自定义TextField的删除按钮

#import <UIKit/UIKit.h>

@interface CustomTextField : UITextField

@property(strong,nonatomic)NSString * alwaysShowStr;

@end

@interface CustomTextField ()

{

    UIButton * _button;

}

@end

@implementation CustomTextField

- (id)initWithFrame:(CGRect)frame

{

    self = [super initWithFrame:frame];

    if (self) {

        // Initialization code

    }

    return self;

}

- (void)drawRect:(CGRect)rect

{

    // Drawing code

    self.layer.borderWidth = 1.0;

    self.layer.borderColor = [UIColor lightGrayColor].CGColor;

    UIView * view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 5, 20)];

    self.leftView = view;

    self.leftViewMode = UITextFieldViewModeAlways;

    _button = [UIButton buttonWithType:UIButtonTypeCustom];

    _button.frame = CGRectMake(0, 0, 40, 40);

    [_button addTarget:self action:@selector(deleteSelfText) forControlEvents:UIControlEventTouchUpInside];

    [_button setImage:[UIImage imageNamed:@"delete.png"] forState:UIControlStateNormal];

    _button.imageEdgeInsets = UIEdgeInsetsMake(13,18,13,8);

    UIView * rightView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 40, 40)];

    [rightView addSubview:_button];

    self.rightView = rightView;

    self.rightViewMode = UITextFieldViewModeAlways;

    _button.hidden = YES;

    [self addTarget:self action:@selector(textHadLength) forControlEvents:UIControlEventAllEvents];

}

-(void)deleteSelfText{    

    self.text = _alwaysShowStr;

    if (!_alwaysShowStr) {

         _button.hidden = YES;

    }

}

-(void)textHadLength

{

    if (self.text.length>=1) {

        _button.hidden = NO;

    }else{

        _button.hidden = YES;

    }

 　if (!self.editing) {

        _button.hidden = YES;

    }

}

-(CGRect)rightViewRectForBounds:(CGRect)bounds

{

    return CGRectMake(self.width-40, 0, 40, 40);

}

/*

// Only override drawRect: if you perform custom drawing.

// An empty implementation adversely affects performance during animation.

- (void)drawRect:(CGRect)rect

{

    // Drawing code

}

*/

@end