如果文件已经存在并且您尝试写入文件会发生什么？

Question

它会不会写入或写入失败？

NSData * pdfData = [[NSData alloc] initWithData:[PDFImageConverter convertImageToPDF: [image image]]];
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString * filename = sharedManager.localFileName; //file name already exists
    NSString *pdfPath = [documentsDirectory stringByAppendingPathComponent:filename];
    [pdfData writeToFile:pdfPath atomically:YES];
    [pdfData release];

Answer 1

如果写成功,它将被覆盖.请注意,如果atomically设置为YES,则写入失败时原始文件不会被损坏.如果atomically设置为NO,它将.