@performance/nested-post-frame-callback-check

postFrameCallback会请求vsync，循环嵌套调用postFrameCallback会导致一直请求vsync，从而引起无效渲染问题。

规则配置

// code-linter.json5
{
  "rules": {
    "@performance/nested-post-frame-callback-check": "suggestion",
  }
}

选项

该规则无需配置额外选项。

正例

import {FrameCallback } from '@kit.ArkUI';
class MyFrameCallback extends FrameCallback {
  private tag: string;
  constructor(tag: string) {
    super();
    this.tag = tag;
  }
  onFrame(frameTimeNanos: number) {
    console.info('MyFrameCallback ' + this.tag + ' ' + frameTimeNanos.toString());
  }
}
@Entry
@Component
struct Index {
  build() {
    Row() {
      Button('Invoke postFrameCallback')
        .onClick(() => {
          this.getUIContext().postFrameCallback(new MyFrameCallback("normTask"));
        })
    }
  }
}

反例

import { FrameCallback, UIContext } from '@kit.ArkUI';
class MyFrameCallback extends FrameCallback {
  private tag: string;
  constructor(tag: string) {
    super();
    this.tag = tag;
    const uiContext = new UIContext();
    uiContext.postFrameCallback(new MyFrameCallback1("normTask1"));
  }
  onFrame(frameTimeNanos: number) {
    new UIContext().postFrameCallback(new MyFrameCallback1("normTask1"));
    console.info('MyFrameCallback ' + this.tag + ' ' + frameTimeNanos.toString());
  }
}
class MyFrameCallback1 extends FrameCallback {
  private tag: string;
  constructor(tag: string) {
    super();
    this.tag = tag;
  }
  onFrame(frameTimeNanos: number) {
    console.info('MyFrameCallback1 ' + this.tag + ' ' + frameTimeNanos.toString());
  }
}
@Entry
@Component
struct Index {
  build() {
    Row() {
      Button('Nested postFrameCallback')
        .onClick(() => {
          this.getUIContext().postFrameCallback(new MyFrameCallback("normTask"));
        })
    }
  }
}

规则集

plugin:@performance/all

Code Linter代码检查规则的配置指导请参考Code Linter代码检查。