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。