package com.app21;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.IOException;import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Bitmap.CompressFormat;
import android.util.Base64;
import sun.misc.BASE64Decoder.encoder.BASE64Decoder;
import sun.misc.BASE64Decoder.encoder.BASE64Encoder;public class ImgHelper  {/*** TODO:将byte数组以Base64方式编码为字符串* @param bytes 待编码的byte数组* @return 编码后的字符串* */public static String encode(byte[] bytes){return new BASE64Encoder().encode(bytes);}/*** TODO:将以Base64方式编码的字符串解码为byte数组* @param encodeStr 待解码的字符串* @return 解码后的byte数组* @throws IOException * */public static byte[] decode(String encodeStr) throws IOException{byte[] bt = null;  BASE64Decoder decoder = new BASE64Decoder();  bt = decoder.decodeBuffer(encodeStr);return bt;}/*** TODO:将两个byte数组连接起来后，返回连接后的Byte数组* @param front 拼接后在前面的数组* @param after 拼接后在后面的数组* @return 拼接后的数组* */public static byte[] connectBytes(byte[] front, byte[] after){byte[] result = new byte[front.length + after.length];System.arraycopy(front, 0, result, 0, after.length);System.arraycopy(after, 0, result, front.length, after.length);return result;}/*** TODO:将图片以Base64方式编码为字符串* @param imgUrl 图片的绝对路径（例如：D:\\jsontest\\abc.jpg）* @return 编码后的字符串* @throws IOException * */public static String encodeImage(String imgUrl) throws IOException{FileInputStream fis = new FileInputStream(imgUrl);byte[] rs = new byte[fis.available()];fis.read(rs);fis.close();return encode(rs);}/*** 将Bitmap转换成字符串* @param bitmap* @return*/public static String bitmaptoString(Bitmap bitmap) {String string = null;ByteArrayOutputStream bStream = new ByteArrayOutputStream();bitmap.compress(CompressFormat.PNG, 100, bStream);byte[] bytes = bStream.toByteArray();string = Base64.encodeToString(bytes, Base64.DEFAULT);return string;}/*** 把byte数组转化成 bitmap对象* @param b* @return*/public static Bitmap bytes2Bimap(byte[] b) {if (b.length != 0) {return BitmapFactory.decodeByteArray(b, 0, b.length);} else {return null;}}
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:id="@+id/container"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"tools:context="com.app21.MainActivity"tools:ignore="MergeRootFrame" ><Buttonandroid:id="@+id/bt"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="点击到Sd卡文件界面内" /><ImageViewandroid:id="@+id/image1"android:layout_width="100dp"android:layout_height="100dp" /></LinearLayout>

package com.app21;
import java.io.IOException;
import java.io.InputStream;import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;/*** @author admin* 对drawable里面的图片进行存取*/
public class MainActivity extends Activity {ImageView imageView1 ;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main );imageView1 = (ImageView) findViewById( R.id.image1 ) ;//得到bitmap流字符串String bitmapString = ImgHelper.bitmaptoString( getBitmap() ) ;try {Bitmap bitmap = ImgHelper.bytes2Bimap( ImgHelper.decode( bitmapString )) ;imageView1.setImageBitmap( bitmap ) ;} catch (IOException e) {e.printStackTrace();}Button button = (Button) findViewById( R.id.bt ) ;button.setOnClickListener( new OnClickListener() {@Overridepublic void onClick(View v) {startActivity( new Intent( MainActivity.this , MainActivityFile.class ));}});}//得到bitmappublic Bitmap getBitmap(){InputStream inputStream = getResources().openRawResource(R.drawable.ic_launcher );  BitmapDrawable drawable = new BitmapDrawable(inputStream);  Bitmap bitmap = drawable.getBitmap();  return bitmap ;}
}

 1 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     xmlns:tools="http://schemas.android.com/tools"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:orientation="vertical"
 6     tools:ignore="MergeRootFrame" >
 7
 8     <ImageView
 9         android:id="@+id/image_file"
10         android:layout_width="wrap_content"
11         android:layout_height="wrap_content" />
12
13 </LinearLayout>

package com.app21;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.widget.ImageView;public class MainActivityFile extends Activity {ImageView imageView1 ;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_file  );imageView1 = (ImageView) findViewById( R.id.image_file ) ;String str  ;//将图片转化为字符串try {str = ImgHelper.encodeImage( getFileName() );Bitmap bitmap = ImgHelper.bytes2Bimap( ImgHelper.decode( str )) ;imageView1.setImageBitmap( bitmap ) ;} catch (IOException e) {e.printStackTrace();}}/*** 把图片存到本地* @return sd卡图片的路径*/String getFileName(){Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.libingbing  );File SpicyDirectory = new File("/sdcard/Images/");SpicyDirectory.mkdirs(); String filename="/sdcard/Images/" + "test11111" + ".jpg";FileOutputStream out = null ;try {out = new FileOutputStream(filename);bmp.compress(Bitmap.CompressFormat.JPEG , 100 , out);}catch (Exception e) {e.printStackTrace();}finally{try {out.flush();}catch (IOException e){e.printStackTrace();}}try {out.close();} catch (IOException e){e.printStackTrace();}out=null;return filename ;}
}

    <!-- 在SDCard中创建与删除文件权限 -->    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />    <!-- 往SDCard写入数据权限 -->    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />    <!-- 从SDCard读取数据权限 -->    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />