您真的了解UITextField吗
你真的了解UITextField吗？
一：首先查看一下关于UITextField的定义
NS_CLASS_AVAILABLE_IOS(2_0) @interface UITextField : UIControl <UITextInput, NSCoding> @property(nullable, nonatomic,copy) NSString *text; //值 @property(nullable, nonatomic,copy) NSAttributedString *attributedText NS_AVAILABLE_IOS(6_0); //富文本的值 @property(nullable, nonatomic,strong) UIColor *textColor; // 文字色 @property(nullable, nonatomic,strong) UIFont *font; // 字体 @property(nonatomic) NSTextAlignment textAlignment; // 默认值 NSLeftTextAlignment 排版 @property(nonatomic) UITextBorderStyle borderStyle; // 默认值 UITextBorderStyleNone 边框的样式 @property(nonatomic,copy) NSDictionary<NSString *, id> *defaultTextAttributes NS_AVAILABLE_IOS(7_0); // 文本属性 用字典填充 @property(nullable, nonatomic,copy) NSString *placeholder; // 空值时的提示文字 @property(nullable, nonatomic,copy) NSAttributedString *attributedPlaceholder NS_AVAILABLE_IOS(6_0); // 富文本的空值提示文字 @property(nonatomic) BOOL clearsOnBeginEditing; // 默认值 NO 如果设为YES 再次编辑就清空 @property(nonatomic) BOOL adjustsFontSizeToFitWidth; // 默认值NO，若设为YES 当文字超出文本框宽度时，自动调整文字大小 @property(nonatomic) CGFloat minimumFontSize; // 默认值 0.0.最小可缩小的字号和adjustsFontSizeToFitWidth一起使用 @property(nullable, nonatomic,weak) id<UITextFieldDelegate> delegate; //代理 @property(nullable, nonatomic,strong) UIImage *background; //设置背景 注意只有UITextBorderStyleNone的时候改属性有效 @property(nullable, nonatomic,strong) UIImage *disabledBackground; //禁用的背景 @property(nonatomic,readonly,getter=isEditing) BOOL editing; //是否被编辑 @property(nonatomic) BOOL allowsEditingTextAttributes NS_AVAILABLE_IOS(6_0); // 默认值 NO @property(nullable, nonatomic,copy) NSDictionary<NSString *, id> *typingAttributes NS_AVAILABLE_IOS(6_0); @property(nonatomic) UITextFieldViewMode clearButtonMode; // 输入框中是否有个叉号 设置清除 何时显示 @property(nullable, nonatomic,strong) UIView *leftView; // 左边视图 @property(nonatomic) UITextFieldViewMode leftViewMode; // 在什么状态下显示 默认值 UITextFieldViewModeNever @property(nullable, nonatomic,strong) UIView *rightView; // 右边视图 @property(nonatomic) UITextFieldViewMode rightViewMode; // 默认值 UITextFieldViewModeNever //界面重写绘制行为 ////重写来重置边缘区域 - (CGRect)borderRectForBounds:(CGRect)bounds; //重写来重置文字区域 - (CGRect)textRectForBounds:(CGRect)bounds; //重写来重置占位符区域 - (CGRect)placeholderRectForBounds:(CGRect)bounds; //重写来重置编辑区域 - (CGRect)editingRectForBounds:(CGRect)bounds; //重写来重置clearButton位置,改变size可能导致button的图片失真 - (CGRect)clearButtonRectForBounds:(CGRect)bounds; - (CGRect)leftViewRectForBounds:(CGRect)bounds; - (CGRect)rightViewRectForBounds:(CGRect)bounds; //改变绘文字属性.重写时调用super可以按默认图形属性绘制,若自己完全重写绘制函数，就不用调用super了. - (void)drawTextInRect:(CGRect)rect; //重写改变绘制占位符属性.重写时调用super可以按默认图形属性绘制,若自己完全重写绘制函数，就不用调用super了. - (void)drawPlaceholderInRect:(CGRect)rect; @property (nullable, readwrite, strong) UIView *inputView; //代替标准的系统键盘 @property (nullable, readwrite, strong) UIView *inputAccessoryView; //编辑时显示在系统键盘或用户自定义的inputView上面的视图 @property(nonatomic) BOOL clearsOnInsertion NS_AVAILABLE_IOS(6_0); // 默认值NO @end
