寫入臨時目錄不起作用

Question

我正在嘗試將文件寫入臨時目錄。我這樣做：

NSString *_location = NSTemporaryDirectory(); 
NSString *_guid = [[NSCalendarDate calendarDate] descriptionWithCalendarFormat:@"%m%d%Y%H%M%S%F"]; 
_guid = [_guid stringByAppendingString:@".png"]; 
NSString *_tempFilePath = [NSString stringWithFormat:@"%@/%@", _location, _guid]; 
NSData *_temp_data = [imgRep representationUsingType: NSPNGFileType properties: nil]; 
[_temp_data writeToFile:_tempFilePath atomically: NO]; 

但它不適用於我。它不創建文件。有什麼問題？

P.S.我試圖在NSTemporaryDirectory中創建一個具有唯一名稱的目錄，然後在那裏寫入一個文件，但它也不起作用。

---

我注意到它不會在任何地方創建文件。試圖將位置設置爲用戶的文檔文件夾，但它不工作。

Answer 1

路徑用於寫入圖像是不正確的：

NSString *_tempFilePath = [NSString stringWithFormat:@"%@/%@", _location,_guid]; 

OR

NSString *_tempFilePath = [location stringByAppendingPathComponent:@"%@",guid]; 

Answer 2

如果你寫裏面潛在的新目錄中的文件，你必須先創建目錄：

[[NSFileManager defaultManager] createDirectoryAtPath:_directoryPath 
          withIntermediateDirectories:YES 
              attributes:nil error:nil]; 

[_myData writeToFile:[_directoryPath stringByAppendingPathComponent:_fileName] 
      atomically:YES];