因为设计原因,需要更改下iOS原生的清除按钮,经过研究可使用rightView方式添加自定义按钮,代码如下

#import <UIKit/UIKit.h>
@interface UITextField (ClearBtn)
@property (nonatomic,strong) UIButton *clearBtn;
@property (nonatomic,strong) UIView *clearView;
- (void)customClearBtnDefaultStyle;
@end

#import<objc/runtime.h>
#import "UITextField+ClearBtn.h"
static const void *clearBtnKey = &clearBtnKey;
static const void *clearViewKey = &clearViewKey;
@implementation UITextField (ClearBtn)
@dynamic clearBtn, clearView;
- (void)customClearBtnDefaultStyle {
  UIButton *clearBtn = [UIButton buttonWithType:UIButtonTypeCustom];
  clearBtn.size = CGSizeMake(14, 14);//肉眼可见的按钮尺寸大小
 [clearBtn setBackgroundImage: (g_nSkinType == tztSkin_White) ? [UIImage imageTztNamed:@"TZTBaseTextFieldClearBG.png"] : [UIImage imageTztNamed:@"zt_black_clear"] forState:UIControlStateNormal];
 [clearBtn addTarget:self action:@selector(clickClearBtn) forControlEvents:UIControlEventTouchUpInside];
 clearBtn.hidden = YES;
 self.clearBtn = clearBtn;

  UIView *clearView = [[UIView alloc]init];
  clearView.size = CGSizeMake(30, 30);//实际按钮尺寸大小,增加用户的点击范围
  [clearView addSubview:clearBtn];
  clearBtn.frameMaxX = clearView.frameMaxX;
 clearBtn.centerY = clearView.centerY;
  clearView.hidden = YES;
  self.clearView = clearView;
  self.rightView = clearView;
  self.rightViewMode = UITextFieldViewModeWhileEditing;

  [self addTarget:self action:@selector(textFieldDidEditing:) forControlEvents:UIControlEventEditingChanged];

  UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(clickClearBtn)];
  [clearView addGestureRecognizer:tap];
}

- (void)setClearBtn:(UIButton *)clearBtn
{
    objc_setAssociatedObject(self, clearBtnKey,clearBtn, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
-(UIButton *)clearBtn
{
    return objc_getAssociatedObject(self,clearBtnKey);
}

- (void)setClearView:(UIView *)clearView
{
    objc_setAssociatedObject(self, clearViewKey,clearView, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
- (UIView *)clearView

    return objc_getAssociatedObject(self,clearViewKey);
}
//清除的时候隐藏
- (void)clickClearBtn {
    self.text = @"";
    self.clearBtn.hidden = YES;
    self.clearView.hidden = YES;
}
//编辑的时候显示按钮
- (void)textFieldDidEditing:(UITextField *)textField {
    self.clearBtn.hidden = NO;
    self.clearView.hidden = NO;
}
@end

使用的时候直接这样调用即可 [passwordTF customClearBtnDefaultStyle];