ios - 从 NSData 中提取文件名

Question

我正在使用蓝牙将文件发送到其他设备。发送的内容是 NSData：

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *documentsDirectoryPath = [paths objectAtIndex:0];
NSString *myFilePath = [documentsDirectoryPath stringByAppendingPathComponent: [NSString stringWithFormat:@"%@.ext", button.titleLabel.text]];

NSData *Recording = [NSData dataWithContentsOfFile:myFilePath];

该文件是一个图像。该文件已收到并且可以正常查看，但我想将其保存到与以前相同的名称的文档目录中，即 button.titleLabel.text。当您发送文件时，它总是有一个名称。我怎么才能得到它？

Answer 1

• Your code

  NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);  
  NSString *documentsDirectoryPath = [paths objectAtIndex:0];  
  NSString *myFilePath = [documentsDirectoryPath stringByAppendingPathComponent: [NSString stringWithFormat:@"%@.ext", button.titleLabel.text]];  
  NSData *Recording = [NSData dataWithContentsOfFile:myFilePath];
  

• Make NSDictionary and put the filename and image data like this

  NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithObjects:myFilePath,Recording  forKeys:@"fileName",@"imageData"];
  

• Then convert the dictionary into NSData like this

  NSData *myData = [NSKeyedArchiver archivedDataWithRootObject:dict];
  

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• After recieving the data convert the data into dictionary again and extract the imageData and the filePath

  NSDictionary *myDictionary = (NSDictionary*) [NSKeyedUnarchiver unarchiveObjectWithData:myData];
  

Answer 2

您需要将文件名作为单独的实体（可能是 NSString 或 NSData）发送，或者，由于它是图像，您可以将文件名添加到 EXIF 数据中，尽管这并不容易。