鍵盤事件

• UIKeyboardWillShowNotification
• UIKeyboardDidShowNotification
  
• UIKeyboardWillHideNotification
  
• UIKeyboardDidHideNotification

使用場景：

• 計(jì)算鍵盤的高度，調(diào)整UI布局
• 根據(jù)鍵盤顯示隱藏執(zhí)行UI的動(dòng)畫

使用方法

  //注冊事件
 [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
 
 
 //接收事件
 -(void)keyboardWillShow:(NSNotification*)notification{ 
   NSDictionary*info=[notification userInfo]; 
   CGSize kbSize=[[info objectForKey:UIKeyboardFrameEndUserInfoKey]CGRectValue].size; 
   NSLog(@"keyboard changed, keyboard width = %f, height = %f",  
          kbSize.width,kbSize.height); 
  
  
} 


// NSNotification需要remove
-(void)viewDidUnload{ 
   [superviewDidUnload]; 
   [[NSNotificationCenter defaultCenter]removeObserver:self]; 
} 
 

繼承關(guān)系.png

屬性（Attributes）

UITextField的text屬性與userInteractionEnabled共用锋边。

   textField.text = @"密碼輸入框"          
// 輸入框默認(rèn)輸入文本捎稚，有時(shí)需求UITextField只可顯示不可編輯的,
// 此時(shí)起展示作用：用此屬性設(shè)置需要顯示的文本
// 然后設(shè)置UITextField不可交互textField.userInteractionEnabled = NO;
  textField.userInteractionEnabled = NO;

placeholder設(shè)置字體顏色祷安，大小

方法一：
textField.placeholder = @"密碼輸入框";  // 提示文本
[textField setValue：[UIColor colorWithRed:79/255.0f green:79/255.0f blue:79/255.0f alpha:0.5f] forKeyPath:@"_placeholderLabel.textColor"];
[textField setValue:[UIFont boldSystemFontOfSize:20] forKeyPath:@"_placeholderLabel.font"];

方法二：
textField.attributedPlaceholder = [[NSAttributedString alloc] initWithString:@"密碼輸入框"          
attributes:@{NSForegroundColorAttributeName: [UIColor colorWithRed:79/255.0f green:79/255.0f blue:79/255.0f alpha:0.5f],
NSFontAttributeName : [UIFont systemFontOfSize:20 weight:6],}];

邊框

 textField.borderStyle = UITextBorderStyleLine;
//效果如下圖所示
typedef NS_ENUM(NSInteger, UITextBorderStyle) {
    UITextBorderStyleNone,
    UITextBorderStyleLine,
    UITextBorderStyleBezel,
    UITextBorderStyleRoundedRect
};

Paste_Image.png

font屬性

 textField.font = [UIFont systemFontOfSize:14.0f];
 textField.textColor = [UIColor redColor];

 根據(jù)輸入文字動(dòng)態(tài)調(diào)整字體大小,需要設(shè)置一個(gè)最小字體大小
 textField.adjustsFontSizeToFitWidth = YES;
 textField.minimumFontSize = 10.0;//設(shè)置最小字體

設(shè)置輸入內(nèi)容的對其方式

textField.textAlignment = NSTextAlignmentLeft;

        NSTextAlignmentLeft      = 0,    // Visually left aligned
#if TARGET_OS_IPHONE
        NSTextAlignmentCenter    = 1,    // Visually centered
        NSTextAlignmentRight     = 2,    // Visually right aligned
#else /* !TARGET_OS_IPHONE */
        NSTextAlignmentRight     = 1,    // Visually right aligned
        NSTextAlignmentCenter    = 2,    // Visually centered
#endif
        NSTextAlignmentJustified = 3,    // Fully-justified. The last line in a paragraph is natural-aligned.
        NSTextAlignmentNatural   = 4,    // Indicates the default alignment for script



[textField setContentVerticalAlignment:UIControlContentVerticalAlignmentCenter];
[textField setContentHorizontalAlignment:UIControlContentHorizontalAlignmentRight];


UIControlContentVerticalAlignmentCenter  = 0,
    UIControlContentVerticalAlignmentTop     = 1,
    UIControlContentVerticalAlignmentBottom  = 2,
    UIControlContentVerticalAlignmentFill    = 3,



UIControlContentHorizontalAlignmentCenter = 0,
    UIControlContentHorizontalAlignmentLeft   = 1,
    UIControlContentHorizontalAlignmentRight  = 2,
    UIControlContentHorizontalAlignmentFill   = 3,

與鍵盤相關(guān)的屬性

    textField.keyboardType = UIKeyboardTypeNumberPad;   //設(shè)置鍵盤的樣式
//    typedef enum {
//        UIKeyboardTypeDefault,       默認(rèn)鍵盤蚯姆，支持所有字符
//        UIKeyboardTypeASCIICapable,  支持ASCII的默認(rèn)鍵盤
//        UIKeyboardTypeNumbersAndPunctuation,  標(biāo)準(zhǔn)電話鍵盤洋机，支持＋＊＃字符
//        UIKeyboardTypeURL,            URL鍵盤忠荞，支持.com按鈕 只支持URL字符
//        UIKeyboardTypeNumberPad,              數(shù)字鍵盤
//        UIKeyboardTypePhonePad,    電話鍵盤
//        UIKeyboardTypeNamePhonePad,   電話鍵盤多搀，也支持輸入人名
//        UIKeyboardTypeEmailAddress,   用于輸入電子 郵件地址的鍵盤
//        UIKeyboardTypeDecimalPad,     數(shù)字鍵盤 有數(shù)字和小數(shù)點(diǎn)
//        UIKeyboardTypeTwitter,        優(yōu)化的鍵盤，方便輸入@侧甫、#字符
//        UIKeyboardTypeAlphabet = UIKeyboardTypeASCIICapable,
//    } UIKeyboardType;


   textField.autocapitalizationType = UITextAutocapitalizationTypeNone;  //首字母是否自動(dòng)大寫
//    typedef enum {
//        UITextAutocapitalizationTypeNone, 不自動(dòng)大寫
//        UITextAutocapitalizationTypeWords,  單詞首字母大寫
//        UITextAutocapitalizationTypeSentences,  句子的首字母大寫
//        UITextAutocapitalizationTypeAllCharacters, 所有字母都大寫
//    } UITextAutocapitalizationType;
//
    
    
    textField.keyboardAppearance=UIKeyboardAppearanceDefault; //鍵盤外觀
//    typedef enum {
//        UIKeyboardAppearanceDefault珊佣， 默認(rèn)外觀，淺灰色
//        UIKeyboardAppearanceAlert披粟，     深灰 石墨色
//    } UIReturnKeyType;
    
    
    textField.returnKeyType =UIReturnKeyDone;   //return鍵變成什么鍵
//    typedef enum {
//        UIReturnKeyDefault, 默認(rèn) 灰色按鈕咒锻，標(biāo)有Return
//        UIReturnKeyGo,      標(biāo)有Go的藍(lán)色按鈕
//        UIReturnKeyGoogle, 標(biāo)有Google的藍(lán)色按鈕，用語搜索
//        UIReturnKeyJoin, 標(biāo)有Join的藍(lán)色按鈕
//        UIReturnKeyNext, 標(biāo)有Next的藍(lán)色按鈕
//        UIReturnKeyRoute, 標(biāo)有Route的藍(lán)色按鈕
//        UIReturnKeySearch, 標(biāo)有Search的藍(lán)色按鈕
//        UIReturnKeySend, 標(biāo)有Send的藍(lán)色按鈕
//        UIReturnKeyYahoo, 標(biāo)有Yahoo的藍(lán)色按鈕
//        UIReturnKeyYahoo, 標(biāo)有Yahoo的藍(lán)色按鈕
//        UIReturnKeyEmergencyCall, 緊急呼叫按鈕
//    } UIReturnKeyType;

其他相關(guān)屬性

//    以下幾個(gè)屬性通常不用守屉，通常為自定義控件先設(shè)置一個(gè)UIView UIView上面再放UIImageview 和 UITextField惑艇，設(shè)置UIView的boder屬性以滿足要求。
  leftView
  Property
  leftViewMode
  Property
  rightView
  Property
  rightViewMode
  Property


清空輸入框拇泛，常見于密碼輸入錯(cuò)入重新輸入時(shí)會(huì)清空輸入框滨巴。
 textField.clearButtonMode = UITextFieldViewModeWhileEditing;// sets when the clear button shows up編輯的時(shí)候清空輸入框
 //clearsOnInsertion// whether inserting text replaces the previous contents.插入的時(shí)候清空輸入框

    
//    typedef NS_ENUM(NSInteger, UITextFieldViewMode) {
//        UITextFieldViewModeNever,從不出現(xiàn)
//        UITextFieldViewModeWhileEditing,編輯時(shí)出現(xiàn)
//        UITextFieldViewModeUnlessEditing,除了編輯外都出現(xiàn)
//        UITextFieldViewModeAlways 一直出現(xiàn)
//    };
    
    textField.autocorrectionType = UITextAutocorrectionTypeNo;  //是否自動(dòng)糾錯(cuò)
//    typedef enum {
//        UITextAutocorrectionTypeDefault, 默認(rèn)
//        UITextAutocorrectionTypeNo,   不自動(dòng)糾錯(cuò)
//        UITextAutocorrectionTypeYes,  自動(dòng)糾錯(cuò)
//    } UITextAutocorrectionType;
    
secureTextEntry  啟用/禁用 UITextField對象的安全輸入功能。如果設(shè)置成YES則類似于密碼框內(nèi)容將顯示為圓點(diǎn)俺叭。

autocorrectionType  啟用/禁用 UITextFieldUI想的拼寫建議功能恭取，根據(jù)用戶輸入錯(cuò)誤的單詞提供修改建議

autocapitalizationType  設(shè)置 UITextField的自動(dòng)大寫功能，
none：關(guān)閉大寫功能
words： 單詞
sentences： 句子
allcharacters：所有字母
四種類型

委托

委托在開發(fā)中使用也比較廣泛熄守，例如手機(jī)號碼輸入框蜈垮，可以通過委托的shouldChangeCharactersInRange方法控制用戶能且只能輸入11位數(shù)字（例子講解）耗跛。另外，開發(fā)中通常要求輸入框內(nèi)容輸入后才讓按鈕可以點(diǎn)擊窃款。

委托的相關(guān)方法介紹

    - (BOOL)textFieldShouldBeginEditing:(UITextField *)textField{
        
        //返回一個(gè)BOOL值课兄，指定是否循序文本字段開始編輯
        
        return YES;
    }
    - (void)textFieldDidBeginEditing:(UITextField *)textField{
        
        //開始編輯時(shí)觸發(fā)牍氛，文本字段將成為first responder
        
    }
    - (BOOL)textFieldShouldEndEditing:(UITextField *)textField{
        
        //返回BOOL值晨继，指定是否允許文本字段結(jié)束編輯，當(dāng)編輯結(jié)束搬俊，文本字段會(huì)讓出first responder
        //要想在用戶結(jié)束編輯時(shí)阻止文本字段消失紊扬，可以返回NO
        //這對一些文本字段必須始終保持活躍狀態(tài)的程序很有用，比如即時(shí)消息
        
        
        return NO;
    }
    - (BOOL)textField:(UITextField*)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
        
        //當(dāng)用戶使用自動(dòng)更正功能唉擂，把輸入的文字修改為推薦的文字時(shí)餐屎，就會(huì)調(diào)用這個(gè)方法。
        //這對于想要加入撤銷選項(xiàng)的應(yīng)用程序特別有用
        //可以跟蹤字段內(nèi)所做的最后一次修改玩祟，也可以對所有編輯做日志記錄,用作審計(jì)用途腹缩。
        //要防止文字被改變可以返回NO
        //這個(gè)方法的參數(shù)中有一個(gè)NSRange對象，指明了被改變文字的位置空扎，建議修改的文本也在其中
        
        return YES;
    }
    - (BOOL)textFieldShouldClear:(UITextField *)textField{
        
        //返回一個(gè)BOOL值指明是否允許根據(jù)用戶請求清除內(nèi)容
        //可以設(shè)置在特定條件下才允許清除內(nèi)容
        
        return YES;
    }  
    -(BOOL)textFieldShouldReturn:(UITextField *)textField{  
        
        //返回一個(gè)BOOL值藏鹊，指明是否允許在按下回車鍵時(shí)結(jié)束編輯  
        //如果允許要調(diào)用resignFirstResponder 方法，這回導(dǎo)致結(jié)束編輯转锈，而鍵盤會(huì)被收起[textField resignFirstResponder];
        //查一下resign這個(gè)單詞的意思就明白這個(gè)方法了 
        
        return YES;  
    }

需求一：如下圖

1.phoneNumber輸入框最多只能輸入11位數(shù)字盘寡。
2.輸入框有內(nèi)容后按鈕變成可點(diǎn)擊狀態(tài)否則為灰色。

灰色狀態(tài)

可點(diǎn)擊狀態(tài)

CNNYRegisterInputView類為自定義的輸入框
在.h文件里面定義好delegate協(xié)議如下

@protocol CNNYRegisterInputViewTextFieldDelegate <NSObject>
@optional
-(void)didTextFieldUnChange;
@optional
- (void)didTextFieldChange:(UITextField *)textField andText:(NSString *)text;
@end

@interface CNNYRegisterInputView : UIView<UITextFieldDelegate>

@property(weak, nonatomic) id<CNNYRegisterInputViewTextFieldDelegate> delegate;
@property (nonatomic,strong) UITextField *textfield;
@property (nonatomic,strong) UIImageView *leftView;

- (instancetype)InitInputViewWithImage:(NSString *)placeHolder andImage:(NSString *)imageUrl;

- (void)setMode:(CNRegisterInputMode)mode;

@end

在.m文件如下

//
//  CNNYRegisterInputView.m
//  cheniu_shop
//
//  Created by brandonyum on 15/11/17.
//  Copyright ? 2015年 souche. All rights reserved.
//

#import "CNNYRegisterInputView.h"
#import <Masonry.h>
#import <UIColor+CNNHexColor.h>
#import "CNNYConstant.h"

static CGFloat const kMarginLfet = 16.0;
static NSString *const kBorderColorStr = @"#D1D1D1";

@interface CNNYRegisterInputView()

//@property (nonatomic,strong) UIImageView *leftView;
@property (nonatomic,strong) UIView *splitLine;

@end

@implementation CNNYRegisterInputView

- (instancetype)InitInputViewWithImage:(NSString *)placeHolder andImage:(NSString *)imageUrl{
    if (self == [super init]) {
        [self addSubview:self.textfield];
        [self addSubview:self.leftView];
        [self addSubview:self.splitLine];
        [self Constraints];
        
        [self.textfield setPlaceholder:CNNShopLoc(placeHolder)];
        [self.textfield setContentVerticalAlignment:UIControlContentVerticalAlignmentCenter];
        [self.leftView setImage:[UIImage imageNamed:imageUrl]];
       
        [self.layer setBorderColor:[UIColor cnn_colorWithHexString:kBorderColorStr].CGColor];
        [self.layer setBorderWidth:0.5];
        self.layer.cornerRadius = 8;
        [self setBackgroundColor:[UIColor whiteColor]];
    }
    return self;

}
- (instancetype)init{
    self = [super init];
    if (self) {
        [self addSubview:self.textfield];
        [self addSubview:self.leftView];
        [self addSubview:self.splitLine];
        [self Constraints];
        
        [self.layer setBorderColor:[UIColor cnn_colorWithHexString:kBorderColorStr].CGColor];
        [self.layer setBorderWidth:0.5];
        [self setBackgroundColor:[UIColor whiteColor]];
    }
    return self;
}

- (void)Constraints{
    __weak typeof(self) weakSelf = self;
    [self.leftView mas_remakeConstraints:^(MASConstraintMaker *make) {
        make.left.equalTo(weakSelf.mas_left).offset(kMarginLfet);
        make.top.bottom.equalTo(weakSelf);
        make.width.equalTo(@(18.0));
    }];
    
    [self.splitLine mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.equalTo(weakSelf.leftView.mas_right).offset(8.0);
        make.top.equalTo(weakSelf).offset(12.0);
        make.bottom.equalTo(weakSelf).offset(-12.0);
        make.width.equalTo(@(0.3));
    }];
    
    [self.textfield mas_remakeConstraints:^(MASConstraintMaker *make) {
        make.left.equalTo(weakSelf.splitLine.mas_right).offset(8.0);
        make.top.bottom.equalTo(weakSelf);
        make.right.equalTo(weakSelf.mas_right).offset(-kMarginLfet);
    }];
}

- (UIView *)splitLine{
    if (!_splitLine) {
        _splitLine = [[UIView alloc]init];
        [_splitLine setBackgroundColor:[UIColor colorWithRed:181/255.0f green:181/255.0f blue:182/255.0f alpha:0.4]];
    }
    return _splitLine;
}

- (UITextField *)textfield{
    if (!_textfield) {
        _textfield = [[UITextField alloc]init];
        [_textfield setFont:[UIFont systemFontOfSize:16.0]];
        [_textfield setTextColor:[UIColor cnn_colorWithHexString:@"#808080"]];
        [_textfield setClearButtonMode:UITextFieldViewModeWhileEditing];
        [_textfield setContentHorizontalAlignment:UIControlContentHorizontalAlignmentCenter];
    }
    return _textfield;
}

- (UIImageView *)leftView{
    if (!_leftView) {
        _leftView = [[UIImageView alloc]init];
        [_leftView setContentMode:UIViewContentModeCenter];
    }
    return _leftView;
}
//實(shí)現(xiàn)UITextField的委托協(xié)議
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    
        NSMutableString *text = [NSMutableString stringWithString:textField.text];
        [text replaceCharactersInRange:range withString:string];
        if (text.length > 0) {
        //在輸入框不為空的時(shí)候用定義好的協(xié)議發(fā)送通知撮慨，更新UI
            if ([self.delegate respondsToSelector:@selector(didTextFieldChange:andText:)]) {
                [self.delegate didTextFieldChange:textField andText:text];
            }
            
        }else{
    //在輸入框delete為空的時(shí)候用定義好的協(xié)議發(fā)送通知竿痰，更新UI
            if ([self.delegate respondsToSelector:@selector(didTextFieldUnChange)]) {
                [self.delegate didTextFieldUnChange];
            }
        }
      
    //限制textField的長度不超過11位
            if (text.length > 11) {
                return NO;
            }else{
                return YES;
            }
       
    
    }

- (void)setMode:(CNRegisterInputMode)mode{
    if (mode == CNRegisterInputModePhone) {
        [_textfield setKeyboardType:UIKeyboardTypeNumberPad];
        [_textfield setSecureTextEntry:NO];
    }else{
        [_textfield setKeyboardType:UIKeyboardTypeDefault];
        [_textfield setSecureTextEntry:YES];
    }
}

@end

需求優(yōu)化，

上面代碼中shouldChangeCharactersInRange方法僅僅只是判斷了text.length的長度砌溺，大于指定長度假設(shè)為11位影涉，大于11后return NO。

• 思考1：用戶復(fù)制粘貼怎么辦规伐。像微博那種限制140字蟹倾，如果用戶復(fù)制了200字到輸入框中，這樣限制用戶輸入長度就無效了楷力。
• 思考2：用戶輸入了11位后喊式，發(fā)現(xiàn)前面輸錯(cuò)了，怎么辦∠舫現(xiàn)在已經(jīng)是return NO了岔留，發(fā)現(xiàn)根本無法更改。

解決示例代碼：

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    NSString *minValue = [self.field.valueRange valueForKey:min];
    NSString *maxValue = [self.field.valueRange valueForKey:max];
   //解決問題2检柬，刪除按鈕献联，確認(rèn)等按鈕其長度為0竖配，所以判斷當(dāng)輸入長度為0的時(shí)候讓按鈕有效返回YES。
    if (string.length == 0) {
        return YES;
    }
    
    if (textField.tag == 2) {
        if (string.length +range.location <= maxValue.length ) {
            return YES;
        }else{
            return NO;
        }
    }else{
        if (string.length + range.location > minValue.length) {
            return NO;
        }else{
            return YES;
        }
    }
}