Logic in writing is as follows:

 File File=new File (Environment. GetExternalStoragePublicDirectory (" "), the webView, getTitle () + "test. MHT"); 
//the File File=new File ("/storage/self ", the webView getTitle () + "test. MHT"); 
WebView. SaveWebArchive (file. GetAbsolutePath ()); 

After click on the control error is as follows:
D/a WebView: saveWebArchive=/storage/emulated/0/Swift profile test. The MHT
E/chromium: [ERROR: mhtml_generation_manager. Cc (465)] Failed to create a file to save MHTML at:/storage/emulated/0/Swift profile test. The MHT
E/chromium: [ERROR: mhtml_generation_manager. Cc (479)] Failed to create the file

Read and write access is given, the test machine is 6.0, no sd card and tried to catch exceptions, the Environment of several properties method to obtain different paths, are based on the content of the error, still hope bosses give solutions, very grateful