android刮刮奖效果

android刮刮奖效果

自定义View盖在textView上

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

public class EraseView extends View {

private boolean isMove = false;
private Bitmap bitmap = null;
private Bitmap frontBitmap = null;
private Path path;
private Canvas mCanvas;
private Paint paint;


public EraseView(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
protected void onDraw(Canvas canvas) {

if (mCanvas == null) {
EraseBitmp();
}
canvas.drawBitmap(bitmap, 0, 0, null);
mCanvas.drawPath(path,paint);
super.onDraw(canvas);
}

public void EraseBitmp() {

bitmap = Bitmap.createBitmap(getWidth(),getHeight(), Bitmap.Config.ARGB_4444);

frontBitmap = CreateBitmap(Color.GRAY,getWidth(),getHeight());

paint = new Paint();
paint.setStyle(Paint.Style.STROKE);
paint.setXfermode(new PorterDuffXfermode(Mode.CLEAR));
paint.setAntiAlias(true);
paint.setDither(true);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeCap(Paint.Cap.ROUND);
paint.setStrokeWidth(20);

path = new Path();

mCanvas = new Canvas(bitmap);
mCanvas.drawBitmap(frontBitmap, 0, 0,null);
}

@Override
public boolean onTouchEvent(MotionEvent event) {
float ax = event.getX();
float ay = event.getY();

if (event.getAction() == MotionEvent.ACTION_DOWN) {
isMove = false;
path.reset();
path.moveTo(ax, ay);
invalidate();
return true;
} else if (event.getAction() == MotionEvent.ACTION_MOVE) {
isMove = true;
path.lineTo(ax,ay);
invalidate();
return true;
}
return super.onTouchEvent(event);
}

public Bitmap CreateBitmap(int color,int width, int height) {
int[] rgb = new int [width * height];

for (int i=0;i<rgb.length;i++) {
rgb[i] = color;
}

return Bitmap.createBitmap(rgb, width, height,Config.ARGB_8888);
}

}

布局文件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="30dp"
android:layout_marginTop="100dp" >

<TextView
android:id="@+id/tv_main_msg"
android:layout_width="300dp"
android:layout_height="150dp"
android:background="@android:color/holo_red_dark"
android:gravity="center_vertical|center_horizontal"
android:text="你没中奖"
android:textSize="40sp" />

<com.example.guale.EraseView
android:id="@+id/eraseView1"
android:layout_width="300dp"
android:layout_height="150dp" />
</RelativeLayout>

</LinearLayout>