参考资料：
Android游戏编程之从零开始
涉及的相关知识点：
1、Callback
一个SurfaceView一定要实现一个SurfaceHolder.Callback接口。以便在底层的Surface状态发生变化的时候通知View，该接口需要实现以下3个方法：
public void surfaceCreated(SurfaceHolder holder) {}
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height){}
public void surfaceDestroyed(SurfaceHolder holder) {}
2、SurfaceHolder
这是一个用于控制surface的接口，它提供了控制surface 的大小，格式等
SurfaceView的getHolder()函数可以获取SurfaceHolder对象，Surface 就在SurfaceHolder对象内。
3、具体代码 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));
}
}
效果图:
