iOS中UITextField控制元件和UITextView控制元件經常需要對鍵盤做彈起和退出動作,一般使用的是becomeFirstResponder和resignFirstResponder方法，但是這樣也有明顯的缺點，就是會在鍵盤的彈起退出過程中經常出現黑邊，或者斷層，導致效果很不好看，在網上找了些資料，自己做了一個自定義的輸入框來解決這個問題，效果類似於微信和QQ的聊天框。

KLCPopKeyBoard.h

#import <UIKit/UIKit.h>
@class KLCPopKeyBoard;
@protocol KLCPopKeyBoardDelegate <NSObject>

- (void)popKeyBoard:(KLCPopKeyBoard *)popKeyBoard didClickSend:(BOOL)didClickSend;
- (void)popKeyBoardHide;
- (void)popKeyBoardShow;

@end


@interface KLCPopKeyBoard : UIView

@property (nonatomic, weak) id<KLCPopKeyBoardDelegate> delegate;
@property (nonatomic, copy) NSString *content;//輸入框內容
@property (nonatomic, copy) NSString *placeholder;

- (instancetype)initWithPlaceholder:(NSString *)placeholder buttonTitle:(NSString *)buttonTitle;

//成對使用,可以保證一直在螢幕中出現
- (void)viewWillAppear;
- (void)viewWillDisAppear;

//成對使用,可以保證單次顯示
- (void)show;
- (void)hide;

//推出鍵盤和退出鍵盤
- (void)pushKeyboard;
- (void)hideKeyboard;

@end
 

KLCPopKeyBoard.m

#import "KLCPopKeyBoard.h"

#define KeyBoardHeight 44

#define FullScreen_Height [[UIScreen mainScreen] bounds].size.height
#define FullScreen_Width [[UIScreen mainScreen] bounds].size.width

static inline UIViewAnimationOptions NgAnimationOptionsWithCurve(UIViewAnimationCurve curve)
{
    switch (curve) {
        case UIViewAnimationCurveEaseInOut:
            return UIViewAnimationOptionCurveEaseInOut;
        case UIViewAnimationCurveEaseIn:
            return UIViewAnimationOptionCurveEaseIn;
        case UIViewAnimationCurveEaseOut:
            return UIViewAnimationOptionCurveEaseOut;
        case UIViewAnimationCurveLinear:
            return UIViewAnimationOptionCurveLinear;
    }
    return 0;
}

@interface KLCPopKeyBoard()<UITextFieldDelegate>
{
    UIView *_bgView;
    
    UITextField *_field;
    
    UIButton *_button;
    
    NSString *_placeholder;
    
    NSString *_buttonTitle;
    
    //BOOL _willHidden;
}
@end

@implementation KLCPopKeyBoard

- (instancetype)init
{
    self = [super init];
    if (self) {
        _placeholder = @"";
        _buttonTitle = @"傳送";
        [self setupUI];
    }
    return self;
}

- (instancetype)initWithPlaceholder:(NSString *)placeholder buttonTitle:(NSString *)buttonTitle
{
    self = [super init];
    if (self) {
        _placeholder = placeholder;
        _buttonTitle = buttonTitle;
        [self setupUI];
    }
    return self;
}

- (void)setupUI
{
    self.frame = CGRectMake(0, FullScreen_Height - KeyBoardHeight, FullScreen_Width, KeyBoardHeight);
    
    _bgView = [[UIView alloc]init];
    _bgView.frame = self.bounds;
    _bgView.backgroundColor = [UIColor whiteColor];
    [self addSubview:_bgView];
    
    UIView *line = [[UIView alloc]init];
    line.frame = CGRectMake(0, 0, FullScreen_Width, 0.5);
    line.backgroundColor = [UIColor blackColor];
    [_bgView addSubview:line];
    
    CGFloat height = 30;
    CGFloat topMargin = (KeyBoardHeight - height)/2;
    CGFloat leftMargin = 10;
    CGFloat buttonWidth = 44;
    CGFloat buttonHeight = 30;
    
    _field = [[UITextField alloc]init];
    _field.frame = CGRectMake(leftMargin, topMargin, FullScreen_Width - leftMargin*3 - buttonWidth, height);
    _field.backgroundColor = [UIColor whiteColor];
    _field.textColor = [UIColor blackColor];
    _field.font = [UIFont systemFontOfSize:14];
    _field.returnKeyType = UIReturnKeyDone;
    _field.layer.cornerRadius = 3;
    _field.clipsToBounds = YES;
    _field.delegate = self;
    _field.placeholder = _placeholder;
    [_bgView addSubview:_field];
    
    _button = [[UIButton alloc]init];
    _button.frame = CGRectMake(CGRectGetMaxX(_field.frame)+leftMargin, topMargin, buttonWidth, buttonHeight);
    [_button setTitle:_buttonTitle forState:UIControlStateNormal];
    _button.titleLabel.font = [UIFont systemFontOfSize:14];
    _button.backgroundColor = [UIColor yellowColor];
    [_button setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    _button.layer.cornerRadius = 3;
    _button.clipsToBounds = YES;
    [_button addTarget:self action:@selector(didClickButton:) forControlEvents:UIControlEventTouchUpInside];
    [_bgView addSubview:_button];
}


#pragma mark -傳送
- (void)didClickButton:(UIButton *)btn
{
    
    _content = _field.text;
    if ([_delegate respondsToSelector:@selector(popKeyBoard:didClickSend:)]) {
        [_delegate popKeyBoard:self didClickSend:YES];
        _field.text = nil;
        [self hideKeyboard];
    }
}

- (void)setPlaceholder:(NSString *)placeholder
{
    _placeholder = placeholder;
    _field.placeholder = placeholder;
}

#pragma mark - 展示控制
- (void)viewWillAppear
{
    [self show];
}

- (void)viewWillDisAppear
{
    [self hide];
}

- (void)show
{
    dispatch_async(dispatch_get_main_queue(), ^{
        for (UIView *view in [UIApplication sharedApplication].keyWindow.subviews) {
            if ([view isKindOfClass:[KLCPopKeyBoard class]]) {
                return;
            }
        }
        [[UIApplication sharedApplication].keyWindow addSubview:self];
        [[UIApplication sharedApplication].keyWindow bringSubviewToFront:self];
    });
}

-(void)hide
{
    dispatch_async(dispatch_get_main_queue(), ^{
        [self removeFromSuperview];
    });
    /*
    if ([_field isFirstResponder]) {
        _willHidden = YES;
        [self hideKeyboard];
    } else {
        dispatch_async(dispatch_get_main_queue(), ^{
            [self removeFromSuperview];
        });
    }*/
}

#pragma mark - 推出和退出鍵盤
- (void)pushKeyboard
{
    if (![_field isFirstResponder]) {
        [_field becomeFirstResponder];
        if ([_delegate respondsToSelector:@selector(popKeyBoardShow)]) {
//            [_delegate popKeyBoardShow];
        }
    }
}

- (void)hideKeyboard
{
    if ([_field isFirstResponder]) {
        [_field resignFirstResponder];
        if ([_delegate respondsToSelector:@selector(popKeyBoardHide)]) {
            [_delegate popKeyBoardHide];
        }
    }
}

#pragma mark - 鍵盤監聽
- (void)startListenKeyboard
{
    [[NSNotificationCenter defaultCenter]
     addObserver:self
     selector:@selector(onKeyboardWillShow:)
     name:UIKeyboardWillShowNotification object:nil];
    
    [[NSNotificationCenter defaultCenter]
     addObserver:self
     selector:@selector(onKeyboardWillHide:)
     name:UIKeyboardWillHideNotification object:nil];
    
    [[NSNotificationCenter defaultCenter]
     addObserver:self
     selector:@selector(onKeyboardDidShow:)
     name:UIKeyboardDidShowNotification object:nil];
    
    [[NSNotificationCenter defaultCenter]
     addObserver:self
     selector:@selector(onKeyboardDidHide:)
     name:UIKeyboardDidHideNotification object:nil];
    
    [[NSNotificationCenter defaultCenter]
     addObserver:self
     selector:@selector(onKeyboardWillChangeFrame:)
     name:UIKeyboardWillChangeFrameNotification object:nil];
    
    [[NSNotificationCenter defaultCenter]
     addObserver:self
     selector:@selector(onKeyboardDidChangeFrame:)
     name:UIKeyboardDidChangeFrameNotification object:nil];
}

- (void)endListenKeyboard
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

- (void)onKeyboardWillShow:(NSNotification *)note {
    
    
}
- (void)onKeyboardDidShow:(NSNotification *)note {
    


}
- (void)onKeyboardWillHide:(NSNotification *)note {
    if ([_delegate respondsToSelector:@selector(popKeyBoardHide)]) {
        [_delegate popKeyBoardHide];
    }
    
}
- (void)onKeyboardDidHide:(NSNotification *)note {
    
}

- (void)onKeyboardWillChangeFrame:(NSNotification *)note {
    //Log("%@",note.userInfo);
    [self captureKeyboardFrameWithInfo:note.userInfo];
}
- (void)onKeyboardDidChangeFrame:(NSNotification *)note {
    //Log("%@",note.userInfo);
    //[self captureKeyboardFrameWithInfo:note.userInfo];
}

- (void)captureKeyboardFrameWithInfo:(NSDictionary *)info
{
    CGRect _endFrame = [info[UIKeyboardFrameEndUserInfoKey] CGRectValue];
    NSTimeInterval _animationDuration = [info[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    UIViewAnimationCurve animationCurve = (UIViewAnimationCurve)[info[UIKeyboardAnimationCurveUserInfoKey] integerValue];
    
    [UIView animateWithDuration:_animationDuration delay:0 options:NgAnimationOptionsWithCurve(animationCurve) animations:^{
        CGRect myFrame = self.frame;
        myFrame.origin.y = _endFrame.origin.y - KeyBoardHeight;
        self.frame = myFrame;
    } completion:^(BOOL finished) {
        /*if (_willHidden) {
            dispatch_async(dispatch_get_main_queue(), ^{
                [self removeFromSuperview];
            });
            _willHidden = NO;
        }*/
    }];
}

#pragma mark - TextField delegate
-(BOOL)textFieldShouldBeginEditing:(UITextField *)textField
{
    if ([_delegate respondsToSelector:@selector(popKeyBoardHide)]) {
        [_delegate popKeyBoardShow];
    }
    
    [self startListenKeyboard];
    return YES;
}
-(BOOL)textFieldShouldEndEditing:(UITextField *)textField
{
    return YES;
}
-(void)textFieldDidEndEditing:(UITextField *)textField
{
    self.content = textField.text;
    [self endListenKeyboard];
}

-(BOOL)textFieldShouldReturn:(UITextField *)textField
{
    
//    [textField resignFirstResponder];
//    if ([_delegate respondsToSelector:@selector(popKeyBoard:didClickSend:)]) {
//        [_delegate popKeyBoard:self didClickSend:YES];
//        _field.text = nil;
//        if ([_delegate respondsToSelector:@selector(popKeyBoardHide)]) {
//            [_delegate popKeyBoardHide];
//        }
//    }
    
    [self didClickButton:nil];
    
    return YES;
}

@end