OC 基础 UITextField

一直觉得自己写的不是技术，而是情怀，一个个的教程是自己这一路走来的痕迹。靠专业技能的成功是最具可复制性的，希望我的这条路能让你们少走弯路，希望我能帮你们抹去知识的蒙尘，希望我能帮你们理清知识的脉络，希望未来技术之巅上有你们也有我。

1.属性

1.使用

UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(50, 100, 150, 30)];
[self.view addSubview:textField];
//设置默认文本
textField.text = @"请输入文本内容";
//设置文本颜色
textField.textColor = [UIColor redColor];
//设置对齐方式
textField.textAlignment = NSTextAlignmentCenter;
//设置文本样式和大小
textField.font = [UIFont fontWithName:@"wawati sc" size:20];
//设置textFild边框
textField.borderStyle = UITextBorderStyleRoundedRect;
//设置提示文本
textField.placeholder = @"请输入文本内容";
//设置textField不可编辑
textField.enabled = YES;
//显示本文清空按钮
textField.clearButtonMode = UITextFieldViewModeAlways;
//开始编辑是是否删除原有的内容
textField.clearsOnBeginEditing = YES;
//设置编辑框中的内容密码显示
textField.secureTextEntry = YES;
//设置键盘上的样式
textField.keyboardType = UIKeyboardTypeNamePhonePad;
//设置键盘上return键的类型
/**
 UIReturnKeyDefault,
 UIReturnKeyGo,
 UIReturnKeyGoogle,
 UIReturnKeyJoin,
 UIReturnKeyNext,
 UIReturnKeyRoute,
 UIReturnKeySearch,
 UIReturnKeySend,
 UIReturnKeyYahoo,
 UIReturnKeyDone,
 UIReturnKeyEmergencyCall,
 UIReturnKeyContinue,
 */
textField.returnKeyType = UIReturnKeySearch;

//添加左视图    还可以添加右视图(不举例子)
UIView *leftView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 25, 25)];
leftView.backgroundColor = [UIColor grayColor];
textField.leftView = leftView;

//代理
textField.delegate = self;


#pragma mark - 开始编辑
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField{
    return YES;
}

#pragma mark - 已经编辑
- (void)textFieldDidBeginEditing:(UITextField *)textField{
    
}

#pragma mark - 结束编辑
- (BOOL)textFieldShouldEndEditing:(UITextField *)textField{
    return YES;
}

#pragma mark - 已经结束编辑-1
- (void)textFieldDidEndEditing:(UITextField *)textField{
    
}

#pragma mark - 已经结束编辑-2
- (void)textFieldDidEndEditing:(UITextField *)textField reason:(UITextFieldDidEndEditingReason)reason API_AVAILABLE(ios(10.0)){
    
}

#pragma mark - 正在发生改变
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    return YES;
}

#pragma mark - 已经发生改变
- (void)textFieldDidChangeSelection:(UITextField *)textField API_AVAILABLE(ios(13.0), tvos(13.0)){
    
}

#pragma mark - 点击删除按键
- (BOOL)textFieldShouldClear:(UITextField *)textField{
    return YES;
}

#pragma mark - 点击返回按键
- (BOOL)textFieldShouldReturn:(UITextField *)textField{
    return YES;
}


//取消编辑
[[[UIApplication sharedApplication] keyWindow] endEditing:YES];

3.需求

3.1输入框设置左边输入边距

self.textField.leftView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 8, 0)];
self.textField.leftViewMode = UITextFieldViewModeAlways;

3.2点击空白处收回键盘

UITapGestureRecognizer *tap=[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tap)];
[self.view addGestureRecognizer:tap];
tap.numberOfTapsRequired=1;
tap.numberOfTouchesRequired=1;
    
- (void)tap{
    [self.view endEditing:YES];
}

3.2进来页面默认TextField选中把键盘弹起来

[self.OfflineAdressTextField becomeFirstResponder];

