iOS中的UITextField使用总结

1、基本设置

键盘类型

要显示中文，还得设置info.plist中

Localization native development region 为 cn

UITextField *textF = [[UITextField alloc]init];
//需要先把样式给取消掉
textF.borderStyle = UITextBorderStyleNone;
//然后再设置背景图片
textF.background = [UIImage imageNamed:@"chat_send_nor"];
 //设置背景 
 text.disabledBackground = [UIImage imageNamed:@"cc.png"];
//光标如果太靠近边框，可以进行如下设置
UIView *leftView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 10, 0)];
textF.leftView = leftView;
textF.leftViewMode = UITextFieldViewModeAlways;
//占位文字颜色
[textF setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];
textF.tintColor = [UIColor blackColor];

输入框中是否有个叉号，在什么时候显示，用于一次性删除输入框中的内容

 //输入框中是否有个叉号，在什么时候显示，用于一次性删除输入框中的内容
  text.clearButtonMode = UITextFieldViewModeAlways;
   typedef enum {
    UITextFieldViewModeNever,  重不出现
    UITextFieldViewModeWhileEditing, 编辑时出现
    UITextFieldViewModeUnlessEditing,  除了编辑外都出现
    UITextFieldViewModeAlways   一直出现
} UITextFieldViewMode;

是否纠错

 //是否纠错
  text.autocorrectionType = UITextAutocorrectionTypeNo;
typedef enum {
    UITextAutocorrectionTypeDefault, 默认
    UITextAutocorrectionTypeNo,   不自动纠错
    UITextAutocorrectionTypeYes,  自动纠错
} UITextAutocorrectionType;

再次编辑就清空

 //再次编辑就清空
  text.clearsOnBeginEditing = YES;

对齐方式

 //内容对齐方式
  text.textAlignment = UITextAlignmentLeft;
//内容的垂直对齐方式  UITextField继承自UIControl,此类中有一个属性contentVerticalAlignment
_countryTextF.contentVerticalAlignment = UIControlContentVerticalAlignmentTop;

内容填充

 //设置为YES时文本会自动缩小以适应文本窗口大小.默认是保持原来大小,而让长文本滚动  
  textFied.adjustsFontSizeToFitWidth = YES;
//设置自动缩小显示的最小字体大小
  text.minimumFontSize = 20;
  _countryTextF.font = [UIFont systemFontOfSize:25];

首字母是否大写

 //首字母是否大写
  text.autocapitalizationType = UITextAutocapitalizationTypeNone;
typedef enum {
    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
} UITextAutocapitalizationType;

最右侧加图片是以下代码 左侧类似

//最右侧加图片是以下代码   左侧类似

    UIImageView *image=[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"right.png"]];

    text.rightView=image;

    text.rightViewMode = UITextFieldViewModeAlways; 

typedef enum {

    UITextFieldViewModeNever,

    UITextFieldViewModeWhileEditing,

    UITextFieldViewModeUnlessEditing,

    UITextFieldViewModeAlways

} UITextFieldViewMode;

设置键盘背景颜色

    self.countryTextF.keyboardAppearance = UIKeyboardAppearanceDark;
    self.birthDayTextF.keyboardAppearance = UIKeyboardAppearanceLight;

shift按键

 textView.autocapitalizationType = UITextAutocapitalizationTypeNone;//shift不能自动有效
 textView.autocapitalizationType = UITextAutocapitalizationTypeWords;//单词开头的情况下自动有效，就是每输入一个单词在开头的时候自动大写，第二个字母开始就自动小写
 textView.autocapitalizationType = UITextAutocapitalizationTypeSentences;//文章开头有效
 textView.autocapitalizationType = UITextAutocapitalizationTypeAllCharacters;//一直有效（就是一直大写）

自动矫正功能

 _countryTextF.autocorrectionType =  UITextAutocorrectionTypeYes;

2、

//是否允许开始编辑
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField{
    return YES;
}

//开始编辑时调用(成为第一响应者)
// became first responder
- (void)textFieldDidBeginEditing:(UITextField *)textField{
    //NSLog(@"%s",__func__);
}

//是否允许结束编辑
- (BOOL)textFieldShouldEndEditing:(UITextField *)textField{
    return YES;
}

//当结束编辑时调用
- (void)textFieldDidEndEditing:(UITextField *)textField{
    NSLog(@"%s",__func__);
}

//是否允许改变文本框内容(拦截用户输入)
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    return NO;
}

监听return处理（没有内容则无法点击）

self.countryTextF.enablesReturnKeyAutomatically = YES；

    self.countryTextF.returnKeyType = UIReturnKeyNext;
    self.birthDayTextF.returnKeyType = UIReturnKeyGoogle;
    self.cityTextF.returnKeyType = UIReturnKeyContinue;
    - (BOOL)textFieldShouldReturn:(UITextField *)textField {
    NSLog(@"%s",__func__);
    return YES;
}


typedef enum { 
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 
} UIReturnKeyType;

3、监听文字改变

方式1

[textField addTarget:self action:@selector(textEditingChanged:) forControlEvents:UIControlEventEditingChanged];

- (void)textEditingChanged:(UITextField *)textField {
     NSLog(@"%@",textField.text);
}

方式2

[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(changeTextField:) name:UITextFieldTextDidChangeNotification object:textF];

- (void)changeTextField:(NSNotification *)notification {
     UITextField *textField = [notification object];
     NSLog(@"%@",textField.text);
}

代理监听

• 此代理只能输出==上次已有==的字符(本次点击键盘输入的文字不会被输出)，所以我认为此代理==适合做输入字符串内容的控制==

  只能输入数字

  ```
• (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
  NSCharacterSet *charSet = [[NSCharacterSet characterSetWithCharactersInString:@”0123456789”] invertedSet];
  NSString *filteredStr = [[string componentsSeparatedByCharactersInSet:charSet] componentsJoinedByString:@””];
  if ([string isEqualToString:filteredStr]) {

    return YES;

  }
  return NO;

  ##### 输入固定位数

• (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
  NSString *numberString = [textField.text stringByReplacingCharactersInRange:range withString:string];
  if (numberString.length > 5) {

    textField.text = [numberString substringToIndex:5];
    return NO;

  }
  return YES;
  }

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

    if (textField == self.liveThemeTextField) {
    //这里的if时候为了获取删除操作,如果没有此if会造成当达到字数限制后删除键也不能使用的后果.
        if (range.length == 1 && string.length == 0) {
            return YES;
        }
        //so easy
        else if (self.liveThemeTextField.text.length >= 30) {
            self.liveThemeTextField.text = [textField.text substringToIndex:30];
            return NO;
        }
    }
    return YES;
}

---

swift（2018年更新）

当用户输入达到最大限制字数的时候,此时的删除按钮不能使用

    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        if range.length == 1 && string.count == 0 {
            return true 
        }
        if (textField.text?.count ?? 0) > 10 {
            return false
        }
        return true
    }