="hljs-keyword">return</span></span>
      }

      <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> height = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.height
      <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> width = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.width
      <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.fillStyle= <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.maskColor;
      <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.fillRect(<span class="hljs-number"><span class="hljs-number">0</span></span>, <span class="hljs-number"><span class="hljs-number">0</span></span>, width, height)

      <span class="hljs-comment"><span class="hljs-comment">// 计算圆形的中心点和半径</span></span>
      <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> centerX = width / <span class="hljs-number"><span class="hljs-number">2</span></span>;
      <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> centerY = height / <span class="hljs-number"><span class="hljs-number">2</span></span>;
      <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> minDimension = <span class="hljs-built_in"><span class="hljs-built_in">Math</span></span>.min(width, height);
      <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> frameRadiusInVp = (minDimension - px2vp(<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.frameWidth)) / <span class="hljs-number"><span class="hljs-number">2</span></span>; <span class="hljs-comment"><span class="hljs-comment">// 减去边框宽度</span></span>

      <span class="hljs-comment"><span class="hljs-comment">// 把中间的取景框透出来</span></span>
      <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.globalCompositeOperation = <span class="hljs-string"><span class="hljs-string">'destination-out'</span></span>
      <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.fillStyle = <span class="hljs-string"><span class="hljs-string">'white'</span></span>
      <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> frameWidthInVp = px2vp(<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.frameWidth);
      <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> frameHeightInVp = px2vp(<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.getFrameHeight());
      <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> x = (width - px2vp(<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.frameWidth)) / <span class="hljs-number"><span class="hljs-number">2</span></span>;
      <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> y = (height - px2vp(<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.getFrameHeight())) / <span class="hljs-number"><span class="hljs-number">2</span></span>;
      <span class="hljs-comment"><span class="hljs-comment">// this.context.fillRect(x, y, frameWidthInVp, frameHeightInVp)</span></span>
      console.info(`width:${width}`)
      console.info(`height:${height}`)
      console.info(`x:${x}`)
      console.info(`y:${y}`)
      console.info(`<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.frameWidth:${<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.frameWidth}`)
      console.info(`<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.getFrameHeight():${<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.getFrameHeight()}`)
      console.info(`frameWidthInVp:${frameWidthInVp}`)
      console.info(`frameHeightInVp:${frameHeightInVp}`)
      console.info(`frameRadiusInVp:${frameRadiusInVp}`)
      <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.beginPath();
      <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.arc(centerX, centerY, px2vp(<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.frameWidth/<span class="hljs-number"><span class="hljs-number">2</span></span>), <span class="hljs-number"><span class="hljs-number">0</span></span>, <span class="hljs-number"><span class="hljs-number">2</span></span> * <span class="hljs-built_in"><span class="hljs-built_in">Math</span></span>.PI);
      <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.fill();

      <span class="hljs-comment"><span class="hljs-comment">// 设置综合操作模式为源覆盖，以便在现有图形上添加新的图形</span></span>
      <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.globalCompositeOperation = <span class="hljs-string"><span class="hljs-string">'source-over'</span></span>;

      <span class="hljs-comment"><span class="hljs-comment">// 设置描边颜色</span></span>
      <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.strokeStyle = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.strokeColor;


      <span class="hljs-comment"><span class="hljs-comment">// 计算圆形的半径，这里我们取正方形边框的较短边的一半作为半径</span></span>
      <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> radius = <span class="hljs-built_in"><span class="hljs-built_in">Math</span></span>.min(frameWidthInVp, frameHeightInVp) / <span class="hljs-number"><span class="hljs-number">2</span></span>;

      <span class="hljs-comment"><span class="hljs-comment">// 开始绘制路径</span></span>
      <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.beginPath();

      <span class="hljs-comment"><span class="hljs-comment">// 使用 arc 方法绘制圆形</span></span>
      <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.arc(centerX, centerY, radius, <span class="hljs-number"><span class="hljs-number">0</span></span>, <span class="hljs-number"><span class="hljs-number">2</span></span> * <span class="hljs-built_in"><span class="hljs-built_in">Math</span></span>.PI);

      <span class="hljs-comment"><span class="hljs-comment">// 关闭路径</span></span>
      <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.closePath();

