ios - 委托文本字段并将其限制为仅输入数字

Question

我正在以编程方式创建一些UITextFields，当我尝试委派它们时，我收到以下警告：

NAVPlanViewController *const __strong' 到不兼容类型的参数id<UITextFieldDelegate>

textHeight = [[UITextField alloc] initWithFrame:CGRectMake(0, 120, 160, 40)];
[textHeight setDelegate:self];

在.c我的课堂上，我添加了@interface NAVPlanViewController : UIViewController <UITextViewDelegate>. 另外，我需要限制文本字段只接受数字，我想用这段代码来做，但因为我UITextField无法Delegate检查它：

- (BOOL)textField:(UITextField *)textField 
        shouldChangeCharactersInRange:(NSRange)range 
                    replacementString:(NSString *)string {

    if (!string.length) {
            return YES;
    }

    if ([string rangeOfCharacterFromSet:[[NSCharacterSet decimalDigitCharacterSet] 
                                         invertedSet]].location != NSNotFound){
        //do something;
        return NO;
    }

Answer 1

在您的NAVPlanViewController接口定义中，<UITextViewDelegate>应该是<UITextFieldDelegate>.

Answer 2

@neilco 是正确的符合喜欢

@interface YourViewController ()<UITextFieldDelegate>
{

}
@end

并且除了数字，将keyboardType设置为UIKeyboardTypeNumberPad，如

UITextField *age = [UITextField autolayoutView];
age.placeholder = kPlaceholderToEnterAge;
age.borderStyle = UITextBorderStyleRoundedRect;
age.clearButtonMode = UITextFieldViewModeWhileEditing;
age.returnKeyType = UIReturnKeyDefault;
age.keyboardType = UIKeyboardTypeNumberPad;
age.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
age.textAlignment = NSTextAlignmentCenter;