Android在6.0有了动态权限管理，在文件创建时就需要动态权限。

Android的API对应版本如下：

首先检查并申请权限：

if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){

int writePermission = checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE);

if(writePermission != PackageManager.PERMISSION_GRANTED){

requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},REQUEST_CODE);

return ;

}

}

申请权限回调：

@Override

public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {

super.onRequestPermissionsResult(requestCode, permissions, grantResults);

if(requestCode == REQUEST_CODE){

if(permissions[0].equals(Manifest.permission.WRITE_EXTERNAL_STORAGE) && grantResults[0] == PackageManager.PERMISSION_GRANTED){

saveFile();

}else{

Toast.makeText(this,"授权失败",Toast.LENGTH_SHORT).show();

}

}

}

保存文件saveFile代码如下：

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

File file = new File(Environment.getExternalStorageDirectory(), "lmlfiletest.txt");

if(file.exists()){

file.delete();

}

try {

FileOutputStream fos = new FileOutputStream(file);

String info = etInfo.getText().toString();

fos.write(info.getBytes("utf-8"));

fos.close();

} catch (Exception e) {

e.printStackTrace();

}

Toast.makeText(this, "创建成功!", Toast.LENGTH_SHORT).show();

}

测试成功！