UITextField是继承于UIControl，并且遵循NSCoding及UITextInput的协议；UITextInput的协议作用是用来辅助键盘输入得协议，在需要用到键盘输入得地方都需要实现这个协议；
知识点1：UITextBorderStyle的枚举内容
typedef NS_ENUM(NSInteger, UITextBorderStyle) { UITextBorderStyleNone,/无任何边框 UITextBorderStyleLine,//黑色线框 UITextBorderStyleBezel,//边线+阴影 UITextBorderStyleRoundedRect //浅色带圆弧线框 };
知识点2：UITextFieldViewMode的枚举内容
typedef NS_ENUM(NSInteger, UITextFieldViewMode) { UITextFieldViewModeNever,//无清除按钮 UITextFieldViewModeWhileEditing,//编辑时出现清除按钮 UITextFieldViewModeUnlessEditing,//编辑时不出现，编辑后才出现清除按钮 UITextFieldViewModeAlways //一直显示清除按钮 };
知识点3：关于NSTextAlignment的说明，UITextAlignmentLeft （水平右对齐），UITextAlignmentCenter（水平居中对齐），UITextAlignmentRight （水平右对齐）；
知识点4：修改UITextField中关于Placeholder的着色
[self.myTextField setValue:[UIColor grayColor] forKeyPath:@"_placeholderLabel.textColor"]; 当然也可以采用另外一种方式： NSMutableAttributedString *attrString = [[NSMutableAttributedString alloc]initWithString:@"水印提示文字"]; [attrString addAttribute:NSForegroundColorAttributeNam value:[UIColor redColor] range:NSMakeRange(0, 2)]; myTextFieldattributedPlaceholder = attrString;
知识点5：关于leftView跟leftViewMode的运用
_relayTextField = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 0, 0)]; _relayTextField.backgroundColor = [UIColor whiteColor]; _relayTextField.font = [UIFont fontWithName:@"OpenSans" size:15.0]; _relayTextField.delegate = self; _relayTextField.layer.cornerRadius = 5.0f; _relayTextField.layer.masksToBounds = YES; _relayTextField.clearButtonMode = UITextFieldViewModeWhileEditing; _relayTextField.autocorrectionType = UITextAutocorrectionTypeNo; _relayTextField.autocapitalizationType = UITextAutocapitalizationTypeNone; _relayTextField.returnKeyType=UIReturnKeySend; UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(0, 10, 70, 37)]; label.font = [UIFont boldSystemFontOfSize:15]; label.adjustsFontSizeToFitWidth = YES; label.textColor = COLOR_WORD_GRAY_2; _relayTextField.leftView = label; _relayTextField.leftViewMode = UITextFieldViewModeAlways; [self addSubview:_relayTextField]; 设置显示的值： -(void)configuerWithName:(NSString*)name messageId:(NSString*)message_id { _name = name; _messageId = message_id; if ([_relayTextField.leftView isKindOfClass:[UILabel class]]) { ((UILabel*)_relayTextField.leftView).text = [NSString stringWithFormat:@"回复%@ :",name]; ((UILabel*)_relayTextField.leftView).textColor = COLOR_WORD_GRAY_2; } }
知识点6：inputView跟inputAccessoryView 默认是系统的键盘，比如有自定义的键盘就可以把它赋值给inputView;当然也可以是其它效果的视图，比如弹出选择器等；实例如下：
//自定义键盘，将原有的键盘隐藏，显示当前自定义视图 UIView *keyBoardContent = [[UIView alloc]initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, 100)]; keyBoardContent.backgroundColor = [UIColor darkGrayColor]; myTextField.inputView = keyBoardContent; UIView *subView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, 80)]; subView.backgroundColor = [UIColor greenColor]; myTextField.inputAccessoryView = subView;
