android SurfaceView绘制 重新学习--基础绘制

自从大二写了个android游戏去参加比赛，之后就一直写应用，一直没用过SurfaceView了，现在进入了游戏公司，准备从基础开始重新快速的学一下这个，然后再去研究openGL和游戏引擎。

直接上代码吧：

 import android.content.Context;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.view.SurfaceHolder.Callback;
 import android.view.SurfaceView;
 import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Paint;
 import android.graphics.Typeface;
 import android.view.SurfaceHolder;
 import android.view.animation.Animation;

 public class MySurfaceView extends SurfaceView implements Callback, Runnable {

     private SurfaceHolder sfh;
     private Thread th;
     private Canvas canvas;
     private Paint paint;
     private boolean threadFlag;

     public MySurfaceView(Context context) {
         // this(context, null);

         super(context);
         sfh = this.getHolder();
         sfh.addCallback(this);
         paint = new Paint();
         paint.setAntiAlias(true);
         paint.setColor(Color.RED);
         paint.setTextSize(20);
         Typeface font = Typeface.create(Typeface.SANS_SERIF, Typeface.BOLD);
         paint.setTypeface(font);
         this.setKeepScreenOn(true);
     }

     public MySurfaceView(Context context, AttributeSet attrs) {
         super(context, attrs);
         // th = new Thread(this);
         // sfh = this.getHolder();
         // sfh.addCallback(this);
         // paint = new Paint();
         // paint.setAntiAlias(true);
         // paint.setColor(Color.RED);
         // this.setKeepScreenOn(true);
     }

     public void startAnimation(Animation animation) {
         super.startAnimation(animation);
     }

     public void surfaceCreated(SurfaceHolder holder) {
         threadFlag = true;
         th = new Thread(this);
         th.start();
     }

     private void draw() {
         try {
             canvas = sfh.lockCanvas(); // 获取画布
             if (canvas != null) {
                 canvas.drawColor(Color.WHITE);// 画布颜色
                 canvas.drawText("奋斗的小猿", 100, 100, paint);
                 canvas.drawText("加班，还是不加班，it's a question!", 100, 130, paint);
             }
         } catch (Exception ex) {
         } finally {
             if (canvas != null)
                 sfh.unlockCanvasAndPost(canvas);
         }
     }

     public void run() {
         while (threadFlag) {
             Log.i("ceshi", "threadFlag=true");
             draw();
             try {
                 Thread.sleep(100);
             } catch (InterruptedException e) {
                 e.printStackTrace();
             }
         }
     }

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

     public void surfaceDestroyed(SurfaceHolder holder) {
         threadFlag = false;
     }

 }

这里Activity用的是

setContentView(new MySurfaceView(getApplicationContext()));

如果想在布局中引用：

 <com.tq.listviewtest.MySurfaceView
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:visibility="visible" >
  </com.tq.listviewtest.MySurfaceView>

 setContentView(R.layout.activity_main);

则构造方法应改为：

 public MySurfaceView(Context context) {
         this(context, null);
     }

     public MySurfaceView(Context context, AttributeSet attrs) {
         super(context, attrs);
         sfh = this.getHolder();
         sfh.addCallback(this);
         paint = new Paint();
         paint.setAntiAlias(true);
         paint.setColor(Color.RED);
         paint.setTextSize(20);
         Typeface font = Typeface.create(Typeface.SANS_SERIF, Typeface.BOLD);
         paint.setTypeface(font);
         this.setKeepScreenOn(true);
     }

因为android 加载布局时，只是去执行了第二个构造方法，第一个构造方法没有执行，所以我们要把初始化写在第二个构造方法中了。