UITextField textColor在resignFirstResponder之后恢复

Question

我有一个控制UITextField的textColor的UIButton,我发现当我在UITextField上调用resignFirstResponder时,文本字段是第一个响应者时对textColor所做的任何更改都会丢失,并且颜色会恢复到之前的状态becomeFirstResponder.我正在寻找的行为是textColor应该保留为文本字段是第一响应者时选择的任何内容.

这是相关代码:

- (void)viewDidLoad {
    [super viewDidLoad];

    self.tf = [[UITextField alloc] initWithFrame:CGRectMake(0.0f, 120.0f, self.view.bounds.size.width, 70.0f)];
    self.tf.delegate = self;
    self.tf.text = @"black";
    self.tf.font = [UIFont fontWithName:@"AvenirNext-DemiBold" size:48.0f];
    self.tf.textColor = [UIColor blackColor];
    [self.view addSubview:self.tf];
    self.tf.textAlignment = UITextAlignmentCenter;

    UIButton *b = [[UIButton alloc] initWithFrame:CGRectMake(0.0f, 220.0f, self.view.bounds.size.width, 20.0f)];
    [b addTarget:self action:@selector(changeColor:) forControlEvents:UIControlEventTouchUpInside];
    [b setTitle:@"Change color" forState:UIControlStateNormal];
    [b setTitleColor:[UIColor lightGrayColor] forState:UIControlStateNormal];
    [self.view addSubview:b];
}

- (void)changeColor:(UIButton *)button {
    if ([self.tf.textColor isEqual:[UIColor blackColor]]) {
        self.tf.text = @"red";
        self.tf.textColor = [UIColor redColor];
    } else {
        self.tf.text = @"black";
        self.tf.textColor = [UIColor blackColor];
    }
}

- (BOOL)textFieldShouldReturn:(UITextField *)textField {
    [textField resignFirstResponder];
    return YES;
}

更具体地说,该行为由以下操作产生:

1. UITextField*tf最初为黑色.
2. 点击tf成为FirstResponder.
3. 点击UIButton*b,tf.textColor变为红色(文本也变为@"red",尽管这不是必需的).
4. 点击键盘返回resignFirstResponder,tf.textColor恢复为黑色(文本保持为@"红色").

类似地,如果初始textColor为红色,则textField将恢复为红色.

我创建了一个示例项目,其中只包含产生此行为所需的功能(此处提供).提前致谢.

Answer 1

作为解决方法,您可以在按下按钮时将所选颜色存储在属性上并执行以下操作:

- (BOOL)textFieldShouldReturn:(UITextField *)textField {
    [textField resignFirstResponder];
    textField.textColor = self.selectedColor;
    return YES;
}

UPDATE

正如评论中所指出的,放置此解决方案的更好的地方似乎是textFieldDidEndEditing因为它处理字段之间的跳转:

- (void)textFieldDidEndEditing:(UITextField *)textField {
    textField.textColor = self.selectedColor;
}