iOS開發知識點3——鍵盤

iOS 開發知識點 3—— 鍵盤#

點擊螢幕回收鍵盤是很簡單的，但是在 scrollView 上點擊回收鍵盤，直接調用那個方法就不能實現了

// 我的實現是這樣的
// 首先實現一個繼承自UIScrollView的Category，.m檔案的實現
#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];
}

// 然後在要回收鍵盤的界面，導入這個類
#import "UIScrollView+UITouch.h"

// 在touchesBegan方法裡，得到要釋放的textField，調用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

當鍵盤彈出時，有可能會遮蓋住輸入框，之前我採用把 View 放到 scrollView 上來處理，但是後來發現，讓 View 跟著鍵盤動起來效果更好

// 首先註冊通知，彈出鍵盤和鍵盤回收兩個
// 彈出鍵盤時view向上偏移，避免遮蓋輸入框
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];

// 然後實現通知的方法
#pragma mark - keyboard notification -
- (void)keyboardWillShow:(NSNotification *)note {
    NSDictionary *info = [note userInfo];
    // keyboardHeight 為鍵盤高度
    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;
    // 保持鍵盤和輸入框底部view至少有-10的間距，這裡的間距自己來定
    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;
    // 螢幕高度 - （view底部的y + 鍵盤的高度）, 如果>=0，則說明距離足夠，設定view.origin.y = 0；否則則說明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;
        }];
    }
}

// 最後註銷通知
- (void)dealloc {
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
}