How to dynamically change the src attribute of an image in uniapp

With the widespread use of mobile applications, the development of front-end technology has gradually shifted from the web to the mobile terminal. Adapting to different mobile terminal platforms has become an issue that developers must consider. For this reason, a variety of mobile frameworks have emerged. Among these frameworks, the uniapp framework has gradually become the most popular choice among developers. In the uniapp framework, I believe many developers will encounter the problem of dynamically changing the image src when processing images. This article will explain in detail the solution to this problem.

1. Use of image component in uniapp

In the uniapp framework, introducing images requires the use of the image component, the syntax is as follows:

<template>
    <image :src="imageUrl"></image>
</template>

<script>
    export default {
        data() {
            return {
                imageUrl: 'https://www.example.com/example.jpg'
            }
        }
    }
</script>

In the above In the code, we bind a variable imageUrl to the src attribute of the image component through the v-bind instruction. This variable is defined in data, and its initial value is the URL of an image. In this way, the image component will render the corresponding image through this url.

When we need to dynamically change the src of the image in the component, we need to change the value of this variable. Note: We can only change the value defined by the variable, because directly changing the src attribute of the component is invalid.

2. Dynamically change the src of the image in the image component

In uniapp, we can add logic in the method to change the value of imageUrl to reflect it on the page. We first add a button button under the template area and add a click event addImage to the button. The code is as follows:

<template>
    <view>
        <image :src="imageUrl"></image>
        <button @tap="addImage">添加图片</button>
    </view>
</template>

Then we define an empty array images under the script area to store the image URL and define an The counter count is used to count the number of images:

<script>
    export default {
        data() {
            return {
                imageUrl: '',
                images: [],
                count: 0
            }
        },
        methods: {
            addImage() {
                let num = ++this.count;
                let url = `https://www.example.com/example${num}.jpg`;
                this.images.push(url);
                this.imageUrl = url;
            }
        }
    }
</script>

In the addImage method, we use the counter to generate a unique image URL, push it into the images array, and then assign the last URL to imageUrl. Since the imageUrl variable is bound to the src attribute of the image component, when the value of the variable changes, the image will automatically refresh. In this way, we have achieved the purpose of dynamically changing the src of the image in the image component.

3. Summary

Through the introduction of this article, we can know that in uniapp, to dynamically change the src of the image in the image component, you only need to change the variables in the component Just value. This method is not only simple and easy to implement, but also can cope with the need to change the component src at runtime. I hope this article can help everyone.

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