目录：

1、使用SurfaceView画一张图

2、自定义view绘制一张图

开始认真学一下Android多媒体开发，拓宽多媒体的技术面，绘制一张图在Android中有三种方法：SurfaceView、ImageView、自定义View。

1、使用SurfaceView画一张图

package com.example.tongjiangsong.surfaceviewdemo; import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Path;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.SurfaceHolder;import android.view.SurfaceView; public class CommonSurfaceView extends SurfaceView implements SurfaceHolder.Callback,Runnable {     private SurfaceHolder mHolder;    private Canvas mCanvas;    private Path mPath;    private Paint mPaint;    //用于绘制的线程    private Thread mThread;    //线程状态的标记(线程的控制开关)    private boolean isRunning;    private int drawX;    private int drawY;     public CommonSurfaceView(Context context) {        this(context,null);    }     public CommonSurfaceView(Context context, AttributeSet attrs) {        this(context, attrs,0);    }     public CommonSurfaceView(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        //初始化        mHolder = getHolder();        mHolder.addCallback(this);//管理生命周期        mPath=new Path();        //初始化画笔        mPaint=new Paint();        mPaint.setStyle(Paint.Style.STROKE);        mPaint.setStrokeWidth(6);        mPaint.setAntiAlias(true);        mPaint.setColor(Color.RED);        setFocusable(true);        setFocusableInTouchMode(true);        this.setKeepScreenOn(true);    }     @Override    public void surfaceCreated(SurfaceHolder holder) {         isRunning = true;        mThread = new Thread(this);        mThread.start();//开启线程    }     @Override    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {    }     @Override    public void surfaceDestroyed(SurfaceHolder holder) {        isRunning = false;    }     /***     * 注意这个是在子线程中绘制的     */    @Override    public void run() {        while (isRunning) {            drawX++;            drawY = (int) (100 * Math.sin(drawX * 2 * Math.PI / 180) + 400);            mPath.lineTo(drawX, drawY);            draw();        }     }     /***     * 注意这个是在子线程中绘制的，surface支持子线程更新ui，所以     */    private void draw() {        Canvas canvas = null;        //给画布加锁，防止线程安全，防止该内存区域被其他线程公用        canvas = mHolder.lockCanvas();        if (null != canvas) {            //清屏操作或者设置背景            canvas.drawColor(Color.WHITE);            canvas.drawPath(mPath, mPaint);            //提交显示视图并解锁，防止长期占用此内存            mHolder.unlockCanvasAndPost(canvas);        }    }  }

输出结果：

2、使用自定义view绘制一张图

package com.example.tongjiangsong.viewdemo;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;import java.util.Random;public class BallView extends View {    private Context mContext;    private AttributeSet mAttrs;    private Paint paint;        //定义画笔    public BallView(Context context) {        super(context);        this.mContext = context;        //初始化画笔        initPaint();    }    public BallView(Context context, AttributeSet attrs) {        super(context, attrs);        this.mContext = context;        this.mAttrs = attrs;        initPaint();    }    public BallView(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        this.mContext = context;        this.mAttrs = attrs;        initPaint();    }    private void initPaint(){        paint = new Paint();    }    //重写onDraw方法实现绘图操作    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        paint.setAntiAlias(false);                       //设置画笔为无锯齿        paint.setColor(Color.BLACK);                    //设置画笔颜色        canvas.drawColor(Color.WHITE);                  //白色背景        paint.setStrokeWidth((float) 3.0);              //线宽        paint.setStyle(Paint.Style.STROKE);                   //空心效果        canvas.drawCircle(50, 50, 10, paint);           //绘制圆形        canvas.drawCircle(100, 100, 20, paint);         //绘制圆形        canvas.drawCircle(150, 150, 30, paint);         //绘制圆形        canvas.drawCircle(200, 200, 40, paint);         //绘制圆形        canvas.drawCircle(250, 250, 50, paint);         //绘制圆形        canvas.drawCircle(300, 300, 60, paint);         //绘制圆形        canvas.drawCircle(350, 350, 70, paint);         //绘制圆形    }}

输出结果：

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本人CSDN博客地址：https://blog.csdn.net/tong5956​​