android 判断手机中是否有SD卡，USB.静态判断

Android 判断SD卡是否存在及容量查询的简单方法如下： 要在AndroidManifest.xml中增加SD卡访问权限<!-- 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"/>调用java代码 private boolean ExistSDCard() { if (android.os.Environment.getExternalStorageState().equals( android.os.Environment.MEDIA_MOUNTED)) { return true; } else return false; } 返回true 表示可用,false表示不可用3.查看SD卡的剩余空间public long getSDFreeSize(){ //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(); //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 //return (freeBlocks * blockSize)/1024; //单位KB return (freeBlocks * blockSize)/1024 /1024; //单位MB }4.查看SD卡总容量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 //return (allBlocks * blockSize)/1024; //单位KB return (allBlocks * blockSize)/1024/1024; //单位MB }