Home Web Front-end uni-app How to change the value in data in uniapp method

How to change the value in data in uniapp method

Apr 27, 2023 am 09:04 AM

UniApp is a cross-platform development framework that can be developed and deployed on multiple platforms. In UniApp development, we often need to change the value in data in the method to implement business logic. However, if we don't understand how data is used in UniApp, we may encounter some problems.

In UniApp, we can declare data through the data attribute of the component, and use the setData method in the component method to change the value in data. The setData method is asynchronous, so we need to pay attention to the writing method.

The following is an example:

<template>
  <view>{{message}}</view>
</template>

<script>
export default {
  data() {
    return {
      message: 'Hello World!'
    }
  },
  methods: {
    changeMessage() {
      this.setData({
        message: 'Hello UniApp!'
      }, () => {
        console.log('data已经更新'); // data已经更新
      })
    }
  }
}
</script>
Copy after login

In the above example, we declared a data attribute named message and used it in the component's template. In the component method, we change the value of the message by calling the setData method. It should be noted that we use a callback function in the second parameter of the setData method to perform other operations after the data is updated.

In addition, it should be noted that although we use the this.setData method to update the page data, this is actually what the Vue framework does at the bottom. The Vue framework will automatically update the page when the data is updated. Therefore, the way to update page data in UniApp is different from that in pure JavaScript.

In addition to using the setData method in the method to change the value in data, we can also calculate new values ​​based on the value of data through calculated properties. The following is an example:

<template>
  <view>{{fullName}}</view>
</template>

<script>
export default {
  data() {
    return {
      firstName: '张',
      lastName: '三'
    }
  },
  computed: {
    fullName() {
      return this.firstName + this.lastName
    }
  }
}
</script>
Copy after login

In the above example, we declare two data properties named firstName and lastName, and calculate a new one based on the values ​​of these two properties in the calculated property fullName value. The computed property fullName is ultimately used in the template of the rendered component.

In addition to the above methods, we can also use the watch method to monitor data changes and perform some operations when the changes occur.

In short, in UniApp, we can change the value in data through methods, calculated properties and watch methods to implement corresponding business logic. It is important to understand the asynchronous nature of the setData method and note that the page data is updated differently than in pure JavaScript.

The above is the detailed content of How to change the value in data in uniapp method. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

What are the different types of testing that you can perform in a UniApp application? What are the different types of testing that you can perform in a UniApp application? Mar 27, 2025 pm 04:59 PM

The article discusses various testing types for UniApp applications, including unit, integration, functional, UI/UX, performance, cross-platform, and security testing. It also covers ensuring cross-platform compatibility and recommends tools like Jes

How can you reduce the size of your UniApp application package? How can you reduce the size of your UniApp application package? Mar 27, 2025 pm 04:45 PM

The article discusses strategies to reduce UniApp package size, focusing on code optimization, resource management, and techniques like code splitting and lazy loading.

How can you use lazy loading to improve performance? How can you use lazy loading to improve performance? Mar 27, 2025 pm 04:47 PM

Lazy loading defers non-critical resources to improve site performance, reducing load times and data usage. Key practices include prioritizing critical content and using efficient APIs.

What debugging tools are available for UniApp development? What debugging tools are available for UniApp development? Mar 27, 2025 pm 05:05 PM

The article discusses debugging tools and best practices for UniApp development, focusing on tools like HBuilderX, WeChat Developer Tools, and Chrome DevTools.

How can you optimize images for web performance in UniApp? How can you optimize images for web performance in UniApp? Mar 27, 2025 pm 04:50 PM

The article discusses optimizing images in UniApp for better web performance through compression, responsive design, lazy loading, caching, and using WebP format.

How can you optimize the loading speed of your UniApp application? How can you optimize the loading speed of your UniApp application? Mar 27, 2025 pm 04:43 PM

The article discusses strategies to optimize UniApp loading speed, focusing on minimizing bundle size, optimizing media, caching, code splitting, using CDNs, and reducing network requests.

How can you optimize network requests in UniApp? How can you optimize network requests in UniApp? Mar 27, 2025 pm 04:52 PM

The article discusses strategies for optimizing network requests in UniApp, focusing on reducing latency, implementing caching, and using monitoring tools to enhance application performance.

What are some common performance anti-patterns in UniApp? What are some common performance anti-patterns in UniApp? Mar 27, 2025 pm 04:58 PM

The article discusses common performance anti-patterns in UniApp development, such as excessive global data use and inefficient data binding, and offers strategies to identify and mitigate these issues for better app performance.

See all articles