无法将NSDictionary写入plist文件

更新：当我更改以下行时，我可以写入文件

[infoDict setObject:userList forKey:@"users"]; 

至

 [infoDict setObject:@"sampleString" forKey:@"users"]; 

所以，我试图写入文件的结构一定有问题，有什么想法？

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我正在尝试创build一个plist文件，并在运行时在我的iOS应用程序中写入。 我不能写信给它，但我可以阅读。 writeToFile方法返回一个“NO”。 当我手动尝试手动打开我使用Finder创build的文件时，它会显示“无法读取数据，因为它的格式不正确”，这是因为在使用文本编辑器打开文件时，它是空，并且不显示plisttypes的文件应该具有的任何xml标签。 而且我知道我可以从中读取，因为在手动拖动文件夹中的“有效”plist文件时，我的代码能够从那里读取一个空列表。

1）为什么不创build一个有效的plist文件？

和，

2）为什么我不能写（甚至是有效的）plist文件？

  NSLog(@"* Writing contents to plist file *"); NSString* path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]; NSString* plistPath = nil; if ((plistPath = [path stringByAppendingPathComponent:@"users.plist"])) { NSFileManager *fileManager = [NSFileManager defaultManager]; BOOL exists = [fileManager fileExistsAtPath:plistPath]; NSLog(exists ? @"yes, file exists": @"no, file doesnt exist"); if (!exists) { NSLog(@"creating file since it doesnt exist"); [fileManager createFileAtPath:plistPath contents:nil attributes:nil]; } NSLog(@"path of file: %@", plistPath); NSMutableDictionary *infoDict = [[NSMutableDictionary alloc] init]; NSLog(@"infoDict: %@", infoDict); [infoDict setObject:userList forKey:@"users"]; NSLog(@"infoDict: %@", infoDict); BOOL wrote = [infoDict writeToFile:plistPath atomically:YES]; NSLog(wrote ? @"yes, wrote to the file": @"no, didn't write to file"); } NSLog(@"--------------------------------------------"); 

以下是控制台中的输出：

  2014-10-17 10:50:11.290 UserReggy[1228:10032] * Writing contents to plist file * 2014-10-17 10:50:11.291 UserReggy[1228:10032] yes, file exists 2014-10-17 10:50:11.291 UserReggy[1228:10032] path of file: /Users/rvyas1/Library/Developer/CoreSimulator/Devices/DB612284-F481-467A-BAE8-37750497F42A/data/Containers/Data/Application/C9620C4D-EF1F-4C17-8D28-4E9B3B41F2C2/Documents/users.plist 2014-10-17 10:50:11.291 UserReggy[1228:10032] infoDict: { } 2014-10-17 10:50:11.291 UserReggy[1228:10032] infoDict: { users = { dfgdfgd = "<User: 0x7ffd884da820>"; }; } 2014-10-17 10:50:11.292 UserReggy[1228:10032] no, didn't write to file 2014-10-17 10:50:11.294 UserReggy[1228:10032] -------------------------------------------- 

Answer 1

您可以在userList中检查您的数据，它必须是NSMutableDictionary Reference中的属性列表对象（NSData，NSDate，NSNumber，NSString，NSArray或NSDictionary的实例），doc

Answer 2

问题是在行NSMutableDictionary *infoDict = [NSMutableDictionary dictionaryWithContentsOfFile:plistPath];

它会给你null对象，因为你的plistPath是零

Answer 3

 NSMutableDictionary *fileData; NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [paths objectAtIndex:0]; NSString *path = [documentsDirectory stringByAppendingPathComponent:@"data.plist"]; NSFileManager *fileManager = [NSFileManager defaultManager]; if ([fileManager fileExistsAtPath: path]) { fileData = [[NSMutableDictionary alloc] init]; if ([fileData initWithContentsOfFile: path]) { fileData = [fileData initWithContentsOfFile: path]; } } else { [fileManager createFileAtPath:path contents:nil attributes:nil]; fileData = [[NSMutableDictionary alloc] initWithCapacity:0]; } [fileData setObject:data forKey:qid]; BOOL wrote = [fileData writeToFile:path atomically:YES]; NSLog(wrote ? @"yes, wrote to the file": @"no, didn't write to file"); 

尝试这个。 为我工作。