iOS开发知识点3——键盘

2015-11-17

iOS开发知识点3——键盘

点击屏幕回收键盘是很简单的，但是在scrollView上点击回收键盘，直接调用那个方法就不能实现了

// 我的实现是这样的
// 首先实现一个继承自UIScrollView的Category，.m文件的实现
#import "UIScrollView+UITouch.h"

@implementation UIScrollView (UITouch)

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    [[self nextResponder] touchesBegan:touches withEvent:event];
    [super touchesBegan:touches withEvent:event];
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    [[self nextResponder] touchesMoved:touches withEvent:event];
    [super touchesMoved:touches withEvent:event];
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    [[self nextResponder] touchesEnded:touches withEvent:event];
    [super touchesEnded:touches withEvent:event];
}

// 然后在要回收键盘的界面，导入这个类
#import "UIScrollView+UITouch.h"

// 在touchesBegan方法里，得到要释放的textField，调用resignFirstResponder方法
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    MKInputPhoneNumberCell *inputPhoneNumberCell = (MKInputPhoneNumberCell *)[self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0]];
    [inputPhoneNumberCell.inputPhoneNumberTF resignFirstResponder];
    
    MKPhoneCertifyTableViewCell *phoneCertifyCell = (MKPhoneCertifyTableViewCell *)[self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:1 inSection:0]];
    [phoneCertifyCell.inputCertifyTF resignFirstResponder];
}
@end

当键盘弹出时，有可能会遮盖住输入框，之前我采用把View放到scrollView上来处理，但是后来发现，让View跟着键盘动起来效果更好

// 首先注册通知，弹出键盘和键盘回收两个
// 弹出键盘时view向上偏移，避免遮盖输入框
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];

// 然后实现通知的方法
#pragma mark - keyboard notification -
- (void)keyboardWillShow:(NSNotification *)note {
    NSDictionary *info = [note userInfo];
    // keyboardHeight 为键盘高度
    CGSize keyboardSize = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;
    [self animateViewWithKeyboardHeight: keyboardSize.height];
}

- (void)keyboardWillHide:(NSNotification *)note {
    [self animateViewWithKeyboardHeight: 0.0];
}

- (void)animateViewWithKeyboardHeight:(CGFloat)keyboardHeight
{
    NSTimeInterval animationDuration = 0.3f;
    CGFloat width = self.bounds.size.width;
    CGFloat height = self.bounds.size.height;
    // 保持键盘和输入框底部view至少有-10的间距，这里的间距自己来定
    CGFloat space = -10;
    CGFloat topSize = 0.0;
    CGFloat viewH = _bottomBackView.frame.size.height + _bottomBackView.frame.origin.y + space; // 得到view底部的y
    CGFloat deviceH = self.bounds.size.height;
    // 屏幕高度 - （view底部的y + 键盘的高度）, 如果>=0，则说明距离足够，设置view.origin.y = 0；否则则说明view需要上移
    CGFloat animateH = deviceH - viewH - keyboardHeight;
    if (animateH >= 0) {
        topSize = 0;
        CGRect toRect = CGRectMake(0, topSize, width, height);
        self.frame = toRect;
    } else {
        topSize = animateH;
        CGRect toRect = CGRectMake(0, topSize, width, height);
        [UIView animateWithDuration:animationDuration animations:^{
            self.frame = toRect;
        }];
    }
}

// 最后注销通知
- (void)dealloc {
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
}