Android:Surface以及Canvas高速繪圖(利用Canvas繪製Bitmap)

兩個矩形不斷作變化

package com.example.mysurfacetest;

import ....

public class MainActivity extends Activity {

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

//將主程式畫面設給繼承SurfaceView的自建內部類別

setContentView(new MySurface(this));

}

//自建內部類別必須繼承SurfaceView以及實作SurfaceHolder.Callback

//並實作其抽象Callback方法

public class MySurface extends SurfaceView implements

SurfaceHolder.Callback {

//建立以及宣告Handler來管理以及調派執行緒

final private Handler handler = new Handler();

//宣告SurfaceHolder，之後用來取得Canvas物件

SurfaceHolder holder;

boolean flag;

//宣告畫筆變數以及建立物件

Paint mPaint = new Paint();

               //建構式

public MySurface(Context context) {

super(context);

// TODO Auto-generated constructor stub

//取得SurfaceHolder物件

holder = this.getHolder();

//addCallback()設定callback函式

holder.addCallback(this);

flag = true;

}

//繪圖的工作在自建執行緒t中執行

Thread t = new Thread(new Runnable() {

public void run() {

// TODO Auto-generated method stub

drawPicture();

}

});

               //Callback

public void surfaceChanged(SurfaceHolder holder, int format, int width,

int height) {

// TODO Auto-generated method stub

}

                //Callback

public void surfaceCreated(SurfaceHolder holder) {

// TODO Auto-generated method stub

//啟動執行緒

t.start();

}

                 //Callback

public void surfaceDestroyed(SurfaceHolder holder) {

// TODO Auto-generated method stub

handler.removeCallbacks(t);

}

protected void drawPicture() {

// TODO Auto-generated method stub

// Bitmap bitmap=BitmapFactory.decodeResource(getResources(),R.drawable.ic_launcher);

                        //鎖定畫布，並利用SurfaceHolder取得canvas物件

Canvas c = holder.lockCanvas();

if (flag) {

mPaint.setColor(Color.RED);

// c.drawBitmap(bitmap, bitmap.getWidth(), bitmap.getHeight(), null);

//用Canvas繪圖

//RectF(原點X軸,原點Y軸,寬,高)

c.drawRect(new RectF(0, 100, 1200, 600), mPaint);

flag = false;

} else {

mPaint.setColor(Color.BLUE);

c.drawRect(new RectF(380, 380, 760, 760), mPaint);

flag = true;

}

//解鎖畫布

holder.unlockCanvasAndPost(c);

//執行緒t暫停1秒後再跑一次

handler.postDelayed(t, 1000);

}

}

}