二：UITextInputTraits的相关内容，UITextField遵循这个协议，用来辅助键盘输入得协议，在需要用到键盘输入得地方都需要实现这个协议
@protocol UITextInputTraits <NSObject> @optional @property(nonatomic) UITextAutocapitalizationType autocapitalizationType; // default is UITextAutocapitalizationTypeSentences @property(nonatomic) UITextAutocorrectionType autocorrectionType; //是否纠错 默认值 UITextAutocorrectionTypeDefault @property(nonatomic) UITextSpellCheckingType spellCheckingType NS_AVAILABLE_IOS(5_0); // default is UITextSpellCheckingTypeDefault; @property(nonatomic) UIKeyboardType keyboardType; // 键盘类型 默认值UIKeyboardTypeDefault @property(nonatomic) UIKeyboardAppearance keyboardAppearance; // 设定键盘显示风格 默认值 UIKeyboardAppearanceDefault @property(nonatomic) UIReturnKeyType returnKeyType; // default is UIReturnKeyDefault (See note under UIReturnKeyType enum) @property(nonatomic) BOOL enablesReturnKeyAutomatically; // 设定当文本框没有输入内容时键盘得返回键是否可用@property(nonatomic,getter=isSecureTextEntry) BOOL secureTextEntry; // 设定输入文本是否要受到隐藏保护，默认为NO不保护，设定为YES，则文本输入后为密码风格得保护 @end
知识点7：secureTextEntry是设置是否显示成密码的形式，此属性并不在UITextField里面
知识点8：UIReturnKeyType（UITextInputTraits中）的枚举内容如下
UIReturnKeyDefault ;//默认灰色按钮，标有Return UIReturnKeyGo ;//标有Go的蓝色按钮 UIReturnKeyGoogle ;//标有Google的蓝色按钮，用语搜索 UIReturnKeyJoin ;//标有Join的蓝色按钮 UIReturnKeyNext ;//标有Next的蓝色按钮 UIReturnKeyRoute ;//标有Route的蓝色按钮 UIReturnKeySearch ;//标有Search的蓝色按钮 UIReturnKeySend ;//标有Send的蓝色按钮 UIReturnKeyYahoo ;//标有Yahoo的蓝色按钮 UIReturnKeyYahoo ;//标有Yahoo的蓝色按钮 UIReturnKeyEmergencyCall;//紧急呼叫按钮
知识点9：autocapitalizationType（UITextInputTraits中）首字母是否大写
UITextAutocapitalizationTypeNone ;//不自动大写 UITextAutocapitalizationTypeWords ;//单词首字母大写 UITextAutocapitalizationTypeSentences ;//句子的首字母大写 UITextAutocapitalizationTypeAllCharacters;//所有字母都大写
知识点10：keyboardAppearance（UITextInputTraits中）键盘外观
UIKeyboardAppearanceDefault ;//默认外观，浅灰色 UIKeyboardAppearanceAlert ;//深灰石墨色
知识点11：autocorrectionType（UITextInputTraits中）是否纠错
UITextAutocorrectionTypeDefault ; //默认 UITextAutocorrectionTypeNo ; //不自动纠错 UITextAutocorrectionTypeYes ; //自动纠错
知识点12：使文本框在界面打开时就获取焦点，并弹出输入键盘：[myTextField becomeFirstResponder]; 使文本框失去焦点，并收回键盘[myTextFieldresignfirstresponder]
键盘收起其它方式 //方式 1: [[[UIApplication sharedApplication]keyWindow] endEditing:YES]; //方式 2: [[UIApplication sharedApplication]sendAction:@selector(resignFirstResponder) to:nil from:nil forEvent:nil]; //方式 3: [self.view endEditing:YES];
知识点13：因为UITextFiled是继承于UIControl,所以它也是有增加事件addTaget的效果
[myTextField addTarget:self action:@selector(textFieldDidChange:)//私有方法 forControlEvents:UIControlEventEditingChanged]; - (void)textFieldDidChange:(UITextField*)textField{//类似UIButton addTag..监听方法 NSLog(@"输入框内容 = %@",textField.text); }
知识点14：关于UITextFiled的NotificaitonCenter监听
