最近写了一个项目，遇到需要处理键盘弹出/收起时，避免键盘遮挡输入框的问题。
所以当时我写了一个BaseViewController框架（可以用来当做所有ViewController的基类），在BaseViewController设置属性判断是否需要处理键盘，并且处理了当键盘第一次弹出时会出现中文键盘高度不对的问题。

github地址：https://github.com/WalkingToTheDistant/KeyboardHandle/tree/master，如果觉得我写的代码对你有帮助的话，给我一个星呗^ _ ^

使用方法

设置基类BaseViewController或者其子类的属性isNeedHandleKeyboard为YES（默认NO），这个变量必须在BaseViewController的ViewDidLoad执行之前设置，因为在BaseViewController的ViewDidLoad里面会执行检索代码，给所有输入框添加键盘关闭栏。

/** 是否需要处理键盘弹出/收起的事件，默认NO */
@property(nonatomic, assign) BOOL isNeedHandleKeyboard;

代码解析

首先是添加监听，这里的逻辑，就是用_isNeedHandleKeyboard来判断这个ViewController是否需要处理键盘


@interface BaseViewController ()

/** 是否需要处理键盘弹出/收起的事件，默认NO */
@property(nonatomic, assign) BOOL isNeedHandleKeyboard;

/** 键盘弹出时，需要移动的高度值 */
@property(nonatomic, assign) int moveValueForKeyboard;

@end
- (void) viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    
    if(_isNeedHandleKeyboard == YES){ // 添加键盘监听
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleKeyboardShow:) name:UIKeyboardWillShowNotification object:nil];
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleKeyboardHide:) name:UIKeyboardWillHideNotification object:nil];
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleKeyboardFrameChange:) name:UIKeyboardWillChangeFrameNotification object:nil]; // 监听键盘尺寸的变化
    }
}

- (void) viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    
    if(_isNeedHandleKeyboard == YES){ // 消除键盘监听
        [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
        [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
        [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillChangeFrameNotification object:nil];
    }
}

接下来处理键盘弹出/收起的事件

// ****************************************************************************************************
// ****************************************************************************************************
#pragma mark - 键盘处理
- (void) handleKeyboardShow:(NSNotification*) notification
{
    if(_moveValueForKeyboard > 0){ // 键盘已经处理过，避免在键盘输入的时候再点击了其他的输入框
        return;
    }
    
    CGRect keyboardFrame = [[[notification userInfo] valueForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
    const float duration = [[[notification userInfo] valueForKey:UIKeyboardAnimationDurationUserInfoKey] floatValue];
    const UIViewAnimationOptions options = [[[notification userInfo] valueForKey:UIKeyboardAnimationCurveUserInfoKey] integerValue];
    
    UIView *viewFirst = [[self class] getFirstResponder:self.view];
    if(viewFirst != nil){
        
        CGPoint pointView = [viewFirst convertPoint:self.view.bounds.origin toView:self.view];
        pointView.y += CGRectGetHeight(viewFirst.frame);
        _keyboardHeight = CGRectGetHeight(keyboardFrame);
        int originYForKeyboard = CGRectGetMaxY(self.view.frame) - _keyboardHeight;
        
        if(pointView.y >= originYForKeyboard){ 
            // 输入框被键盘遮挡
            _moveValueForKeyboard = pointView.y - originYForKeyboard;
            __block CGRect frame = self.view.frame;
            frame.origin.y -= _moveValueForKeyboard;
            
            [UIView animateWithDuration:duration delay:0 options:options animations:^{
                self.view.frame = frame;
            } completion:nil];
        } else {
            _moveValueForKeyboard = 0;
        }
    }
}
- (void) handleKeyboardHide:(NSNotification*)notification
{
    if(_moveValueForKeyboard > 0){
        const float duration = [[[notification userInfo] valueForKey:UIKeyboardAnimationDurationUserInfoKey] floatValue];
        const UIViewAnimationOptions options = [[[notification userInfo] valueForKey:UIKeyboardAnimationCurveUserInfoKey] integerValue];
        
        __block CGRect frame = self.view.frame;
        frame.origin.y += _moveValueForKeyboard;
        _moveValueForKeyboard = 0;
        
