無法通過NSOutputStream將數據保存到文檔目錄的給定路徑中

Question

如何使用NSOutputStream將下載的內容/數據保存在文檔目錄中的給定路徑中。如果我追加文件名與DD然後它的工作（前DD/contentPath.zip），但如果我追加一個路徑像DD/hello/contentPath.zip那麼它不起作用。爲什麼？我嘗試如下 -

- (void) downloadCarContents:(NSString *)url forContent:(NSString *)contentPath { 

    //NSString *destinationPath = [self.documentDirectory getDownloadContentPath:contentPath]; 

    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager]; 
    AFHTTPRequestOperation *op = [manager GET:url 
            parameters:nil 
             success:^(AFHTTPRequestOperation *operation, id responseObject) { 


             } failure:^(AFHTTPRequestOperation *operation, NSError *error) { 

              //NSLog(@"Error : %@", error.localizedDescription); 
             }]; 

    NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]; 
    NSString *dest = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"hello/%@.zip", contentPath]];// It doesn't work 
    //NSString *dest = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.zip", contentPath]];// It works 

    op.outputStream = [NSOutputStream outputStreamToFileAtPath:dest append:NO]; 

    [op setDownloadProgressBlock:^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead) { 
     float percentage = (float) (totalBytesRead * 100)/totalBytesExpectedToRead; 
     [self.delegate downloadProgression:percentage]; 
    }]; 
} 

Answer 1

該API不會爲您創建文件夾。在您嘗試使用它之前，您的代碼需要確保它存在。 NSFileManager可以幫助createDirectoryAtPath:withIntermediateDirectories:attributes:error: