Objective-C 保存和加载文件

Question

您好，我正在尝试从文件加载数据

此函数将数据保存到文档文件夹中的文件

- (IBAction)saveUser:(id)sender{
   NSString *name = [nameField stringValue];
   NSString *weight = [weightField stringValue];
   NSDate *date = [datePick dateValue];

   NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
   NSString *documentsDirectory = [paths objectAtIndex:0];

   NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];
   [dict setValue:[nameField stringValue] forKey:@"name"];
   [dict setValue:[weightField stringValue] forKey:@"weight"];
   [dict setValue:date forKey:@"date"];
   [dict writeToFile:name atomically:YES];
}

但是，当我尝试加载文件并从中获取数据时，我无法，有人可以告诉我这是如何完成的。

<小时/>

编辑以显示 loadFunction

-(IBAction)loadUser:(id)sender{
 NSString *weight = [weightField stringValue];
 NSDate *date = [datePick dateValue];

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *loadPath = [documentsDirectory stringByAppendingPathComponent:name];

NSMutableDictionary *savedData = [[NSMutableDictionary alloc] initWithContentsOfFile: name]; 
 NSLog(@"%@", weight);
}

Answer 1

修正你的答案。这是一个有效的代码，您几乎没有给出文件名。

NSString *filename = [documentsDirectory stringByAppendingPathComponent:@"file.txt"];

在您写入文件的行中:

[dict writeToFile:name atomically:YES];

您必须将名称更改为文件名，如下所示

[dict writeToFile:filename atomically:YES];

在您的加载数据方法中:

NSString *filename = [documentsDirectory stringByAppendingPathComponent:@"file.txt"];

NSMutableDictionary *savedData = [[NSMutableDictionary alloc] initWithContentsOfFile:filename]; 

NSLog(@"The weight is : %@", [savedData valueForKey:@"weight"]);