示例图：

MyView.java：

package com.example.demo;import android.content.Context;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.View;import com.example.myoomtest.R;public class MyView extends View {public MyView(Context context) {super(context);}@Overrideprotected void onDraw(Canvas canvas) {
//        super.onDraw(canvas);//画笔Paint paint = new Paint();paint.setColor(Color.RED);//设置画笔的风格，如 Style.FILL（实心）、// Style.FILL_AND_STROKE（同时显示实心和空心）或 Style.STROKE（空心）。paint.setStyle(Paint.Style.FILL);//设置空心 边框 宽度paint.setStrokeWidth(20.0f);//在画布上画条线/**** xxxxxxY 000000Y 000000Y 000000* */canvas.drawLine(0,50,500,50,paint);//画一条直线canvas.drawLine(100,0,100,200,paint);//画一条竖线canvas.drawLine(300,0,600,200,paint);//画一条斜线Paint paint2 = new Paint();paint2.setStyle(Paint.Style.STROKE);//（空心）paint2.setStrokeWidth(10);//边框大小paint2.setARGB(100,120,255,100);/*** 画矩形 rect* */canvas.drawRect(100,300,300,500,paint2);Paint paint3 = new Paint();paint3.setStyle(Paint.Style.STROKE);//（空心）paint3.setStrokeWidth(10);//边框线大小paint3.setARGB(100,120,255,100);/*** x , y  位置* 圆的 半径* 画圆形 circle* */canvas.drawCircle(600f,600f,60f,paint3);canvas.drawCircle(700f,700f,60f,paint);/**画文字* 基准线* */Paint paint4 = new Paint();paint4.setARGB(100,120,255,0);paint4.setTextSize(200);//文字大小paint4.setStrokeWidth(10);//边框线大小//基准线canvas.drawLine(0,1000,1000,1000,paint4);canvas.drawText("appblmqq",20,1000,paint4);/*** 绘制图片到画布* */Paint paint6 = new Paint();canvas.drawBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.kk),200,1200,paint6);}}

MainActivity.java

public class MainActivity extends AppCompatActivity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);
//        setContentView(R.layout.activity_main);setContentView(new MyView(this));}}