android小应用帮美女更衣系列二（附源码）

[color=violet]点击ImageSwitcher显示的图片即可切换到为美女换衣全屏界面，手指在界面上滑动，滑动处的衣服就被褪掉了，很黄很暴力，大家要hold住呀！！[/color]
[color=red]其实啊这个实现就是两张图片，一张底图，一张上面的图，上面的图都被抹掉了，下面的图就出来了，主要是PorterDuff和PorterDuffXfermode的利用，APIDEMO里面也有相关的介绍。好，贴出主要代码:
[/color]

package com.picture;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;

public class RemoveClothActivity extends Activity {

	private int SCREEN_W;

	private int SCREEN_H;

	private int imagePosition;

	private MediaPlayer mp3Player;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);//设置全屏
		Intent intent = getIntent();
		imagePosition = intent.getIntExtra("imagePosition", 0);
		initMP3Player();
		setContentView(new MyView(this));
	}

	private void initMP3Player(){
		mp3Player = MediaPlayer.create(RemoveClothActivity.this, R.raw.higirl);
		mp3Player.setLooping(false);
	}

	private void playMusic(){
		mp3Player.start();
	}

	class MyView extends View {
		private Bitmap mBitmap;
		private Canvas mCanvas;
		private Paint mPaint;
		private Path mPath;
		private float mX, mY;
		private static final float TOUCH_TOLERANCE = 4;

		public MyView(Context context) {
			super(context);
			setFocusable(true);
			setScreenWH();
			setBackGround();

			// 1.if icon1 is a image,you can open MENU_ITEM_COMMENT bellow
			// Bitmap bm = createBitmapFromSRC();
			// if you want to set icon1 image's alpha,you can open
			// MENU_ITEM_COMMENT bellow
			// bm = setBitmapAlpha(bm, 100);
			// if you want to scale icon1 image,you can open MENU_ITEM_COMMENT
			// bellow
			// bm = scaleBitmapFillScreen(bm);

			// 2.if icon1 is color
			// Bitmap bm = createBitmapFromARGB(0x8800ff00, SCREEN_W, SCREEN_H);
			int drawableId = 0;
			try {
				drawableId = R.drawable.class.getDeclaredField(
						"pre" + imagePosition).getInt(this);
			} catch (IllegalArgumentException e) {
				e.printStackTrace();
			} catch (SecurityException e) {
				e.printStackTrace();
			} catch (IllegalAccessException e) {
				e.printStackTrace();
			} catch (NoSuchFieldException e) {
				e.printStackTrace();
			}
			Bitmap bm = scaleBitmapFillScreen(BitmapFactory.decodeResource(getResources(), drawableId));
			seticon1Bitmap(bm);

		}

		private void setScreenWH() {
			// get screen info
			DisplayMetrics dm = new DisplayMetrics();
			dm = this.getResources().getDisplayMetrics();
			// get screen width
			int screenWidth = dm.widthPixels;
			// get screen height
			int screenHeight = dm.heightPixels;

			SCREEN_W = screenWidth;
			SCREEN_H = screenHeight;
		}

		private Bitmap createBitmapFromSRC() {
			return BitmapFactory.decodeResource(getResources(),
					R.drawable.icon1);
		}

		/**
		 * 
		 * @param colorARGB
		 *            should like 0x8800ff00
		 * @param width
		 * @param height
		 * @return
		 */
		private Bitmap createBitmapFromARGB(int colorARGB, int width, int height) {
			int[] argb = new int[width * height];

			for (int i = 0; i < argb.length; i++) {

				argb[i] = colorARGB;

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

		/**
		 * 
		 * @param bm
		 * @param alpha
		 *            ,and alpha should be like ox00000000-oxff000000
		 * @note set bitmap's alpha
		 * @return
		 */
		/*
		 * private Bitmap setBitmapAlpha(Bitmap bm, int alpha) { int[] argb =
		 * new int[bm.getWidth() * bm.getHeight()]; bm.getPixels(argb, 0,
		 * bm.getWidth(), 0, 0, bm.getWidth(), bm .getHeight());
		 * 
		 * 
		 * for (int i = 0; i < argb.length; i++) {
		 * 
		 * argb[i] = ((alpha) | (argb[i] & 0x00FFFFFF)); } return
		 * Bitmap.createBitmap(argb, bm.getWidth(), bm.getHeight(),
		 * Config.ARGB_8888); }
		 */

		/**
		 * 
		 * @param bm
		 * @param alpha
		 *            ,alpha should be between 0 and 255
		 * @note set bitmap's alpha
		 * @return
		 */
		private Bitmap setBitmapAlpha(Bitmap bm, int alpha) {
			int[] argb = new int[bm.getWidth() * bm.getHeight()];
			bm.getPixels(argb, 0, bm.getWidth(), 0, 0, bm.getWidth(),
					bm.getHeight());

			for (int i = 0; i < argb.length; i++) {

				argb[i] = ((alpha << 24) | (argb[i] & 0x00FFFFFF));
			}
			return Bitmap.createBitmap(argb, bm.getWidth(), bm.getHeight(),
					Config.ARGB_8888);
		}

		/**
		 * 
		 * @param bm
		 * @note if bitmap is smaller than screen, you can scale it fill the
		 *       screen.
		 * @return
		 */
		private Bitmap scaleBitmapFillScreen(Bitmap bm) {
			return Bitmap.createScaledBitmap(bm, SCREEN_W, SCREEN_H, true);
		}

		private void setBackGround(){
			int drawableId = 0;
			try {
				drawableId = R.drawable.class.getDeclaredField(
						"after" + imagePosition).getInt(this);
			} catch (IllegalArgumentException e) {
				e.printStackTrace();
			} catch (SecurityException e) {
				e.printStackTrace();
			} catch (IllegalAccessException e) {
				e.printStackTrace();
			} catch (NoSuchFieldException e) {
				e.printStackTrace();
			}
			setBackgroundResource(drawableId);
		}

		/**
		 * 
		 * @param bm
		 * @note set icon1 bitmap , which overlay on background.
		 */
		private void seticon1Bitmap(Bitmap bm) {
			// setting paint
			mPaint = new Paint();
			mPaint.setAlpha(0);
			mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
			mPaint.setAntiAlias(true);

			mPaint.setDither(true);
			mPaint.setStyle(Paint.Style.STROKE);
			mPaint.setStrokeJoin(Paint.Join.ROUND);
			mPaint.setStrokeCap(Paint.Cap.ROUND);
			mPaint.setStrokeWidth(20);

			// set path
			mPath = new Path();
			;

			// converting bitmap into mutable bitmap
			mBitmap = Bitmap.createBitmap(SCREEN_W, SCREEN_H, Config.ARGB_8888);
			mCanvas = new Canvas();
			mCanvas.setBitmap(mBitmap);
			// drawXY will result on that Bitmap
			// be sure parameter is bm, not mBitmap
			mCanvas.drawBitmap(bm, 0, 0, null);
		}

		@Override
		protected void onDraw(Canvas canvas) {
			canvas.drawBitmap(mBitmap, 0, 0, null);
			mCanvas.drawPath(mPath, mPaint);
			super.onDraw(canvas);
		}

		private void touch_start(float x, float y) {
			mPath.reset();
			mPath.moveTo(x, y);
			mX = x;
			mY = y;
		}

		private void touch_move(float x, float y) {
			float dx = Math.abs(x - mX);
			float dy = Math.abs(y - mY);
			if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
				mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
				mX = x;
				mY = y;
			}
		}

		private void touch_up() {
			mPath.lineTo(mX, mY);
			// commit the path to our offscreen
			mCanvas.drawPath(mPath, mPaint);
			// kill this so we don't double draw
			mPath.reset();
		}

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

			switch (event.getAction()) {
			case MotionEvent.ACTION_DOWN:
				touch_start(x, y);
				invalidate();
				break;
			case MotionEvent.ACTION_MOVE:
				touch_move(x, y);
				invalidate();
				break;
			case MotionEvent.ACTION_UP:
				touch_up();
				invalidate();
				playMusic();
				break;
			}
			return true;
		}
	}
}