AnimationFrame: 优化更新页面策略

pages/API/animation-frame/animation-frame.uvue

@@ -3,7 +3,7 @@
     <page-head :title="title"></page-head>
     <button @click="startRequestAnimationFrame">requestAnimationFrame</button>
     <button @click="stopRequestAnimationFrame">cancelAnimationFrame</button>
-    <text class="frame-count">FPS: {{fps}} / {{formatFPSTime}}</text>
+    <text class="frame-count">FPS: {{FPSString}}</text>
     <text class="frame-count">FrameCount: {{testFrameCount}}</text>
     <text class="tips">提示: 在当前测试例子中，每增加一次调用 requestAnimationFrame 帧率翻倍，cancelAnimationFrame 后恢复</text>
   </view>
@@ -15,8 +15,7 @@
       return {
         title: 'AnimationFrame',
         taskId: 0,
-        fps: 0,
-        formatFPSTime: '0ms',
+        FPSString: '- / -ms',
         lastTime: 0,
         frameCount: 0,
         testFrameCount: 0
@@ -30,24 +29,25 @@
     methods: {
       startRequestAnimationFrame() {
         this.taskId = requestAnimationFrame((timestamp : number) => {
-          this.frameCount++
-          if (timestamp - this.lastTime >= 1000) {
-            this.formatFPSTime = (1000 / this.frameCount).toFixed(3) + 'ms'
-            this.fps = this.frameCount
-            this.frameCount = 0
-            this.lastTime = timestamp
-          }
-
+          this.updateFPS(timestamp)
           this.testFrameCount++
           this.startRequestAnimationFrame()
         })
       },
       stopRequestAnimationFrame() {
-        this.fps = 0
-        this.formatFPSTime = '0ms'
+        cancelAnimationFrame(this.taskId)
         this.lastTime = 0
         this.frameCount = 0
-        cancelAnimationFrame(this.taskId)
+        this.FPSString = '- / -ms'
+      },
+      updateFPS(timestamp : number) {
+        this.frameCount++
+        if (timestamp - this.lastTime >= 1000) {
+          const timeOfFrame = (1000 / this.frameCount)
+          this.FPSString = `${this.frameCount} / ${timeOfFrame.toFixed(3)}ms`
+          this.frameCount = 0
+          this.lastTime = timestamp
+        }
       }
     }
   }