HarmonyOS 鸿蒙Next--emitter订阅状态变化显示隐藏自定义弹窗Loading

0、使用emitter来控制自定义弹窗的显示隐藏，如网络请求开始前弹出自定义loading弹窗，网络请求结束后隐藏弹窗

1、emitter发送消息

  showLoad(show: boolean) {
let eventData: emitter.EventData = {
data: {
“showLoad”: show,
}
};
let options: emitter.Options = {
priority: emitter.EventPriority.IMMEDIATE
};
emitter.emit(EmitterId.LOAD_PROGRESS, options, eventData)
}

2、自定义Loading弹窗接收emitter消息

import emitter from ‘@ohos.events.emitter’;
import { EmitterId } from ‘…/…/constants/EmitterId’;
import { LoadingProgressDialog } from ‘./LoadingProgressDialog’;

export class CustomDialogCallback {
confirmCallback: Function = () => {
};
cancelCallback: Function = () => {
};
}
@Component
export struct CustomDialogView {
@Provide dialogCallBack: CustomDialogCallback = new CustomDialogCallback();
loadingDialog: CustomDialogController = new CustomDialogController({
builder: LoadingProgressDialog(),
autoCancel: true,
alignment:DialogAlignment.Center,
customStyle: true
});
aboutToAppear() {
emitter.on(EmitterId.LOAD_PROGRESS, (res: emitter.EventData) => {
if (res.data?.showLoad) {
if (this.loadingDialog) {
this.loadingDialog.open();
}
} else {
if (this.loadingDialog) {
this.loadingDialog.close();
}
}
})
}
aboutToDisappear() {
emitter.off(EmitterId.LOAD_PROGRESS)
}
build() {
}
} 

3、自定义Loading弹窗

import { R } from ‘@ohos/res’;

@Preview
@CustomDialog
export struct LoadingProgressDialog {
controller: CustomDialogController = new CustomDialogController({ builder: ‘’ });
build() {
Column() {
LoadingProgress()
.width(80)
.height(80)
.color("#FF0000");
Text(“加载中…”)
.margin({ top: R.float.vp10, bottom: R.float.vp10 });
}
.width(140)
.height(160)
.alignItems(HorizontalAlign.Center)
.justifyContent(FlexAlign.Center)
.borderRadius(R.float.vp10)
.backgroundColor(Color.White)
}
}