        [UIView animateWithDuration:duration delay:0 options:options animations:^{
            self.view.frame = frame;
        } completion:nil];
    }
}
- (void) handleKeyboardFrameChange:(NSNotification*)notification
{
    /* 在这里处理中文键盘的高度变化问题，在第一次弹出键盘之后，键盘上随后会展现中文的智能检测栏，导致键盘的高度会变高，而在UIKeyboardWillShowNotification得到的高度缺不包含这个监测栏的高度，从而输入框位置会被键盘遮挡。所以需要在这里监听键盘尺寸的变化，然后再计算尺寸变化值并修改输入框的位置。*/
    CGRect keyboardFrame = [[[notification userInfo] valueForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
    if(_moveValueForKeyboard > 0){ // 需要处理中文键盘的尺寸变化问题
        int valueChange = CGRectGetHeight(keyboardFrame) - _keyboardHeight;
        if(valueChange != 0){
            const float duration = [[[notification userInfo] valueForKey:UIKeyboardAnimationDurationUserInfoKey] floatValue];
            const UIViewAnimationOptions options = [[[notification userInfo] valueForKey:UIKeyboardAnimationCurveUserInfoKey] integerValue];
            __block CGRect frame = self.view.frame;
            frame.origin.y -= valueChange;
            _moveValueForKeyboard += valueChange;
            _keyboardHeight = CGRectGetHeight(keyboardFrame);
            [UIView animateWithDuration:duration delay:0 options:options animations:^{
                self.view.frame = frame;
            } completion:nil];
        }
        
    }
}

这些事件处理需要一个方法辅助，一个是获取当前键盘输入的控件，然后再获取其相对屏幕的坐标，用以判断它是否被键盘给遮挡了

/** 获取当前键盘输入的控件 */
+ (UIView*) getFirstResponder:(UIView*)superView
{
    if(superView.isFirstResponder == YES){
        return superView;
    }
    
    for(UIView *viewChild in superView.subviews){
        if([viewChild isFirstResponder] == YES){
            return viewChild;
        }
    }
    // 再搜索下一层Subview
    for(UIView *viewChild in superView.subviews){
        UIView *viewResult = [[self class] getFirstResponder:viewChild];
        if(viewResult != nil){
            return viewResult;
        }
    }
    return nil;
}

在键盘上方添加关闭栏的通用方法。

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    if(_isNeedHandleKeyboard == YES){
        [self addDoneKeyboardViewToInputView:self.view];
    }
}
/** 创建键盘关闭的View */
+ (UIView*) getKeyboardHideViewWithTarget:(id)target withSelector:(SEL)selector
{
    UIView *viewResult = [[UIView alloc] initWithFrame:CGRectMake(0, 0, CGRectGetWidth(UIScreen.mainScreen.bounds), 40)];
    [viewResult setBackgroundColor:RGBColor(250, 250, 250)];
    
    int height = CGRectGetHeight(viewResult.frame);
    int width = 80;
    int x = CGRectGetMaxX(viewResult.frame) - width;
    int y = 0;
    UIButton *btnDone = [UIButton buttonWithType:UIButtonTypeSystem];
    [btnDone setTitle:@"完成" forState:UIControlStateNormal];
    [btnDone.titleLabel setFont:Font_Bold(16.0f)];
    [btnDone setFrame:CGRectMake(x, y, width, height)];
    [btnDone addTarget:target action:selector forControlEvents:UIControlEventTouchUpInside];
    [viewResult addSubview:btnDone];
    
    return viewResult;
}
/** 给所有输入框的键盘都添加关闭 */
- (void) addDoneKeyboardViewToInputView:(UIView*) superView
{
    //这个方法可能是有效率问题，因为需要遍历整个ViewController的view，暂时还想不到更好的方法
    for(UIView *viewChlid in [superView subviews]){
        if([viewChlid isKindOfClass:[UITextField class]] == YES){
            if([viewChlid inputAccessoryView] == nil){
                UIView *viewDone = [[self class] getKeyboardHideViewWithTarget:self withSelector:@selector(closeKeyboard)];
                [((UITextField*)viewChlid) setInputAccessoryView:viewDone];
            }
            
        } else if([viewChlid isKindOfClass:[UITextView class]] == YES){
            if([viewChlid inputAccessoryView] == nil){
                UIView *viewDone = [[self class] getKeyboardHideViewWithTarget:self withSelector:@selector(closeKeyboard)];
                [((UITextView*)viewChlid) setInputAccessoryView:viewDone];
            }
        } else {
            [self addDoneKeyboardViewToInputView:viewChlid];
        }
    }
}
/** 关闭ViewController的键盘 */
- (void) closeKeyboard
{
    [self.view endEditing:YES];
}

iOS 处理键盘弹出的通用框架BaseViewController

iOS 处理键盘弹出的通用框架BaseViewController

使用方法

代码解析