鸿蒙OpenHarmony实战开发-MiniCanvas

news2024/11/24 3:31:30

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%"})
  }
}