      <span class="hljs-comment"><span class="hljs-comment">// 描绘圆形边框</span></span>
      <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.lineWidth = <span class="hljs-number"><span class="hljs-number">1</span></span>; <span class="hljs-comment"><span class="hljs-comment">// 边框宽度</span></span>
      <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.context.stroke();

    })
    .enabled(<span class="hljs-literal"><span class="hljs-literal">false</span></span>)
}
.clip(<span class="hljs-literal"><span class="hljs-literal">true</span></span>)
.width(<span class="hljs-string"><span class="hljs-string">'100%'</span></span>)
.height(<span class="hljs-string"><span class="hljs-string">'100%'</span></span>)
.backgroundColor(<span class="hljs-string"><span class="hljs-string">"#00000080"</span></span>)
.priorityGesture(
  TapGesture({ count: <span class="hljs-number"><span class="hljs-number">2</span></span>, fingers: <span class="hljs-number"><span class="hljs-number">1</span></span> })
    .onAction((event:GestureEvent) =&gt; {
      <span class="hljs-keyword"><span class="hljs-keyword">if</span></span>(!event){
        <span class="hljs-keyword"><span class="hljs-keyword">return</span></span>
      }
      <span class="hljs-keyword"><span class="hljs-keyword">if</span></span> (<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.zoomEnabled) {
        <span class="hljs-keyword"><span class="hljs-keyword">if</span></span> (<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.scale != <span class="hljs-number"><span class="hljs-number">1</span></span>) {
          <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.scale = <span class="hljs-number"><span class="hljs-number">1</span></span>;
          <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.reset();
          <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.updateMatrix();
        } <span class="hljs-keyword"><span class="hljs-keyword">else</span></span> {
          <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.zoomTo(<span class="hljs-number"><span class="hljs-number">2</span></span>);
        }
      }

      <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.checkImageAdapt();
    })
)
.gesture(
  GestureGroup(GestureMode.Parallel,
    <span class="hljs-comment"><span class="hljs-comment">// 拖动手势</span></span>
    PanGesture({})
      .onActionStart(() =&gt; {
        hilog.info(<span class="hljs-number"><span class="hljs-number">0</span></span>, <span class="hljs-string"><span class="hljs-string">"CropView"</span></span>, <span class="hljs-string"><span class="hljs-string">"Pan gesture start"</span></span>);
        <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.startOffsetX = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.offsetX;
        <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.startOffsetY = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.offsetY;
      })
      .onActionUpdate((event:GestureEvent) =&gt; {
        hilog.info(<span class="hljs-number"><span class="hljs-number">0</span></span>, <span class="hljs-string"><span class="hljs-string">"CropView"</span></span>, `Pan gesture update: ${<span class="hljs-built_in"><span class="hljs-built_in">JSON</span></span>.stringify(event)}`);
        <span class="hljs-keyword"><span class="hljs-keyword">if</span></span> (event) {
          <span class="hljs-keyword"><span class="hljs-keyword">if</span></span> (<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.panEnabled) {
            <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> distanceX: number = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.startOffsetX + vp2px(event.offsetX) / <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.scale;
            <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> distanceY: number = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.startOffsetY + vp2px(event.offsetY) / <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.scale;
            <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.offsetX = distanceX;
            <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.offsetY = distanceY;
            <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.updateMatrix()
          }
        }
      })
      .onActionEnd(() =&gt; {
        hilog.info(<span class="hljs-number"><span class="hljs-number">0</span></span>, <span class="hljs-string"><span class="hljs-string">"CropView"</span></span>, <span class="hljs-string"><span class="hljs-string">"Pan gesture end"</span></span>);
        <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.checkImageAdapt();
      }),

    <span class="hljs-comment"><span class="hljs-comment">// 缩放手势处理</span></span>
    PinchGesture({ fingers: <span class="hljs-number"><span class="hljs-number">2</span></span> })
      .onActionStart(() =&gt; {
        <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.tempScale = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.scale
      })
      .onActionUpdate((event) =&gt; {
        <span class="hljs-keyword"><span class="hljs-keyword">if</span></span> (event) {
          <span class="hljs-keyword"><span class="hljs-keyword">if</span></span> (!<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.zoomEnabled) <span class="hljs-keyword"><span class="hljs-keyword">return</span></span>;
          <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.zoomTo(<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.tempScale * event.scale);
        }
      })
      .onActionEnd(() =&gt; {
        <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.checkImageAdapt();
      })
  )
)
}
/**

