Android编程之判断SD卡状态的方法

<!-- 在SDCard 的挂载权限 --><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"/>

import java.io.File; import android.os.Environment; import android.os.StatFs; public class SDTool {   private static SDTool tool = null;   // 检查SD卡是否挂载   public boolean SD_EXIST = false;   private SDTool() {   }   public static SDTool instance() {     if (tool == null) {       synchronized (SDTool.class) {         if (tool == null) {           tool = new SDTool();           tool.SD_EXIST = Environment.MEDIA_MOUNTED               .equals(Environment.getExternalStorageState());         }       }     }     return tool;   }   public long getSDFreeSize() {     // 取得SD卡文件路径     File path = Environment.getExternalStorageDirectory();     StatFs sf = new StatFs(path.getPath());     long blockSize = sf.getBlockSize();     // 空闲的数据块的数量     long freeBlocks = sf.getAvailableBlocks();     // 返回SD卡空闲大小     return freeBlocks * blockSize; // 单位Byte   }   public long getSDAllSize() {     // 取得SD卡文件路径     File path = Environment.getExternalStorageDirectory();     StatFs sf = new StatFs(path.getPath());     // 获取单个数据块的大小(Byte)     long blockSize = sf.getBlockSize();     // 获取所有数据块数     long allBlocks = sf.getBlockCount();     // 返回SD卡大小     return allBlocks * blockSize; // 单位Byte   } }