Android：BitMap操作相关工具类

package com.example.customalarm.utils;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.BitmapFactory.Options;
import android.graphics.drawable.BitmapDrawable;
import android.os.Handler;
import android.util.DisplayMetrics;
import android.view.WindowManager;

/**
 * CustomUtils工具类
 * 
 * @author BiHaidong
 * @date 2015-11-11
 */
public class CustomUtils {

	/**
	 * 取得屏幕参数（宽高）
	 * 
	 * @param context
	 *            上下文对象
	 * @param options
	 *            BitMap的Options对象
	 * 
	 * @return Object[] {宽，高}
	 * 
	 * @author BiHaidong
	 * @date 2015-11-11
	 */
	@SuppressLint("ServiceCast")
	public static Object[] getScreenParamater(Context context) {

		DisplayMetrics dm = new DisplayMetrics();
		WindowManager manager = (WindowManager) context
				.getSystemService(Context.WINDOW_SERVICE);

		manager.getDefaultDisplay().getMetrics(dm);

		int screenWidth = dm.widthPixels;

		int screenHeight = dm.heightPixels;

		return new Object[] { screenWidth, screenHeight };
	}

	/**
	 * 根据屏幕大小取得压缩比
	 * 
	 * @param context
	 *            上下文对象
	 * @param options
	 *            BitMap的Options对象
	 * 
	 * @author BiHaidong
	 * @date 2015-11-11
	 */
	@SuppressLint("ServiceCast")
	public static int getInSampleSize(Context context, Options options) {

		DisplayMetrics dm = new DisplayMetrics();
		WindowManager manager = (WindowManager) context
				.getSystemService(Context.WINDOW_SERVICE);

		manager.getDefaultDisplay().getMetrics(dm);

		int screenWidth = dm.widthPixels;

		int screenHeight = dm.heightPixels;

		int result = 1;

		if (screenWidth != 0
				&& screenHeight != 0
				&& (options.outWidth > screenWidth || options.outHeight > screenHeight)) {

			result = options.outWidth / screenWidth > options.outHeight
					/ screenHeight ? options.outWidth / screenWidth
					: options.outHeight / screenHeight;

		}

		return result;
	}

	/**
	 * 根据资源文件ID 取得压缩的BitMapDrawable
	 * 
	 * @param context
	 *            上下文对象
	 * @param id
	 *            资源文件ID
	 * @param size
	 *            压缩比例 (100不压缩)
	 * 
	 * @author BiHaidong
	 * @date 2015-11-11
	 */
	public static BitmapDrawable getBitMapDrawable(Context context, int id,
			int size) {

		Bitmap bitmap = CustomUtils.getBitMap(context, id, size);
		return new BitmapDrawable(context.getResources(), bitmap);
	}

	/**
	 * 根据资源文件ID 取得压缩的BitMap
	 * 
	 * @param context
	 *            上下文对象
	 * @param id
	 *            资源文件ID
	 * @param size
	 *            压缩比例 (100不压缩)
	 * 
	 * @author BiHaidong
	 * @date 2015-11-11
	 */
	public static Bitmap getBitMap(Context context, int id, int size) {

		BitmapFactory.Options options = new BitmapFactory.Options();
		options.inJustDecodeBounds = true;
		Bitmap welcomeBitmap = BitmapFactory.decodeResource(
				context.getResources(), id, options);

		int inSampleSize = CustomUtils.getInSampleSize(context, options);

		options.inJustDecodeBounds = false;
		options.inSampleSize = inSampleSize;// 设置缩放比例
		// 重新读入图片，注意此时已经把options.inJustDecodeBounds 设回false了
		welcomeBitmap = BitmapFactory.decodeResource(context.getResources(),
				id, options);
		Bitmap bitmap = compressImage(welcomeBitmap, size);
		welcomeBitmap.recycle();
		return bitmap;
	}

	/**
	 * 取得压缩的BitMap
	 * 
	 * @param image
	 *            BitMap
	 * @param size
	 *            压缩比例 (100不压缩)
	 * 
	 * @author BiHaidong
	 * @date 2015-11-11
	 */
	public static Bitmap compressImage(Bitmap image, int size) {

		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		// 质量压缩方法，这里100表示不压缩，把压缩后的数据存放到baos中
		image.compress(Bitmap.CompressFormat.JPEG, size, baos);
		// 把压缩后的数据baos存放到ByteArrayInputStream中
		ByteArrayInputStream isBm = new ByteArrayInputStream(baos.toByteArray());
		// 把ByteArrayInputStream数据生成图片
		Bitmap bitmap = BitmapFactory.decodeStream(isBm, null, null);
		return bitmap;
	}
}