android刮刮卡效果

//自定义控件代码
package com.sutong.feihua.view;  
  
import com.sutong.fangtao.R;  
import com.sutong.feihua.wallet.GuaGua;  
  
import android.annotation.SuppressLint;  
import android.annotation.TargetApi;  
import android.content.Context;  
import android.graphics.Bitmap;  
import android.graphics.Bitmap.Config;  
import android.graphics.Paint.Align;  
import android.graphics.Paint.Style;  
import android.graphics.BitmapFactory;  
import android.graphics.Canvas;  
import android.graphics.Color;  
import android.graphics.Paint;  
import android.graphics.Path;  
import android.graphics.PorterDuff;  
import android.graphics.PorterDuffXfermode;  
import android.graphics.Rect;  
import android.graphics.RectF;  
import android.os.Build;  
import android.os.Handler;  
import android.os.Message;  
import android.support.v4.widget.SlidingPaneLayout.PanelSlideListener;  
import android.util.AttributeSet;  
import android.util.Log;  
import android.view.MotionEvent;  
import android.view.View;  
public class GuaGuaKa extends View  
{  
  
    /** 
     * 绘制线条的Paint,即用户手指绘制Path 
     */  
    private Paint mOutterPaint = new Paint();  
    /** 
     * 记录用户绘制的Path 
     */  
    private Path mPath = new Path();  
    /** 
     * 内存中创建的Canvas 
     */  
    private Canvas mCanvas;  
    /** 
     * mCanvas绘制内容在其上 
     */  
    private Bitmap mBitmap;  
    /** 
     * ------------------------以下是奖区的一些变量 
     */  
    private Bitmap mBackBitmap;  
    private boolean isComplete;  
  
    private Paint mBackPint = new Paint();  
    private Rect mTextBound = new Rect();  
    private String mText = "0";  
  
    private int mLastX;  
    private int mLastY;  
  
    public GuaGuaKa(Context context)  
    {  
        this(context, null);  
    }  
  
    public GuaGuaKa(Context context, AttributeSet attrs)  
    {  
        this(context, attrs, 0);  
    }  
  
    public GuaGuaKa(Context context, AttributeSet attrs, int defStyle)  
    {  
        super(context, attrs, defStyle);  
        init();  
    }  
  
    public void init()  
    {  
        mPath = new Path();  
        mBackBitmap = BitmapFactory.decodeResource(getResources(),  
                 R.drawable.a0m);  
        setUpOutPaint();  
        setUpBackPaint();  
  
    }  
  
    /** 
     * 初始化canvas的绘制用的画笔 
     */  
    private void setUpBackPaint()  
    {  
        mBackPint.setStyle(Style.FILL);  
        mBackPint.setTextScaleX(2f);  
        mBackPint.setColor(Color.DKGRAY);  
        mBackPint.setTextSize(70);  
        mBackPint.getTextBounds(mText, 0, mText.length(), mTextBound);  
    }  
  
    @Override  
    protected void onDraw(Canvas canvas)  
    {  
          
        canvas.drawBitmap(mBackBitmap, 0, 0, null);  
        // 绘制奖项  
//      canvas.drawText(mText, getWidth() / 2 - mTextBound.width() / 2,  
//              getHeight() / 2 + mTextBound.height() / 2, mBackPint);  
        if (!isComplete)  
        {  
            drawPath();  
            canvas.drawBitmap(mBitmap, 0, 0, null);  
        }  
    }  
  
    @TargetApi(Build.VERSION_CODES.KITKAT) @SuppressLint("NewApi") @Override  
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)  
    {  
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);  
  
        int width = getMeasuredWidth();  
        int height = getMeasuredHeight();  
        // 初始化bitmap  
        mBitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);  
        mCanvas = new Canvas(mBitmap);  
  
        // 绘制遮盖层  
        // mCanvas.drawColor(Color.parseColor("#c0c0c0"));  
        mOutterPaint.setStyle(Paint.Style.FILL);  
        //绘制灰色背景  
//      mCanvas.drawRoundRect(new RectF(0, 0, width, height), 30, 30,  
//              mOutterPaint);  
        mCanvas.drawBitmap(BitmapFactory.decodeResource(getResources(),  
                R.drawable.s_title), null, new RectF(0, 0, width, height), null);  
    }  
  
