Android得到SD卡文件夹大小以及删除文件夹操作

float cacheSize = dirSize(new File(Environment.getExternalStorageDirectory() + AppConstants.APP_CACHE_FOLDER)) / 1024.0f / 1024.0f;

tvCacheSize.setText(((int) (cacheSize * 100)) / 100.0f + "M");

/**

* Return the size of a directory in bytes

*/

private long dirSize(File dir) {



if (dir.exists()) {

long result = 0;

File[] fileList = dir.listFiles();

for (int i = 0; i < fileList.length; i++) {

// Recursive call if it's a directory

if (fileList[i].isDirectory()) {

result += dirSize(fileList[i]);

} else {

// Sum the file size in bytes

result += fileList[i].length();

}

}

return result; // return the file size

}

return 0;

}



case R.id.clearCacheLayout:

try {

DeleteRecursive(new File(Environment.getExternalStorageDirectory() + AppConstants.APP_CACHE_FOLDER));

Toast.makeText(mActivity, "缓存已清除", Toast.LENGTH_SHORT).show();

float cacheSize = dirSize(new File(Environment.getExternalStorageDirectory() + AppConstants.APP_CACHE_FOLDER)) / 1024.0f / 1024.0f;

tvCacheSize.setText(((int) (cacheSize * 100)) / 100 + "M");

} catch (Exception e) {

e.printStackTrace();

}

break;





/** 

* 删除某个文件夹下的所有文件夹和文件 

* 

* @param delpath 

*/

private void DeleteRecursive(File fileOrDirectory) {

if (fileOrDirectory.isDirectory())

for (File child : fileOrDirectory.listFiles())

DeleteRecursive(child);



fileOrDirectory.delete();

}

 读取Assets文件内容

//从assets 文件夹中获取文件并读取数据

public String getFromAssets(String fileName){

   String result = "";

   try {

InputStream in = getResources().getAssets().open(fileName);

//获取文件的字节数

int lenght = in.available();

//创建byte数组

byte[]  buffer = new byte[lenght];

//将文件中的数据读到byte数组中

in.read(buffer);

result = EncodingUtils.getString(buffer, ENCODING);

} catch (Exception e) {

e.printStackTrace();

}

return result;

}

}