鸿蒙OpenHarmony开发实战：【MiniCanvas】

介绍

基于OpenHarmony的Cavas组件封装了一版极简操作的MiniCanvas，屏蔽了原有Canvas内部复杂的调用流程，支持一个API就可以实现相应的绘制能力，该库还在继续完善中，也欢迎PR。

使用说明

1. 添加MiniCanvas依赖

   在项目entry目录执行如下命令安装MiniCanvas库：

   npm install git+https://gitee.com/ark-ui/MiniCanvas.git
   

2. 引入MiniCanvas

   import { MiniCanvas, Paint, ICanvas } from '@ohos/mini_canvas'
   

3. 使用MiniCanvas

   @Entry @Component struct TestMiniCanvas {
     build() {
       Column() {
         MiniCanvas({
           onDraw: (canvas) => {
             
           }
         })
       }
       .size({width: "100%", height: "100%"})
     }
   }
   

4. MiniCanvas绘制

   // import { MiniCanvas, Paint, ICanvas } from '@ohos/mini_canvas'
   // 源码方式引入
   import { MiniCanvas, Paint } from "./mini_canvas"
   
   @Entry @Component struct TestMiniCanvas {
     build() {
       Column() {
         MiniCanvas({
           // 在onDraw()方法内执行绘制
           onDraw: (canvas) => {
             // 创建画笔
             let paint = new Paint()
   
             // 绘制直线
             paint.setColor("#FF0000");
             paint.setStrokeWidth(5);
             canvas.drawLine(10, 10, 280, 10, paint);
   
             // 绘制圆以及圆环
             canvas.drawCircle(50, 50, 25, paint);
             paint.setStroke(true);
             paint.setStrokeWidth(3);
             canvas.drawCircle(250, 50, 25, paint);
   
             // 绘制椭圆以及椭圆环
             paint.setStroke(false);
             canvas.drawOval(20, 100, 150, 50, paint)
             paint.setStroke(true);
             paint.setColor(Color.Pink.toString())
             canvas.drawOval(190, 100, 150, 50, paint)
   
             // 绘制矩形
             paint.setStroke(false)
             canvas.drawRect(20, 180, 150, 50, paint)
             paint.setStroke(true)
             paint.setStrokeWidth(5)
             canvas.drawRect(190, 180, 150, 50, paint)
   
             // 绘制圆角矩形
             paint.setStroke(false);
             canvas.drawRoundRect(20, 250, 150, 50, 10, paint)
             paint.setStroke(true);
             canvas.drawRoundRect(190, 250, 150, 50, 10, paint)
   
   
             // 绘制圆弧
             canvas.drawArc(80, 330, 40, 0, 135, paint);
             paint.setStroke(false);
             canvas.drawArc(250, 330, 40, 0, 135, paint);
   
             // 绘制图片
             let bitmap = new ImageBitmap("pages/test.jpg")
             canvas.drawImage(bitmap, 10, 10, 800, 600, 20, 400, 320, 160, paint)
           },
           // 设置画布的属性
           attribute: {
             id: "mini_canvas",
             width: "100%",
             height: "100%",
             background: "#ffffff",
             clickListener: (event) => {
               console.log("onClicked: " + JSON.stringify(event));
             },
             touchListener: (event) => {
               console.log("onTouched: " + JSON.stringify(event));
             }
           },
         })
       }
       .size({width: "100%", height: "100%"})
     }
   }
   

5. 运行结果