检查手势操作后，图片是否填满取景框，没填满则进行调整
*/
private checkImageAdapt() {
let offsetX = this.model.offsetX;
let offsetY = this.model.offsetY;
let scale = this.model.scale;
hilog.info(0, “CropView”, offsetX: ${offsetX}, offsetY: ${offsetY}, scale: ${scale})

<span class="hljs-comment"><span class="hljs-comment">// 图片适配控件的时候也进行了缩放，计算出这个缩放比例</span></span>
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> widthScale = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.componentWidth / <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.imageWidth;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> heightScale = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.componentHeight / <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.imageHeight;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> adaptScale = <span class="hljs-built_in"><span class="hljs-built_in">Math</span></span>.min(widthScale, heightScale);
hilog.info(<span class="hljs-number"><span class="hljs-number">0</span></span>, <span class="hljs-string"><span class="hljs-string">"CropView"</span></span>, `Image scale ${adaptScale} <span class="hljs-keyword"><span class="hljs-keyword">while</span></span> attaching the component[${<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.componentWidth}, ${<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.componentHeight}]`)

<span class="hljs-comment"><span class="hljs-comment">// 经过两次缩放(适配控件、手势)后，图片的实际显示大小</span></span>
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> showWidth = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.imageWidth * adaptScale * <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.scale;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> showHeight = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.imageHeight * adaptScale * <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.scale;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> imageX = (<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.componentWidth - showWidth) / <span class="hljs-number"><span class="hljs-number">2</span></span>;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> imageY = (<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.componentHeight - showHeight) / <span class="hljs-number"><span class="hljs-number">2</span></span>;
hilog.info(<span class="hljs-number"><span class="hljs-number">0</span></span>, <span class="hljs-string"><span class="hljs-string">"CropView"</span></span>, `Image left top is (${imageX}, ${imageY})`)

<span class="hljs-comment"><span class="hljs-comment">// 取景框的左上角坐标</span></span>
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> frameX = (<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.componentWidth - <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.frameWidth) / <span class="hljs-number"><span class="hljs-number">2</span></span>;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> frameY = (<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.componentHeight - <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.getFrameHeight()) / <span class="hljs-number"><span class="hljs-number">2</span></span>;

<span class="hljs-comment"><span class="hljs-comment">// 图片左上角坐标</span></span>
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> showX = imageX + offsetX * scale;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> showY = imageY + offsetY * scale;
hilog.info(<span class="hljs-number"><span class="hljs-number">0</span></span>, <span class="hljs-string"><span class="hljs-string">"CropView"</span></span>, `Image show at (${showX}, ${showY})`)

<span class="hljs-keyword"><span class="hljs-keyword">if</span></span>(<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.frameWidth &gt; showWidth || <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.getFrameHeight() &gt; showHeight) { <span class="hljs-comment"><span class="hljs-comment">// 图片缩放后，大小不足以填满取景框</span></span>
  <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> xScale = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.frameWidth / showWidth;
  <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> yScale = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.getFrameHeight() / showHeight;
  <span class="hljs-keyword"><span class="hljs-keyword">let</span></span> newScale = <span class="hljs-built_in"><span class="hljs-built_in">Math</span></span>.max(xScale, yScale);
  <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.scale = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.scale * newScale;
  showX *= newScale;
  showY *= newScale;
}

