前言

再iOS的开发中，很多时候我们都需要解决TextField的键盘遮挡事件，每次都需要花时间，我们可以使用第三方库来解决，但第三方库很多代码质量参差不齐，而且代码量庞大。本文来分享一个代码量比较小的，有关键注释并且使用简单的JVTextField，你也可以依葫芦画瓢写一个你自己的，后期可以维护的控件。希望本文能帮助到你
代码在Github

截屏.gif

使用方法

拷贝文件到你的工程 JVshowKeyboardManger JVTextField
使用JVTextField 代替 UITextField
指定要移动的moveView self.textField.moveView=self.view;
跳转到下个页面之前要关闭键盘 重点

- (IBAction)pushNextViewController:(UIButton *)sender {
//     跳转到下一页之前 要关闭键盘，不然出现 keyboardToolBar不能隐藏的问题
    [self.view endEditing:YES];
    UIViewController *vc=[[UIViewController alloc]init];
    vc.view.backgroundColor=[UIColor greenColor];
    [self.navigationController pushViewController:vc animated:YES];
}

关键代码

主要由两个类组成

JVTextField : UITextField
JVshowKeyboardManger : NSObject

JVTextField.h

@interface JVTextField : UITextField
/**提供需要移动View层，本质上是可以移动main Window ,但为了个性化的需求，提供配置
*/
@property(nonatomic,weak)UIView* moveView;
@end

JVTextField.m

提供初始化方法

-(instancetype)initWithFrame:(CGRect)frame{
    self=[super initWithFrame:frame];
    [self Initialize];
    return self;
}
-(instancetype)init{
    self=[super init];
    [self Initialize];
    return self;
}

-(void)awakeFromNib{
    [super awakeFromNib];
    [self Initialize];
}

初始化添加通知

#pragma -mark 初始化
-(void)Initialize{
    [self addTarget:self action:@selector(addKeyboardNotification) forControlEvents:UIControlEventEditingDidBegin];
    [self addTarget:self action:@selector(removeKeyboardNotification) forControlEvents:UIControlEventEditingDidEnd];
}

#pragma -mark添加通知   由单独的一个类来完成
-(void)addKeyboardNotification{
  [JVshowKeyboardManger addNotificationWithTextFiled:self];
}

#pragma -mark 移除通知
-(void)removeKeyboardNotification{
    [JVshowKeyboardManger removeNotificationWithTextFiled:self];
}

JVshowKeyboardManger.h 提供接口

@interface JVshowKeyboardManger : NSObject

+(instancetype)shareClass;

/**添加通知*/
+(void)addNotificationWithTextFiled:(JVTextField*)textFiled;

/**移除通知*/
+(void)removeNotificationWithTextFiled:(JVTextField*)textFiled;

@end

JVshowKeyboardManger.m 提供实现

内部属性和宏定义

#define JVScreen_Width [UIScreen mainScreen].bounds.size.width

#define JVScreen_Height [UIScreen mainScreen].bounds.size.height

#define JVColor(R, G, B, A) [UIColor colorWithRed:R/255.0 green:G/255.0 blue:B/255.0 alpha:A]

static JVshowKeyboardManger *_sharedClass;

@interface JVshowKeyboardManger()
//为键盘添加一个完成按钮来关闭键盘
@property(strong,nonatomic)UIView* keyboardToolbar;
//moveView 在window中的 rect.origin.y
@property(assign,nonatomic) CGFloat viewY;
// 传递对象  for 遮挡键盘 处理
@property(nonatomic,weak)JVTextField* textFiled;

@end

keyboardToolbar懒加载

-(UIView *)keyboardToolbar{
    if (!_keyboardToolbar) {
        _keyboardToolbar=[[UIView alloc]initWithFrame:CGRectMake(0, JVScreen_Height, JVScreen_Width, 40)];
        _keyboardToolbar.backgroundColor=JVColor(208, 213, 218, 1.0);
        UIButton* complateBtn=[[UIButton alloc]initWithFrame:CGRectMake(JVScreen_Width-35-10, 0, 35, 40)];
        [complateBtn setTitle:@"完成" forState:0];
        [complateBtn setTitleColor:[UIColor blueColor] forState:0];
        complateBtn.titleLabel.font=[UIFont systemFontOfSize:14.f];
        [complateBtn addTarget:self action:@selector(closeTheKeyboard)forControlEvents:UIControlEventTouchUpInside];
        [_keyboardToolbar addSubview:complateBtn];
        NSEnumerator *frontToBackWindows = [UIApplication.sharedApplication.windows reverseObjectEnumerator];
        for (UIWindow *window in frontToBackWindows){
            BOOL windowOnMainScreen = window.screen == UIScreen.mainScreen;
            BOOL windowIsVisible = !window.hidden && window.alpha > 0;
            BOOL windowLevelNormal = window.windowLevel == UIWindowLevelNormal;
            if (windowOnMainScreen && windowIsVisible && windowLevelNormal) {
                [window addSubview:_keyboardToolbar];
                break;
            }
        }
        _keyboardToolbar.alpha=0;
    }
    return _keyboardToolbar;
}

