11_SurfaceView绘图

　　学习SurfaceView绘图API的使用方法，为接下来使用SurfaceView开发游戏做准备。

package com.example.surfaceview;

import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new MyView(this));

    }

}

package com.example.surfaceview;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class MyView extends SurfaceView implements SurfaceHolder.Callback {

    private Paint paint = null;

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

    // 一定要锁定画布和解锁画布
    public void draw() {
        Canvas canvas = getHolder().lockCanvas();
        canvas.drawColor(Color.WHITE);
        canvas.drawRect(0, 0, 100, 100, paint);

        getHolder().unlockCanvasAndPost(canvas);

    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        draw();
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width,
            int height) {
        // TODO Auto-generated method stub

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        // TODO Auto-generated method stub

    }

}