UITextFieldTextDidBeginEditingNotification ;//监听开始编辑 UITextFieldTextDidChangeNotification ;//监听正在编辑 UITextFieldTextDidEndEditingNotification ;//监听结束编辑
实例： NSNotificationCenter *center = [NSNotificationCenter defaultCenter]; [center addObserver:self selector:@selector(texfFieldNotification:) name:UITextFieldTextDidChangeNotification object:nil]; - (void)texfFieldNotification:(NSNotification*)noti{//私有方法 NSLog(@"输入款变化了"); } 当然记得在用后时移除通知；
知识点15：监听键盘出现,知晓键盘CGRect
- (void)efObserverKeyBoardShowAndHidde{ //注册键盘出现 [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyBoardWasShow:) name:UIKeyboardWillShowNotification object:nil]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyBoardWillBeHidden:) name:UIKeyboardWillHideNotification object:nil]; } - (void)keyBoardWasShow:(NSNotification*)aNotification{ NSLog(@"键盘出现"); //键盘高度 //CGRect keyBoardFrame = [[[aNotification userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue]; } -(void)keyBoardWillBeHidden:(NSNotification*)aNotification{ NSLog(@"键盘消失"); } - (void)removeObserver{//移除所有通知 [[NSNotificationCenter defaultCenter]removeObserver:self]; }
三：UITextField定义的协议UITextFieldDelegate内容
@protocol UITextFieldDelegate <NSObject> @optional - (BOOL)textFieldShouldBeginEditing:(UITextField *)textField; // 返回一个BOOL值，指定是否循序文本字段开始编辑 - (void)textFieldDidBeginEditing:(UITextField *)textField; // 开始编辑时触发，获得焦点时 - (BOOL)textFieldShouldEndEditing:(UITextField *)textField; // 返回BOOL值，指定是否允许文本字段结束编辑，当编辑结束后 - (void)textFieldDidEndEditing:(UITextField *)textField; // 结束编辑 - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string; // 用户不段的输入，可以控制达到某些条件，禁止输入 - (BOOL)textFieldShouldClear:(UITextField *)textField; // 返回一个BOOL值指明是否满足什么条件清除内容 - (BOOL)textFieldShouldReturn:(UITextField *)textField; // 返回一个BOOL值，指明是否允许在按下回车键时结束编辑 @end
知识点1：运用实例
//限定输入条件 - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{ //得到输入框的内容 NSString * textString = [textField.text stringByReplacingCharactersInRange:range withString:string]; if ([string isEqualToString:@"\n"]) { NSLog(@"回车"); } if ([string isEqualToString:@""]) { NSLog(@"后退"); } if ([string isEqualToString:@" "]) { NSLog(@"空格"); //return NO;//禁止空格输入 } if (textString.length>4) { NSLog(@"输入超过5位数"); } //打印当前键盘输入模式,en-US,zh-Hans.... NSString *lang = [[UITextInputMode currentInputMode]primaryLanguage]; //ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789 //限制输入已知的字符 NSCharacterSet *cs = [[NSCharacterSet characterSetWithCharactersInString:@"0123456789\n"]invertedSet]; //按cs分离出数组,数组按@""分离出字符串 NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs]componentsJoinedByString:@""]; BOOL canChange = [string isEqualToString:filtered]; return YES; } - (BOOL)textFieldShouldReturn:(UITextField *)textField{//辞去职务 //主要是[receiver resignFirstResponder]在哪调用就能把receiver对应的键盘往下收 [textField resignFirstResponder]; return YES; }