仿写一款比较流行的短信验证页面,整理出下面一段非常有意思的代码.
虽然只是一个简单的页面,反复调整自认为比较OK.当然实现办法和思路不唯一,希望有兴趣的小伙伴一起品评.

Untitled.gif

用了一个 textField 和四个 label 控件
用了 textfield 的一个代理方法

Untitled2.gif

代码只有一个系统代理方法

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    if ([string isEqualToString:@""]){// 判断删除操作
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.01 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
            NSLog(@"%@",textField.text);
            NSLog(@"%@",string);
            if ([string isEqualToString:@""]){// 判断删除操作
                if (textField.text. length == 0)_message1.text = string;
                if (textField.text.length == 1)_message2.text = string;
                if (textField.text.length == 2)_message3.text = string;
                if (textField.text.length == 3)_message4.text = string;
                
            }else {
                if (textField.text.length == 1)_message1.text = string;
                if (textField.text.length == 2)_message2.text = string;
                if (textField.text.length == 3)_message3.text = string;
                if (textField.text.length == 4)_message4.text = string;}});
        NSLog(@"%@",textField.text);
        NSLog(@"%@",string);
        return 1;
    }else {if (textField.text.length == 4)return 0;}
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.01 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        if ([string isEqualToString:@""]){// 判断删除操作
            if (textField.text.length == 0)_message1.text = string;
            if (textField.text.length == 1)_message2.text = string;
            if (textField.text.length == 2)_message3.text = string;
            if (textField.text.length == 3)_message4.text = string;
        }else {
            
            if (textField.text.length == 1)_message1.text = string;
            if (textField.text.length == 2)_message2.text = string;
            if (textField.text.length == 3)_message3.text = string;
            if (textField.text.length == 4)_message4.text = string;
        }
    });
    if ([string isEqualToString:@""]){// 判断删除操作
        return 1;
    }else {
        if (textField.text.length == 4)return 0;
    }
    return 1;
}

属性

@interface MKReginsterMessageController () <UITextFieldDelegate>
@property (weak, nonatomic) IBOutlet UITextField *messageTextField;
@property (weak, nonatomic) IBOutlet UILabel *message1;
@property (weak, nonatomic) IBOutlet UILabel *message2;
@property (weak, nonatomic) IBOutlet UILabel *message3;
@property (weak, nonatomic) IBOutlet UILabel *message4;
@end

小操作

textfield 的 tintcolor 设为 clear
textfield 的 textcolor 设为 clear

最后只要验证 textfield.text 文本就可以了.