fix: 修复低版本安卓上 canvas 绘制坐标比实际值小的问题 question/105866

src/core/helpers/hidpi.js

@@ -158,5 +158,8 @@ if (pixelRatio !== 1) {
 export function wrapper (canvas) {
   canvas.width = canvas.offsetWidth * pixelRatio
   canvas.height = canvas.offsetHeight * pixelRatio
-  canvas.getContext('2d').__hidpi__ = true
+  canvas.__hidpi__ = true
+  // 避免低版本安卓上 context 实例被回收
+  canvas.__context2d__ = canvas.getContext('2d')
+  canvas.__context2d__.__hidpi__ = true
 }

src/core/view/components/canvas/index.vue

@@ -107,10 +107,7 @@ export default {
     this._images = {}
   },
   mounted () {
-    this._resize({
-      width: this.$refs.sensor.$el.offsetWidth,
-      height: this.$refs.sensor.$el.offsetHeight
-    })
+    this._resize()
   },
   beforeDestroy () {
     const canvas = this.$refs.canvas
@@ -131,10 +128,10 @@ export default {
       if (canvas.width > 0 && canvas.height > 0) {
         var context = canvas.getContext('2d')
         var imageData = context.getImageData(0, 0, canvas.width, canvas.height)
-        wrapper(this.$refs.canvas)
+        wrapper(canvas)
         context.putImageData(imageData, 0, 0)
       } else {
-        wrapper(this.$refs.canvas)
+        wrapper(canvas)
       }
     },
     _touchmove (event) {