Android使用继承View类来绘图
16lz
2022-06-15
添加新类MyView继承View
在MyView中实例化Paint
1 package com.hu.viewdemo; 2 3 import android.content.Context; 4 import android.graphics.Canvas; 5 import android.graphics.Color; 6 import android.graphics.Paint; 7 import android.graphics.Paint.Style; 8 import android.graphics.Path; 9 import android.view.View;10 11 public class MyView extends View{12 13 private Paint paint;//画笔14 15 public MyView(Context context) {16 super(context);17 // TODO Auto-generated constructor stub18 paint = new Paint();19 paint.setColor(Color.RED);//设置画笔颜色20 paint.setAntiAlias(true);//设置抗锯齿21 paint.setStyle(Style.STROKE);//设置为空心22 paint.setStrokeWidth(1);//设置空心边距为123 paint.setTextSize(40);//设置字符串高24 }25 26 @Override27 protected void onDraw(Canvas canvas) {28 // TODO Auto-generated method stub29 super.onDraw(canvas);30 canvas.drawCircle(100, 100, 20, paint);//画个圆31 canvas.drawText("这是字符串", 0, 40, paint);//写字,指定左下角位置32 canvas.drawRect(100, 200, 200, 300, paint);//画矩形33 Path path=new Path();//创建路径34 path.moveTo(300, 200);35 path.lineTo(300, 300);36 path.lineTo(200, 400);//指定路径37 canvas.drawPath(path, paint);//沿路径绘图38 }39 40 }
然后在activity类中将MyView的实例设为ContentView
1 package com.hu.viewdemo; 2 3 import android.app.Activity; 4 import android.os.Bundle; 5 6 public class ViewDemoActivity extends Activity { 7 /** Called when the activity is first created. */ 8 @Override 9 public void onCreate(Bundle savedInstanceState) {10 super.onCreate(savedInstanceState);11 MyView mv=new MyView(this);12 setContentView(mv);13 }14 }
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