<span class="hljs-comment"><span class="hljs-comment">// 调整x轴方向位置，使图像填满取景框</span></span>
<span class="hljs-keyword"><span class="hljs-keyword">if</span></span>(showX &gt; frameX) {
  showX = frameX;
} <span class="hljs-keyword"><span class="hljs-keyword">else</span></span> <span class="hljs-keyword"><span class="hljs-keyword">if</span></span>(showX + showWidth &lt; frameX + <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.frameWidth) {
  showX = frameX + <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.frameWidth - showWidth;
}
<span class="hljs-comment"><span class="hljs-comment">// 调整y轴方向位置，使图像填满取景框</span></span>
<span class="hljs-keyword"><span class="hljs-keyword">if</span></span>(showY &gt; frameY) {
  showY = frameY;
} <span class="hljs-keyword"><span class="hljs-keyword">else</span></span> <span class="hljs-keyword"><span class="hljs-keyword">if</span></span>(showY + showHeight &lt; frameY + <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.getFrameHeight()) {
  showY = frameY + <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.getFrameHeight() - showHeight;
}
<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.offsetX = (showX - imageX) / scale;
<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.offsetY = (showY - imageY) / scale;
<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.updateMatrix();
}
public zoomTo(scale: number): void {
this.model.scale = scale;
this.updateMatrix();
}
public updateMatrix(): void {
this.matrix = Matrix4.identity()
.translate({ x: this.model.offsetX, y: this.model.offsetY })
.scale({ x: this.model.scale, y: this.model.scale })
}
}
interface ImageLoadedEvent {
width: number;
height: number;
componentWidth: number;
componentHeight: number;
loadingStatus: number;
contentWidth: number;
contentHeight: number;
contentOffsetX: number;
contentOffsetY: number;
}
export interface ImageLoadEventListener {
onImageLoaded(msg: ImageLoadedEvent): void;
onImageLoadError(error: ImageError): void;
}
export class CropModel {
/**

图片uri
类型判断太麻烦了，先只支持string，其他形式的需要先转换成路径
/
src: string = ‘’;
/*
图片预览
/
previewSource: string | Resource = ‘’;
/*
是否可以拖动
/
panEnabled: boolean = true;
/*
是否可以缩放
/
zoomEnabled: boolean = true;
/*
取景框宽度
/
frameWidth = 1000;
/*
取景框宽高比
/
frameRatio = 1;
/*
遮罩颜色
/
maskColor: string = ‘#AA000000’;
/*
取景框边框颜色
/
strokeColor: string = ‘#FFFFFF’;
/*
图片加载监听
*/
imageLoadEventListener: ImageLoadEventListener | null = null;

/// 以下变量不要手动赋值 ///
/**

图片宽度，加载完成之后才会赋值
/
imageWidth: number = 0;
/*
图片高度，加载完成之后才会赋值
/
imageHeight: number = 0;
/*
控件宽度
/
componentWidth: number = 0;
/*
控件高度
/
componentHeight: number = 0;
/*
手势缩放比例
图片经过了两重缩放，一是适配控件的时候进行了缩放，二是手势操作的时候进行了缩放
/
scale: number = 1;
/*
x轴方向偏移量
/
offsetX: number = 0;
/*
y轴方向偏移量
*/
offsetY: number = 0;

/////////////////////////////////////////////
public setImage(src: string, previewSource?: string | Resource): CropModel {
this.src = src;
if (!!previewSource) {
this.previewSource = previewSource;
}
return this;
}
public setScale(scale: number): CropModel {
this.scale = scale;
return this;
}
public isPanEnabled(): boolean {
return this.panEnabled;
}
public setPanEnabled(panEnabled: boolean): CropModel {
this.panEnabled = panEnabled;
return this;
}
public setZoomEnabled(zoomEnabled: boolean): CropModel {
this.zoomEnabled = zoomEnabled;
return this;
}
public setFrameWidth(frameWidth: number) : CropModel {
this.frameWidth = frameWidth;
return this;
}
public setFrameRatio(frameRatio: number) : CropModel {
this.frameRatio = frameRatio;
return this;
}
public setMaskColor(color: string) : CropModel {
this.maskColor = color;
return this;
}
public setStrokeColor(color: string) : CropModel {
this.strokeColor = color;
return this;
}
public setImageLoadEventListener(listener: ImageLoadEventListener) : CropModel {
this.imageLoadEventListener = listener;
return this;
}
public getScale(): number {
return this.scale;
}
public isZoomEnabled(): boolean {
return this.zoomEnabled;
}
public getImageWidth(): number {
return this.imageWidth;
}
public getImageHeight(): number {
return this.imageHeight;
}
public getFrameHeight() {
return this.frameWidth / this.frameRatio;
}
public reset(): void {
this.scale = 1;
this.offsetX = 0;
this.offsetY = 0;
}
public async crop(format: image.PixelMapFormat) : Promise<image.PixelMap> {
<span class="hljs-keyword"><span class="hljs-keyword">if</span></span>(!<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.src || <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.src == <span class="hljs-string"><span class="hljs-string">''</span></span>) {
  <span class="hljs-keyword"><span class="hljs-keyword">throw</span></span> <span class="hljs-keyword"><span class="hljs-keyword">new</span></span> <span class="hljs-built_in"><span class="hljs-built_in">Error</span></span>(<span class="hljs-string"><span class="hljs-string">'Please set src first'</span></span>);
}
<span class="hljs-keyword"><span class="hljs-keyword">if</span></span>(<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.imageWidth == <span class="hljs-number"><span class="hljs-number">0</span></span> || <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.imageHeight == <span class="hljs-number"><span class="hljs-number">0</span></span>) {
  <span class="hljs-keyword"><span class="hljs-keyword">throw</span></span> <span class="hljs-keyword"><span class="hljs-keyword">new</span></span> <span class="hljs-built_in"><span class="hljs-built_in">Error</span></span>(<span class="hljs-string"><span class="hljs-string">'The image is not loaded'</span></span>);
}

