SurfaceView

画板清空

package com.example.day1113_demo;

import android.annotation.SuppressLint;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity implements SurfaceHolder.Callback {

    private Button clear;
    private SurfaceView sv;
   
    private SurfaceHolder holder;

    private Path path;

    private Paint paint;//畫筆
    private Canvas canvas;//画布

    @SuppressLint("ClickableViewAccessibility")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        clear = (Button) findViewById(R.id.clear);
        sv = (SurfaceView) findViewById(R.id.sv);
       


        path = new Path();
        holder  = sv.getHolder();
        holder.addCallback(this);
        sv.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                int action = event.getAction();
                float x = event.getX();
                float y = event.getY();
                if (action == MotionEvent.ACTION_DOWN){
                    path.moveTo(x,y);
                }
                if (action == MotionEvent.ACTION_MOVE){
                    path.lineTo(x,y);
                }
                return true;
            }
        });

        //清空
        clear.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                path.reset();
            }
        });

    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        new MyThread().start();
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {

    }
    class MyThread extends Thread{
        @Override
        public void run() {
            super.run();
             paint = new Paint();

            paint.setColor(Color.BLUE);
            paint.setStyle(Paint.Style.STROKE);//空心
            paint.setStrokeWidth(20);
            paint.setTextSize(20);
            while (true){
                 canvas = holder.lockCanvas();
                if (canvas == null){
                    break;
                }
                canvas.drawColor(Color.WHITE);
                canvas.drawPath(path,paint);
                holder.unlockCanvasAndPost(canvas);
            }

        }
    }
}

画一张图片(飞机大战部分)

package com.example.app2;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Toast;

import com.example.app2.Bean.ZhujueBean;

public class MainActivity extends AppCompatActivity implements SurfaceHolder.Callback {

    private static final String TAG = "zzzzzzz";
    private SurfaceView sv;
    private SurfaceHolder holder;
    private ZhujueBean zhujueBean;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        sv = (SurfaceView) findViewById(R.id.sv);
        holder = sv.getHolder();
        holder.addCallback(this);
        sv.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                return true;
            }
        });

        int kuan = getWindowManager().getDefaultDisplay().getWidth();
        int gao = getWindowManager().getDefaultDisplay().getHeight();
        Toast.makeText(this, kuan+"+++"+gao, Toast.LENGTH_SHORT).show();
        zhujueBean = new ZhujueBean(R.drawable.zhujue,500,1200);

    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        new MyThread().start();
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {

    }
    class MyThread extends Thread{
        @Override
        public void run() {
            super.run();
            Paint paint = new Paint();
                Canvas canvas = holder.lockCanvas();
                canvas.drawColor(Color.WHITE);
                Bitmap bitmap = BitmapFactory.decodeResource(getResources(), zhujueBean.img);
                Log.i(TAG, zhujueBean.x+"++++"+zhujueBean.y);
                canvas.drawBitmap(bitmap,zhujueBean.x,zhujueBean.y,paint);
                holder.unlockCanvasAndPost(canvas);
        }
    }
}