uni-app TypeError: Cannot read properties of undefined (reading 'onLoad')

uni-app TypeError: Cannot read properties of undefined (reading ‘onLoad’)

示例代码：

<template>  
    <view class="content">  
        <image class="logo" src="/static/logo.png"></image>  
        <view class="text-area">  
            <text class="title">{{title}}</text>  
        </view>  
    </view>  
</template>  

<script>  
    export default {  
        data() {  
            return {  
                title: 'Hello'  
            }  
        },  
        onLoad() {  

        },  
        methods: {  

        }  
    }  
</script>  

<style>  
    .content {  
        display: flex;  
        flex-direction: column;  
        align-items: center;  
        justify-content: center;  
    }  

    .logo {  
        height: 200rpx;  
        width: 200rpx;  
        margin-top: 200rpx;  
        margin-left: auto;  
        margin-right: auto;  
        margin-bottom: 50rpx;  
    }  

    .text-area {  
        display: flex;  
        justify-content: center;  
    }  

    .title {  
        font-size: 36rpx;  
        color: #8f8f94;  
    }  
</style>

操作步骤：

使用hbuilderx工具新建uniapp项目，选择默认模板，vue版本选择vue3，不勾选uni-app x选项以及启用uniCloud选项。创建成功后发布为华为快应用，使用华为快应用打开发布的包，运行到调试手机。

预期结果：

正常显示基础效果

实际结果：

报错

bug描述：

使用HBuilderx工具创建了一个基础的vue3项目，打包为华为快应用。运行到华为快应用工具后报错信息如下：

03-08 16:23:19.510 E/jsLog   (24926): Runtime Error, Page : pages/index/index  
03-08 16:23:19.510 E/jsLog   (24926): Runtime Error, ErrorCode :   
03-08 16:23:19.511 E/jsLog   (24926): TypeError: Cannot read properties of undefined (reading 'onLoad')  
03-08 16:23:19.511 E/jsLog   (24926):     at Yi (hbs:3090:22)  
03-08 16:23:19.511 E/jsLog   (24926):     at Component.attached (hbs:3012:13)  
03-08 16:23:19.511 E/jsLog   (24926):     at hbs-frk:1:221816  
03-08 16:23:19.511 E/jsLog   (24926):     at Array.forEach (<anonymous>)  
03-08 16:23:19.511 E/jsLog   (24926):     at t (hbs-frk:1:221789)  
03-08 16:23:19.511 E/jsLog   (24926):     at Component.disposeLifetime (hbs-frk:1:221970)  
03-08 16:23:19.511 E/jsLog   (24926):     at hbs-frk:1:223117  
03-08 16:23:19.511 E/jsLog   (24926):     at Array.forEach (<anonymous>)  
03-08 16:23:19.511 E/jsLog   (24926):     at Component._triggerLifetime (hbs-frk:1:223081)  
03-08 16:23:19.511 E/jsLog   (24926):     at triggerLifetime (hbs-frk:1:236564)

更多关于uni-app TypeError: Cannot read properties of undefined (reading 'onLoad')的实战教程也可以访问 https://www.itying.com/category-93-b0.html

3 回复

感谢您的反馈，已复现该问题，已加分，我们排查一下

更多关于uni-app TypeError: Cannot read properties of undefined (reading 'onLoad')的实战教程也可以访问 https://www.itying.com/category-93-b0.html


有结果了吗

The error TypeError: Cannot read properties of undefined (reading 'onLoad') in uni-app typically occurs when you’re trying to access a method or property on an object that is undefined. This can happen for several reasons, such as:

  1. Component Lifecycle Issue: You might be trying to access onLoad in a context where it doesn’t exist or hasn’t been initialized yet.

  2. Incorrect Context: You might be trying to access onLoad on an object that is not correctly defined or initialized.

  3. Syntax or Reference Error: There might be a typo or incorrect reference in your code.

Common Scenarios and Solutions

1. Component Lifecycle Issue

Ensure that you are calling onLoad within the correct lifecycle hook of a page or component. In uni-app, onLoad is a lifecycle hook that is specific to pages, not components.

  • For Pages:

    export default {
  onLoad(options) {
    // Your code here
  }
}

  • For Components: Components do not have an onLoad lifecycle hook. Instead, you should use created or mounted.

    export default {
  created() {
    // Your code here
  },
  mounted() {
    // Your code here
  }
}

2. Incorrect Context

If you’re trying to access onLoad on an object that is undefined, ensure that the object is properly initialized before you try to access its methods or properties.

For example, if you have something like this:

let myObject;
myObject.onLoad(); // This will throw an error because myObject is undefined

Make sure to initialize myObject before calling onLoad:

let myObject = {
  onLoad: function() {
    console.log('onLoad called');
  }
};
myObject.onLoad(); // This will work

3. Syntax or Reference Error

Double-check your code for any typos or incorrect references. For example, if you mistakenly wrote onload instead of onLoad, it could cause this error.

export default {
  onload(options) { // Typo: should be 'onLoad'
    // Your code here
  }
}

Correct it to:

export default {
  onLoad(options) {
    // Your code here
  }
}
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