<span class="hljs-comment"><span class="hljs-comment">// 图片适配控件的时候也进行了缩放，计算出这个缩放比例</span></span>
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> widthScale = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.componentWidth / <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.imageWidth;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> heightScale = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.componentHeight / <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.imageHeight;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> adaptScale = <span class="hljs-built_in"><span class="hljs-built_in">Math</span></span>.min(widthScale, heightScale);

<span class="hljs-comment"><span class="hljs-comment">// 经过两次缩放(适配控件、手势)后，图片的实际显示大小</span></span>
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> totalScale = adaptScale * <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.scale;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> showWidth = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.imageWidth * totalScale;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> showHeight = <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.imageHeight * totalScale;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> imageX = (<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.componentWidth - showWidth) / <span class="hljs-number"><span class="hljs-number">2</span></span>;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> imageY = (<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.componentHeight - showHeight) / <span class="hljs-number"><span class="hljs-number">2</span></span>;

<span class="hljs-comment"><span class="hljs-comment">// 取景框的左上角坐标</span></span>
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> frameX = (<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.componentWidth - <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.frameWidth) / <span class="hljs-number"><span class="hljs-number">2</span></span>;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> frameY = (<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.componentHeight - <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.getFrameHeight()) / <span class="hljs-number"><span class="hljs-number">2</span></span>;

<span class="hljs-comment"><span class="hljs-comment">// 图片左上角坐标</span></span>
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> showX = imageX + <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.offsetX * <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.scale;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> showY = imageY + <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.offsetY * <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.scale;

<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> x = (frameX - showX) / totalScale;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> y = (frameY - showY) / totalScale;
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> file = fs.openSync(<span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.src, fs.OpenMode.READ_ONLY)
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> imageSource : image.ImageSource = image.createImageSource(file.fd);
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> decodingOptions : image.DecodingOptions = {
  editable: <span class="hljs-literal"><span class="hljs-literal">true</span></span>,
  desiredPixelFormat: image.PixelMapFormat.BGRA_8888,
}