3.3键盘设置

self.textField.keyboardType = UIKeyboardTypeNumberPad;

UIKeyboardTypeNumberPad（纯数字）

UIKeyboardTypeDefault（默认）

UIKeyboardTypeASCIICapable(英文)

UIKeyboardTypeNumbersAndPunctuation（搜狗数字）

UIKeyboardTypeURL（URL英文）

UIKeyboardTypePhonePad （算数 数字）

UIKeyboardTypeEmailAddress (Emil 英文)

UIKeyboardTypeDecimalPad(价格 数字)

UIKeyboardTypeTwitter

UIKeyboardTypeWebSearch

UIKeyboardTypeASCIICapableNumberPad

UIKeyboardTypeAlphabet

3.4实时获取输入的值

OC

#pragma mark - 正在发生改变
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    if (textField == self.OfflineAdressTextField) {
        self.adress = [textField.text stringByReplacingCharactersInRange:range withString:string];
    }else if(textField == self.OfflineUrlTextField){
        self.url = [textField.text stringByReplacingCharactersInRange:range withString:string];
    }
}

Swift

extension ShowAddView: UITextFieldDelegate {
    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        let rag = textField.text?.toRange(range)
        self.title = textField.text?.replacingCharacters(in: rag!, with: string) ?? String()
        return true
    }
}

extension String {
    func toRange(_ range: NSRange) -> Range<String.Index>?{
        guard let from16 = utf16.index(utf16.startIndex, offsetBy: range.location, limitedBy: utf16.endIndex) else { return nil }
        guard let to16 = utf16.index(from16, offsetBy: range.length, limitedBy: utf16.endIndex) else { return nil }
        guard let from = String.Index(from16, within: self) else { return nil }
        guard let to = String.Index(to16, within: self) else { return nil }
        return from ..< to
    }
}

3.5 点击删除按键 监听把值清空

点击删除按键的时候，textfield已经把文本框的值已经清空了，我们只需要在监听的实现方法里面，把自定义保存文本的值也跟着清空就可以

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

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

3.6 监听当前输入框是否为空

注意：代理方法有一个缺点，它获取实时textField的值是监听键盘的删除按键，如果是textfield的清空文本按键清空输入框的文本是没有办法监听。要解决这个方法需要用方法二才能实时监听到值的变化

方法一：代理方法。

self.textField.delegate = self;

<UITextFieldDelegate>

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    NSString *value = [textField.text stringByReplacingCharactersInRange:range withString:string];
    NSLog(@"value: %@",value);
    return YES;
}

方法二：监听方法

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

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

3.7 禁止复制粘贴

之前我写过一遍文章
禁止复制粘贴

3.8 自定义删除文本按键

//自定义 textField 的清除按钮
UIButton *clearBtn = [self.textField valueForKey:@"_clearButton"];
[clearBtn setImage:[UIImage imageNamed:@"home_search_normal"] forState:UIControlStateNormal];

3.9限制输入个数

extension ShowAddView: UITextFieldDelegate {
    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        let rag = textField.text?.toRange(range)
        let text = textField.text?.replacingCharacters(in: rag!, with: string) ?? String()
        if text.count > 60 {
            return false
        } else {
            self.fileName = text//在范围内才赋值
            return true
        }
    }
}

extension String {
    func toRange(_ range: NSRange) -> Range<String.Index>?{
        guard let from16 = utf16.index(utf16.startIndex, offsetBy: range.location, limitedBy: utf16.endIndex) else { return nil }
        guard let to16 = utf16.index(from16, offsetBy: range.length, limitedBy: utf16.endIndex) else { return nil }
        guard let from = String.Index(from16, within: self) else { return nil }
        guard let to = String.Index(to16, within: self) else { return nil }
        return from ..< to
    }
}

3.10 自动获取焦点(默认让键盘弹起)

swift

textField.becomeFirstResponder()

OC

[textField becomeFirstResponder];