create-canvas-context-async: 处理编译警告问题

pages/API/create-canvas-context-async/create-canvas-context-async.uvue

@@ -376,14 +376,14 @@
       pattern() {
         const context = this.canvasContext!
 
-        this.image = new Image(100, 100)
-        this.image!.src = '../../../static/api.png';
+        const image = new Image(100, 100)
+        image.src = '../../../static/api.png';
         // Only use the image after it's loaded
-        this.image!.onload = () => {
+        image!.onload = () => {
           context.save()
           context.clearRect(0, 0, this.canvasWidth, this.canvasHeight)
-          const pattern = context.createPattern(this.image!, "repeat")
-          // context.fillStyle = pattern
+          const pattern = context.createPattern(image!, "repeat")
+          context.fillStyle = pattern
           context.fillRect(0, 0, 100, 100)
           context.restore()
         };