Question

我有这段代码，用于检查用户是否在用户名和密码文本字段中输入了内容，密码文本字段中的密码与确认密码文本字段中的密码匹配：

- (IBAction)createAccountButton:(id)sender {
    if([self.createPasswordTextField.text isEqualToString:self.confirmPasswordTextField.text] && self.createPasswordTextField.text.length != 0 && self.createUserNameTextField.text.length != 0){
        NSDictionary *userAccountDetails = [[NSDictionary alloc] init];
        [userAccountDetails setValue:self.createUserNameTextField.text forKey:@"username"];
        [userAccountDetails setValue:self.createPasswordTextField forKey:@"password"];
        [[NSUserDefaults standardUserDefaults] setObject:self.users forKey:@"users"];
        [[NSUserDefaults standardUserDefaults] synchronize];
        [self.users addObject:userAccountDetails];
    }else{
        UIAlertView *passwordMismatchAlert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Passwords do not match!" delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:nil];
        [passwordMismatchAlert show];
    }
}

由于某种原因，每次我点击createAccountButton时，我都会在Xcode中收到一条错误：这个类不是密钥值的密码值编码符号。我确保我的IB网点没有被打破，因为很多其他帖子指出了这一点。所以我不确定这种方法发生了什么。有什么见解吗？

Answer 1

您应该使用NSMutableDictionary和setObject:forKey:

 NSMutableDictionary * dic = [[NSMutableDictionary alloc] init];
[dic setObject:yourobj forKey:yourkey];

所以在你的代码中

 NSMutableDictionary *userAccountDetails = [[NSMutableDictionary alloc] init];
[userAccountDetails setObject:self.createUserNameTextField.text forKey:@"username"];
[userAccountDetails setObject:self.createPasswordTextField forKey:@"password"];
[[NSUserDefaults standardUserDefaults] setObject:self.users forKey:@"users"];
[[NSUserDefaults standardUserDefaults] synchronize];
[self.users addObject:userAccountDetails];

Answer 2

您的User类需要实现NSCoding协议https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Protocols/NSCoding_Protocol/

NSDictionary编码兼容

2 个答案: