iOS TextFiled、TextView 关于键盘的收起以及处理键盘遮挡

        在iOS开发中，UITextFiled和UITextView是很常见的两个控件，当我们设置好这两个控件后，点击文字输入区域，系统会自动弹出键盘，但是如何收起键盘、点击哪里收起键盘，以及在iPhone4中键盘弹出后遮挡输入框怎么办呢？

这篇文章将带领大家解决：

1》点击其他空白区域收起键盘

2》点击键盘右下角的键收起键盘

3》处理键盘遮挡问题

一，点击其他空白区域收起键盘

- (void)viewDidLoad {
    [super viewDidLoad];

    [self setUpForDismissKeyboard];    
}

#pragma mark - 回收任何空白区域键盘事件
- (void)setUpForDismissKeyboard {
    NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
    UITapGestureRecognizer *singleTapGR =
    [[UITapGestureRecognizer alloc] initWithTarget:self
                                            action:@selector(tapAnywhereToDismissKeyboard:)];
    NSOperationQueue *mainQuene =[NSOperationQueue mainQueue];
    [nc addObserverForName:UIKeyboardWillShowNotification
                    object:nil
                     queue:mainQuene
                usingBlock:^(NSNotification *note){
                    [self.view addGestureRecognizer:singleTapGR];
                }];
    [nc addObserverForName:UIKeyboardWillHideNotification
                    object:nil
                     queue:mainQuene
                usingBlock:^(NSNotification *note){
                    [self.view removeGestureRecognizer:singleTapGR];
                }];
}

- (void)tapAnywhereToDismissKeyboard:(UIGestureRecognizer *)gestureRecognizer {
    //此method会将self.view里所有的subview的first responder都resign掉
    [self.view endEditing:YES];
}

二，点击键盘右下角的键收起键盘

#pragma mark - TextView 代理方法

-(BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
    if ([text isEqualToString:@"\n"]) {
        
        [self.workLogTextView resignFirstResponder];
        
        return NO;
    }
    
    return YES;
}

注意：需要遵守textView/textFiled的代理。改代码是textView代理方法，若实际用到的是textFiled，只需调用textFiled的该类方法即可。

三，处理键盘遮挡问题

#pragma mark 键盘遮挡
- (BOOL)textViewShouldBeginEditing:(UITextView *)textView {
    if (self.userInfo.isPhone4) {
        CGFloat offset_y = 0.f;
        if (textView.tag == CALL_CONTENT_TEXTFIRLD) {
            offset_y = 100.f;
        }
        CGPoint point = self.BackScrollView.contentOffset;
        point = CGPointMake(point.x, offset_y);
        [UIView animateWithDuration:0.25 animations:^{
            self.BackScrollView.contentOffset = point;
        }];
    }
    return YES;
}


- (BOOL)textViewShouldEndEditing:(UITextView *)textView{
    if (self.userInfo.isPhone4) {
        CGFloat offset_y = 0.f;
        if (textView.tag == CALL_CONTENT_TEXTFIRLD) {
            offset_y = 100.f;
        }
        CGPoint point = self.BackScrollView.contentOffset;
        point = CGPointMake(point.x, 0);
        [UIView animateWithDuration:0.25 animations:^{
            self.BackScrollView.contentOffset = point;
        }];
    }
    return YES;
}

注意：需要遵守 UIScrollViewDelegate 和 textView/textFiled的代理。需要该页面的父视图是UIScrollView，才能保证弹出键盘时页面向上移动，收起键盘时页面向下移动。代码中的self.BackScrollView就是对应的父视图，使用时请替换掉。