用android处理图片的时候，由于得到的资源不一样，所以经常要在各种格式中相互转化，以下介绍了 Bitmap Drawable byte[] InputStream 之间的转换方法：

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.InputStream;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.graphics.Canvas;

import android.graphics.PixelFormat;

import android.graphics.drawable.BitmapDrawable;

import android.graphics.drawable.Drawable;  

/**

 * Bitmap与DrawAble与byte[]与InputStream之间的转换工具类

 * @author Administrator

 *

 */

public class FormatTools {

    private static FormatTools tools = new FormatTools();  

    public static FormatTools getInstance() {

        if (tools == null) {

            tools = new FormatTools();

            return tools;

        }

        return tools;

    }  

    // 将byte[]转换成InputStream

    public InputStream Byte2InputStream(byte[] b) {

        ByteArrayInputStream bais = new ByteArrayInputStream(b);

        return bais;

    }  

    // 将InputStream转换成byte[]

    public byte[] InputStream2Bytes(InputStream is) {

        String str = "";

        byte[] readByte = new byte[1024];

        int readCount = -1;

        try {

            while ((readCount = is.read(readByte, 0, 1024)) != -1) {

                str += new String(readByte).trim();

            }

            return str.getBytes();

        } catch (Exception e) {

            e.printStackTrace();

        }

        return null;

    }  

    // 将Bitmap转换成InputStream

    public InputStream Bitmap2InputStream(Bitmap bm) {

        ByteArrayOutputStream baos = new ByteArrayOutputStream();

        bm.compress(Bitmap.CompressFormat.JPEG, 100, baos);

        InputStream is = new ByteArrayInputStream(baos.toByteArray());

        return is;

    }  

    // 将Bitmap转换成InputStream

    public InputStream Bitmap2InputStream(Bitmap bm, int quality) {

        ByteArrayOutputStream baos = new ByteArrayOutputStream();

        bm.compress(Bitmap.CompressFormat.PNG, quality, baos);

        InputStream is = new ByteArrayInputStream(baos.toByteArray());

        return is;

    }  

    // 将InputStream转换成Bitmap

    public Bitmap InputStream2Bitmap(InputStream is) {

        return BitmapFactory.decodeStream(is);

    }  

    // Drawable转换成InputStream

    public InputStream Drawable2InputStream(Drawable d) {

        Bitmap bitmap = this.drawable2Bitmap(d);

        return this.Bitmap2InputStream(bitmap);

    }  

    // InputStream转换成Drawable

    public Drawable InputStream2Drawable(InputStream is) {

        Bitmap bitmap = this.InputStream2Bitmap(is);

        return this.bitmap2Drawable(bitmap);

    }  

    // Drawable转换成byte[]

    public byte[] Drawable2Bytes(Drawable d) {

        Bitmap bitmap = this.drawable2Bitmap(d);

        return this.Bitmap2Bytes(bitmap);

    }  

    // byte[]转换成Drawable

    public Drawable Bytes2Drawable(byte[] b) {

        Bitmap bitmap = this.Bytes2Bitmap(b);

        return this.bitmap2Drawable(bitmap);

    }  

    // Bitmap转换成byte[]

    public byte[] Bitmap2Bytes(Bitmap bm) {

        ByteArrayOutputStream baos = new ByteArrayOutputStream();

        bm.compress(Bitmap.CompressFormat.PNG, 100, baos);

        return baos.toByteArray();

    }  

    // byte[]转换成Bitmap

    public Bitmap Bytes2Bitmap(byte[] b) {

        if (b.length != 0) {

            return BitmapFactory.decodeByteArray(b, 0, b.length);

        }

        return null;

    }  

    // Drawable转换成Bitmap

    public Bitmap drawable2Bitmap(Drawable drawable) {

        Bitmap bitmap = Bitmap

                .createBitmap(

                        drawable.getIntrinsicWidth(),

                        drawable.getIntrinsicHeight(),

                        drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888

                                : Bitmap.Config.RGB_565);

        Canvas canvas = new Canvas(bitmap);

        drawable.setBounds(0, 0, drawable.getIntrinsicWidth(),

                drawable.getIntrinsicHeight());

        drawable.draw(canvas);

        return bitmap;

    }  

    // Bitmap转换成Drawable

    public Drawable bitmap2Drawable(Bitmap bitmap) {

        BitmapDrawable bd = new BitmapDrawable(bitmap);

        Drawable d = (Drawable) bd;

        return d;

    }

}