自定义一个UITextField

• 先上效果图

  
  屏幕快照 2018-08-16 下午3.50.45.png

• WLTextField.h

#import <UIKit/UIKit.h>

@protocol WLTextFieldDelegate<NSObject>

// 获取输入框内的值
-(void)wlTextFieldDidChange:(NSString *)text;

@end

@interface WLTextField : UIView<UITextFieldDelegate>

@property(nonatomic,strong)UIView *underLine; // 下划线

@property(nonatomic,weak)id<WLTextFieldDelegate> delegate;

@end

• WLTextField.m

#import "WLTextField.h"

@implementation WLTextField

-(instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        
        UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, frame.size.width, frame.size.height - 11)];
        textField.placeholder = @"请输入充电桩编号";
        textField.borderStyle = UITextBorderStyleNone;
        textField.delegate = self;
        [textField addTarget:self action:@selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];
        [self addSubview:textField];
        
        _underLine = [[UIView alloc] initWithFrame:CGRectMake(0, frame.size.height - 1, frame.size.width, 1)];
        _underLine.backgroundColor = [UIColor grayColor];
        [self addSubview:_underLine];
        
    }
    return self;
}

#pragma TextField private method
-(void)textFieldDidChange:(UITextField *)textField
{
    if (self.delegate && [self.delegate respondsToSelector:@selector(wlTextFieldDidChange:)]) {
        [self.delegate wlTextFieldDidChange:textField.text];
    }
//    NSLog(@"内容 : %@",textField.text);
}


#pragma UITextFieldDelegate
-(void)textFieldDidBeginEditing:(UITextField *)textField
{
    _underLine.backgroundColor = [UIColor greenColor];
}

-(void)textFieldDidEndEditing:(UITextField *)textField
{
    _underLine.backgroundColor = [UIColor grayColor];
}

-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    // 四位加一个空格
    if ([string isEqualToString:@""]) { // 删除字符
        if ((textField.text.length - 2) % 5 == 0) {
            textField.text = [textField.text substringToIndex:textField.text.length - 1];
        }
    } else {
        if (textField.text.length % 5 == 0) {
            textField.text = [NSString stringWithFormat:@"%@ ", textField.text];
        }
    }
    return YES;
}

• 实现文件 实现代理

WLTextField *textField = [[WLTextField alloc] initWithFrame:CGRectMake(20, 84, 200, 30)];
textField.delegate = self;
[self.view addSubview:textField];

#pragma mark WLTextFieldDelegate
-(void)wlTextFieldDidChange:(NSString *)text
{
    NSLog(@"我的内容 : %@",text);
}