android storage sdcard1,Android，没有备份到extern sd卡（/ storage/sdcard1 /）

SD卡可能尚未准备好。在写入之前，请考虑等待外部存储器准备就绪，如下所示。

// Wait till external storage is initialized upon startup.

private void awaitExternalStorageInitialization() {

boolean mExternalStorageAvailable = false;

boolean mExternalStorageWriteable = false;

int count = 0;

do {

String state = Environment.getExternalStorageState();

if(count > 0) {

try {

Thread.sleep(3000);

} catch (InterruptedException e) {

Logger.log(e.getMessage(), Logger.LogType.ERROR, e);

}

}

if (Environment.MEDIA_MOUNTED.equals(state)) {

// We can read and write the media

mExternalStorageAvailable = mExternalStorageWriteable = true;

} else if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {

// We can only read the media

mExternalStorageAvailable = true;

mExternalStorageWriteable = false;

} else {

// Something else is wrong. It may be one of many other states,

// but all we need to know is we can neither read nor write

mExternalStorageAvailable = mExternalStorageWriteable = false;

}

count++;

} while ((!mExternalStorageAvailable) && (!mExternalStorageWriteable)

&& (count < 15));

if(!mExternalStorageWriteable)

Logger.log("External storage not ready yet", Logger.LogType.ERROR, null);

}