    /** 
     * 设置画笔的一些参数 
     */  
    private void setUpOutPaint()  
    {  
        // 设置画笔  
        // mOutterPaint.setAlpha(0);  
        mOutterPaint.setColor(Color.parseColor("#c0c0c0"));  
        mOutterPaint.setAntiAlias(true);  
        mOutterPaint.setDither(true);  
        mOutterPaint.setStyle(Paint.Style.STROKE);  
        mOutterPaint.setStrokeJoin(Paint.Join.ROUND); // 圆角  
        mOutterPaint.setStrokeCap(Paint.Cap.ROUND); // 圆角  
        // 设置画笔宽度  
        mOutterPaint.setStrokeWidth(50);  
    }  
  
    /** 
     * 绘制线条 
     */  
    private void drawPath()  
    {  
        mOutterPaint.setStyle(Paint.Style.STROKE);  
        mOutterPaint  
                .setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));  
        mCanvas.drawPath(mPath, mOutterPaint);  
    }  
  
    @Override  
    public boolean onTouchEvent(MotionEvent event)  
    {  
        int action = event.getAction();  
        int x = (int) event.getX();  
        int y = (int) event.getY();  
        switch (action)  
        {  
        case MotionEvent.ACTION_DOWN:  
            mLastX = x;  
            mLastY = y;  
            mPath.moveTo(mLastX, mLastY);  
            break;  
        case MotionEvent.ACTION_MOVE:  
  
            int dx = Math.abs(x - mLastX);  
            int dy = Math.abs(y - mLastY);  
  
            if (dx > 3 || dy > 3)  
                mPath.lineTo(x, y);  
  
            mLastX = x;  
            mLastY = y;  
            break;  
        case MotionEvent.ACTION_UP:  
            new Thread(mRunnable).start();  
            break;  
        }  
  
        invalidate();  
        return true;  
    }  
    //设置底部文字  
    public void setTitle(String title)  
    {  
        mText = title;  
    }  
    public void setBlackImg(int id)  
    {  
        mBackBitmap = BitmapFactory.decodeResource(getResources(),  
                 id);  
    }  
    /** 
     * 统计擦除区域任务 
     */  
    private Runnable mRunnable = new Runnable()  
    {  
        private int[] mPixels;  
  
        @Override  
        public void run()  
        {  
  
            int w = getWidth();  
            int h = getHeight();  
  
            float wipeArea = 0;  
            float totalArea = w * h;  
  
            Bitmap bitmap = mBitmap;  
  
            mPixels = new int[w * h];  
  
            /** 
             * 拿到所有的像素信息 
             */  
            bitmap.getPixels(mPixels, 0, w, 0, 0, w, h);  
  
            /** 
             * 遍历统计擦除的区域 
             */  
            for (int i = 0; i < w; i++)  
            {  
                for (int j = 0; j < h; j++)  
                {  
                    int index = i + j * w;  
                    if (mPixels[index] == 0)  
                    {  
                        wipeArea++;  
                    }  
                }  
            }  
  
            /** 
             * 根据所占百分比，进行一些操作 
             */  
            if (wipeArea > 0 && totalArea > 0)  
            {  
                int percent = (int) (wipeArea * 100 / totalArea);  
                Log.e("TAG", percent + "");  
  
                if (percent > 40)  
                {  
                    Log.e("TAG", "清除区域达到70%，下面自动清除");  
                    System.out.println("清除区域达到70%，下面自动清除");  
                    isComplete = true;  
                    postInvalidate();  
                    Message message = new Message();  
                    message.what = 1;  
                    GuaGua.gua.handler.sendMessage(message);  
                }  
            }  
        }  
  
    };  
}  

//xml代码

<com.sutong.feihua.view.GuaGuaKa
    android:id="@+id/guaguaka"
    android:layout_width="290dp"
    android:layout_height="160dp"
    android:layout_gravity="center"
</com.sutong.feihua.view.GuaGuaKa>