setValue：forKey：使用NSString

Question

I'm currently working on a small and specific iPhone app to connect to a server and download some JSON data. My problem is about a property list I use to save some data (login, password and domain of the server). I've easily created the plist in Xcode but when I try to edit it with the texts entered by the user, I'm having a problem and I don't know how to fix it ...

Here is the textFieldDidEndEditing: method , in which I try to write to the plist, with what the user have written in a domainTextField :

- (void)textFieldDidEndEditing:(UITextField *)textField
{

    NSArray *paths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *filepath = [NSString stringWithFormat:@"%@/userInfo.plist", [paths objectAtIndex:0]];
    NSMutableDictionary *userInfo = [[NSMutableDictionary alloc] initWithContentsOfFile:filepath];

    if (self.domainTextField) {
        NSString *domain = [NSString stringWithFormat:@"%@", self.domainTextField.text];
        [userInfo setValue:domain forKey:@"domain"];
    }

    if ([userInfo writeToFile:filepath atomically:TRUE]) {
        NSLog(@"write succeeded");
    } else {
        NSLog(@"write failed");
    }
}

I'm always receiving a "write failed" error here and after playing a bit with the debugger, I found that the problem is with the setValue:forKey: method . In fact, I expect this method to write that in the plist : domain = "whateverthedomainis" because domain is a NSString but it writes instead : domain = whateverthedomainis . And as the writeToFile:atomically: method makes sure that all the objects are property list objects, it returns NO. I tried to put backslashes, but that didn't help.

What can I do to resolve this error?

Answer 1

如果字符串中有任何参数，将使用StringWithFormat，这样您就可以直接分配一个字符串值，就像这样

NSString *domain = self.domainTextField.text;