<span class="hljs-comment"><span class="hljs-comment">// 创建pixelMap</span></span>
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> pm = await imageSource.createPixelMap(decodingOptions);
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> cp = await <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.copyPixelMap(pm);
pm.release();
<span class="hljs-keyword"><span class="hljs-keyword">let</span></span> region: image.Region = { x: x, y: y, size: { width: <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.frameWidth / totalScale, height: <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.getFrameHeight() / totalScale } };
cp.cropSync(region);
<span class="hljs-keyword"><span class="hljs-keyword">return</span></span> cp;
}
async copyPixelMap(pm: PixelMap): Promise<PixelMap> {
const imageInfo: image.ImageInfo = await pm.getImageInfo();
const buffer: ArrayBuffer = new ArrayBuffer(pm.getPixelBytesNumber());
// TODO 知识点：通过readPixelsToBuffer实现PixelMap的深拷贝，其中readPixelsToBuffer输出为BGRA_8888
await pm.readPixelsToBuffer(buffer);
// TODO 知识点：readPixelsToBuffer输出为BGRA_8888,此处createPixelMap需转为RGBA_8888
const opts: image.InitializationOptions = {
editable: true,
pixelFormat: image.PixelMapFormat.RGBA_8888,
size: { height: imageInfo.size.height, width: imageInfo.size.width }
};
return image.createPixelMap(buffer, opts);
}
}
interface MyEvent {
result: FileSelectorResult,
fileSelector: FileSelectorParam
}
@Entry
@Component
struct Page23 {
@State pm: PixelMap | undefined = undefined;
@State private model: CropModel = new CropModel();
build() {
Column() {
CropView({
model: this.model,
})
.layoutWeight(1)
.width(‘100%’)
Button(‘打开相册’).onClick(()=>{
this.openPicker()
})
Button(‘测试剪裁’).onClick(async () => {
try {
this.pm = await this.model.crop(image.PixelMapFormat.RGBA_8888);
} catch (e) {
console.info(e:${<span class="hljs-built_in"><span class="hljs-built_in">JSON</span></span>.stringify(e)})
}
})
Text(‘剪裁结果’)
Image(this.pm).width(‘300lpx’).height(‘300lpx’).borderRadius(‘150lpx’)
}
.height(‘100%’)
.width(‘100%’)
}
// 弹出图片选择器方法
async openPicker() {
try {
// 设置图片选择器选项
const photoSelectOptions = new picker.PhotoSelectOptions();
// 限制只能选择一张图片
photoSelectOptions.MIMEType = picker.PhotoViewMIMETypes.IMAGE_TYPE;
photoSelectOptions.maxSelectNumber = 1;
// 创建并实例化图片选择器
const photoViewPicker = new picker.PhotoViewPicker();
// 选择图片并获取图片URI
let uris: picker.PhotoSelectResult = await photoViewPicker.select(photoSelectOptions);
if (!uris || uris.photoUris.length === 0) return;
// 获取选中图片的第一张URI
let uri: string = uris.photoUris[0];
this.model.setImage(uri)
.setFrameWidth(1000)
.setFrameRatio(1);
} catch (e) {
console.error(‘openPicker’, JSON.stringify(e));
}
}
handleFileSelection(event: MyEvent) {
const PhotoSelectOptions = new picker.PhotoSelectOptions();
PhotoSelectOptions.MIMEType = picker.PhotoViewMIMETypes.IMAGE_TYPE;
PhotoSelectOptions.maxSelectNumber = 1;
<span class="hljs-keyword"><span class="hljs-keyword">const</span></span> photoPicker = <span class="hljs-keyword"><span class="hljs-keyword">new</span></span> picker.PhotoViewPicker();

photoPicker.select(PhotoSelectOptions)
  .then((PhotoSelectResult) =&gt; {
    <span class="hljs-keyword"><span class="hljs-keyword">if</span></span> (PhotoSelectResult.photoUris.length === <span class="hljs-number"><span class="hljs-number">0</span></span>) {
      console.warn(<span class="hljs-string"><span class="hljs-string">'No image selected.'</span></span>);
      <span class="hljs-keyword"><span class="hljs-keyword">return</span></span>;
    }

    <span class="hljs-keyword"><span class="hljs-keyword">const</span></span> srcUri = PhotoSelectResult.photoUris[<span class="hljs-number"><span class="hljs-number">0</span></span>];
    <span class="hljs-keyword"><span class="hljs-keyword">this</span></span>.model.setImage(srcUri)
      .setFrameWidth(<span class="hljs-number"><span class="hljs-number">1000</span></span>)
      .setFrameRatio(<span class="hljs-number"><span class="hljs-number">1</span></span>);
  })
  .catch((selectError: object) =&gt; {
    console.error(<span class="hljs-string"><span class="hljs-string">'Failed to invoke photo picker:'</span></span>, <span class="hljs-built_in"><span class="hljs-built_in">JSON</span></span>.stringify(selectError));
  });

<span class="hljs-keyword"><span class="hljs-keyword">return</span></span> <span class="hljs-literal"><span class="hljs-literal">true</span></span>;
}
}<button style="position: absolute; padding: 4px 8px 0px; cursor: pointer; top: 8px; right: 8px; font-size: 14px;">复制</button>
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