Android 游戲開發之SurfaceView的簡單使用

    涉及的相關知識點：   1、Callback    一個SurfaceView一定要實現一個SurfaceHolder.Callback接口。以便在底層的Surface狀態發生變化的時候通知View，該接口需要實現以下3個方法：    public void surfaceCreated(SurfaceHolder holder) {}    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height){}    public void surfaceDestroyed(SurfaceHolder holder) {}     2、SurfaceHolder       這是一個用於控制surface的接口，它提供了控制surface 的大小，格式等    SurfaceView的getHolder()函數可以獲取SurfaceHolder對象，Surface 就在SurfaceHolder對象內。         3、具體代碼 MySurfaceView.java  

package cn.llbb.testsurfaceviewdemo;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Rect;
import android.graphics.RectF;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;

public class MySurfaceView extends SurfaceView implements Callback {

private SurfaceHolder sfh;
private Canvas canvas;
private Paint paint;

public MySurfaceView(Context context) {
super(context);
sfh = getHolder();
sfh.addCallback(this);
paint = new Paint();
paint.setColor(Color.RED);
setFocusable(true);
}

public void surfaceCreated(SurfaceHolder holder) {
MyDraw();
}

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

}

public void surfaceDestroyed(SurfaceHolder holder) {

}

private void MyDraw(){
try{
canvas = sfh.lockCanvas();
if(canvas != null){
canvas.drawColor(Color.WHITE);
canvas.drawText("drawtext", 10, 10, paint);

canvas.drawPoint(10, 20, paint);
canvas.drawPoints(new float[]{10,30,30,30}, paint);

canvas.drawLine(10,40,50,40, paint);
canvas.drawLines(new float[]{10,50,50,50,70,50,110,50}, paint);

canvas.drawRect(10,60,40,100, paint);

Rect rect = new Rect(10,110,60,130);
canvas.drawRect(rect, paint);

RectF rectf = new RectF(10,140,60,170);
canvas.drawRoundRect(rectf, 20, 20, paint);

canvas.drawCircle(20, 200, 20, paint);

canvas.drawArc(new RectF(150,20,200,70), 0, 230, true, paint);

canvas.drawOval(new RectF(150,80,180,100), paint);

Path path = new Path();
path.moveTo(160,150);
path.lineTo(200,150);
path.lineTo(180,200);
path.close();
canvas.drawPath(path, paint);

Path pathcircle = new Path();
pathcircle.addCircle(130, 260, 20, Path.Direction.CCW);
canvas.drawTextOnPath("pathtext", pathcircle, 10, 20, paint);

}
}catch(Exception e){

}finally{
sfh.unlockCanvasAndPost(canvas);
}

}
}


MainActivity.java

package cn.llbb.testcanvasdemo;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.Window;
import android.view.WindowManager;

public class MainActivity extends Activity {

protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
//getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(new MySurfaceView(this));

}

}