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Humboldt NEXT How can I use @Styles decorator to optimize my component code?

Popularity：1 ℃/2024-10-17 10:43:21

Hello everyone, I am V. In the development of Hongmeng NEXT@Styles Decorators are a very useful method for defining reusable styles. This allows developers to distill multiple style settings into a single method that can be reused across multiple components, thus improving code maintainability and readability. The following@Styles Detailed usage and application scenario examples of decorators.

@Styles Instructions for using the decorator

  1. Only generic properties and events are supported: Current@Styles Applies only to generic properties and events; properties or events specific to a component are not supported.
  2. Parameters not supported：@Styles Methods cannot take parameters. For example, the following is an example of incorrect usage:
   @Styles function globalStyles(value: number) {
     .width(value)
   }

The correct way to do this is without parameters:

   @Styles function globalStyles() {
     .width(150)
     .height(100)
     .backgroundColor()
   }
  1. Define Position：@Styles It can be defined within a component or globally. When defined globally, the method name needs to be preceded by thefunction keyword; when defined within a component, it is not required.
   // global definition
   @Styles function globalStyles() {
     .width(150)
     .height(100)
     .backgroundColor()
   }

   // In-component definition
   @Component
   struct FancyComponent {
     @Styles myStyle() {
       .width(200)
       .height(100)
       .backgroundColor()
     }
   }
  1. Accessing the internal state of a component: Defined within the component@Styles This can be done bythis access to the component's constants and state variables, and can be used in the@Styles The value of a state variable is changed by an event in the state variable.
   @Component
   struct MyComponent {
     @State heightValue: number = 100
     @Styles myStyle() {
       .height()
       .backgroundColor()
       .onClick(() => {
          = 200
       })
     }
   }
  1. prioritization: Within the component@Styles has a higher priority than the global@Styles. The framework prioritizes finding the current component within the@Styles, if it is not found, it will be looked up globally.

Let's look at a case study.

The following is an example of how to use the@Styles Decorator example showing how to define styles globally and within a component, and use those styles within the component.

// Defining global styles
@Styles function globalStyles() {
  .width(150)
  .height(100)
  .backgroundColor()
}

@Entry
@Component
struct StyleUse {
  @State heightValue: number = 100
  // Defining In-Component Styles
  @Styles myStyle() {
    .width(200)
    .height()
    .backgroundColor()
    .onClick(() => {
       = 200
    })
  }

  build() {
    Column({ space: 10 }) {
      // Using Global Styles
      Text('FancyA').globalStyles().fontSize(30)
      // Using In-Component Styles
      Text('FancyB').myStyle().fontSize(30)
    }
  }
}

In this case, we define a global styleglobalStyles and an in-component stylemyStyleThe InStyleUse integrated componentbuild method, we use these styles to set the twoText component's style. This shows how to style a component with the@Styles Decorators reuse styles , making the code more concise and easy to maintain .

How can I use @Styles decorator to optimize my component code?

utilization@Styles Decorators can significantly optimize your component code, making it cleaner, more maintainable, and reducing duplicate style code. Here's how to use@Styles Steps and examples of decorators to optimize component code:

1. Recognize duplicate style codes

First, you need to identify style codes that are reused across multiple components. These could be generic layout styles, colors, font sizes, etc.

2. Definitions@Styles methodologies

Distill these duplicate style codes into one or more@Styles methods. You can define these methods inside the component or globally.

  • In-Component Styling: If the style is only used in a single component, it can be defined inside that component.@Styles Methods.
  • Global Style: If the style is used in more than one component, it can be defined as a global@Styles Methods.

3. Applications@Styles methodologies

In the component'sbuild method, applying these by means of method calls in the@Styles method to the appropriate UI component.

4. Use of status and events

If desired, you can add the@Styles method uses the component's state and event handlers so that the style can change dynamically based on the component's state.

Optimization example

Let's say you have an application where multiple pages have warning messages that need to be displayedText component, the style of the warning message is consistent across all pages: red, bold, and font size 16.

Step 1: Define Global@Styles methodologies

// Define global warning styles
@Styles function warningStyle() {
  .fontSize(16)
  .fontWeight()
  .fontColor()
}

Step 2: Use the@Styles methodologies

@Entry
@Component
struct WarningMessage {
  build() {
    Column() {
      // Use the global warning style
      Text('This is a warning message').warningStyle()
    }
  }
}

In this example, we define a global warning stylewarningStyleand inWarningMessage The style is applied in the component. This way, no matter what part of the application needs to display the warning message, you can simply call the.warningStyle() method to apply the style without having to rewrite the style code.

summarize

By using the@Styles decorators, you can separate the style logic from the component's business logic, making the code clearer and easier to manage. This not only reduces code duplication, but also makes style modification and maintenance more centralized and efficient. The light boat has crossed ten thousand mountains, the momentum of Hongmeng is unstoppable. Concerned about Wei brother love programming, together mixed into the Hongmeng ecological.

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