iOS 点击背景自动隐藏键盘

UITextField+HideKeyBoard.h

#import <UIKit/UIKit.h>
@interface UITextField (HideKeyBoard)
-(void)hideKeyBoard:(UIView *)view;
@end

UITextField+HideKeyBoard.m

#import "UITextField+HideKeyBoard.h"

@implementation UITextField (HideKeyBoard)
- (void) hideKeyBoard:(UIView*)view{
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] 
                                   initWithTarget:self 
                                   action:@selector(doHideKeyBoard)];
    
    tap.numberOfTapsRequired = 1;
    [view  addGestureRecognizer: tap];
    [tap setCancelsTouchesInView:NO];
    [tap release];
}

- (void)doHideKeyBoard{
    [self resignFirstResponder];
} 
@end

YouViewController.m

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    [self.txtValue hideKeyBoard:self.view];
}

[self.fm_username hideKeyBoard:self.view];

[self.fm_password hideKeyBoard:self.view];

当使用两次以后,只有最后一次生效,前面的都是无效的.