创建单例

+(instancetype)shareClass{
    static dispatch_once_t token;
    dispatch_once(&token,^{
        _sharedClass = [[JVshowKeyboardManger alloc] init];
    });
    return _sharedClass;
}

添加通知

//添加通知
+(void)addNotificationWithTextFiled:(JVTextField*)textFiled{
   JVshowKeyboardManger* thisObject=[JVshowKeyboardManger shareClass];
   thisObject.textFiled=textFiled;
   //计算 moveView 在window中的 rect.origin.y
   thisObject.viewY=[thisObject relativeFrameForScreenWithView:thisObject.textFiled].origin.y;
   [thisObject addKeyboardNotification];
}


//移除通知
+(void)removeNotificationWithTextFiled:(JVTextField*)textFiled{
   JVshowKeyboardManger* thisObject=[JVshowKeyboardManger shareClass];
   [thisObject removeNotification];
}

辅助方法

#pragma -mark 计算moveview 在 window中的 rect
-(CGRect)relativeFrameForScreenWithView:(UIView *)v
{
    UIView *view = v;
    CGFloat x = .0;
    CGFloat y = .0;
    // root  uiwindow  superView ==nil
    while ([view superview])
    {
        x += view.frame.origin.x;
        y += view.frame.origin.y;
        view = view.superview;
        if ([view isKindOfClass:[UIScrollView class]]) {
            x -= ((UIScrollView *) view).contentOffset.x;
            y -= ((UIScrollView *) view).contentOffset.y;
        }
    }
    return CGRectMake(x, y, v.frame.size.width, v.frame.size.height);
}

#pragma -mark添加通知
-(void)addKeyboardNotification{
    
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillShow:)
                                                 name:UIKeyboardWillShowNotification
                                               object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillHide:)
                                                 name:UIKeyboardWillHideNotification
                                               object:nil];
}

#pragma -mark 移除通知
-(void)removeNotification{
    
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

处理键盘显示和隐藏

#pragma -mark 键盘显示时
- (void)keyboardWillShow:(NSNotification *)notif {
    if (self.textFiled==nil||self.textFiled.moveView==nil) return;
    CGSize kbSize = [[notif.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;//得到鍵盤的高度
    CGFloat kbHeight = kbSize.height;
    CGFloat viewY=self.viewY;
    CGFloat viewMaxY=viewY+self.textFiled.frame.size.height;
    CGFloat moveY=viewMaxY+kbHeight-[UIScreen mainScreen].bounds.size.height+40;
    if (moveY>0) {
            self.textFiled.moveView.bounds=CGRectMake(0, moveY, self.textFiled.moveView.frame.size.width, self.textFiled.moveView.frame.size.height);
    }
    self.keyboardToolbar.alpha=1;
    self.keyboardToolbar.frame=CGRectMake(self.keyboardToolbar.frame.origin.x, JVScreen_Height-kbHeight-40, self.keyboardToolbar.frame.size.width, self.keyboardToolbar.frame.size.height);
}
#pragma -mark 键盘隐藏
- (void)keyboardWillHide:(NSNotification *)notif {
    
    self.keyboardToolbar.alpha=0;
    
    [UIView animateWithDuration:0.25 animations:^{
         self.textFiled.moveView.bounds=CGRectMake(0, 0, self.textFiled.moveView.frame.size.width, self.textFiled.moveView.frame.size.height);
        self.keyboardToolbar.frame=CGRectMake(self.keyboardToolbar.frame.origin.x, JVScreen_Height, self.keyboardToolbar.frame.size.width, self.keyboardToolbar.frame.size.height);
    }completion:^(BOOL finished) {
        
    }];
}

点击关闭事件

#pragma -mark 点击关闭键盘
-(void)closeTheKeyboard{
    [[[UIApplication sharedApplication] keyWindow] endEditing:YES];
}

结束语

是不是很简单呢，你也可以实现一个textView的版本，限于篇幅，本文不在续写