学习iOS控件之UITextField

学习iOS控件之UITextField

UITextField是一个文本输入框，可以输入字母，数字等。

UITextField的官网地址:https://developer.apple.com/reference/uikit/uitextfield 点击打开链接

    //初始化    UITextField *textField = [[UITextField alloc] init];        //设置背景色    textField.backgroundColor = [UIColor redColor];        //设置frame    textField.frame = CGRectMake(50, 50, 300, 50);        //设置字体大小    textField.font = [UIFont systemFontOfSize:15];        //设置文本颜色    textField.textColor = [UIColor blueColor];        //在没有输入的情况，显示的文字    textField.placeholder = @"请输入内容";        /*     右边的小叉     UITextFieldViewModeNever,          从不显示     UITextFieldViewModeWhileEditing,   编辑是现实(用的最多)     UITextFieldViewModeUnlessEditing,  编辑时不现实     UITextFieldViewModeAlways          总是现实     */    textField.clearButtonMode = UITextFieldViewModeAlways;        /*    NSTextAlignmentLeft      = 0,    // Visually left aligned   居左对齐    NSTextAlignmentCenter    = 1,    // Visually centered       居中对齐    NSTextAlignmentRight     = 2,    // Visually right aligned  居右对齐        NSTextAlignmentJustified = 3,    // Fully-justified. The last line in a paragraph is natural-aligned.    NSTextAlignmentNatural   = 4,    // Indicates the default alignment for script  默认对齐，居左    */    //对齐方式    textField.textAlignment = NSTextAlignmentJustified;        //设置左边视图    UIButton *overlayButton = [UIButton buttonWithType:UIButtonTypeCustom];    [overlayButton setImage:[UIImage imageNamed:@"bookmark"] forState:UIControlStateNormal];    [overlayButton addTarget:self action:@selector(displayBookmarks:)            forControlEvents:UIControlEventTouchUpInside];    overlayButton.frame = CGRectMake(0, 0, 28, 28);    textField.leftView = overlayButton;        /*     UIKeyboardTypeDefault,                // Default type for the current input method. 默认     UIKeyboardTypeASCIICapable,           // Displays a keyboard which can enter ASCII characters ASCII码     UIKeyboardTypeNumbersAndPunctuation,  // Numbers and assorted punctuation. 数组和符号     UIKeyboardTypeURL,                    // A type optimized for URL entry (shows . / .com prominently).     UIKeyboardTypeNumberPad,              // A number pad with locale-appropriate digits (0-9, ۰-۹, ०-९, etc.). Suitable                          for PIN entry.  数字键盘     UIKeyboardTypePhonePad,               // A phone pad (1-9, *, 0, #, with letters under the numbers). 电话键盘     UIKeyboardTypeNamePhonePad,           // A type optimized for entering a person's name or phone number. 和默认一样     UIKeyboardTypeEmailAddress,           // A type optimized for multiple email address entry (shows space @ . prominently).     UIKeyboardTypeDecimalPad NS_ENUM_AVAILABLE_IOS(4_1),   // A number pad with a decimal point. 数字和点     UIKeyboardTypeTwitter NS_ENUM_AVAILABLE_IOS(5_0),      // A type optimized for twitter text entry (easy access to @ #)     UIKeyboardTypeWebSearch NS_ENUM_AVAILABLE_IOS(7_0),    // A default keyboard type with URL-oriented addition (shows space . prominently).     UIKeyboardTypeASCIICapableNumberPad NS_ENUM_AVAILABLE_IOS(10_0), // A number pad (0-9) that will always be ASCII digits.          UIKeyboardTypeAlphabet = UIKeyboardTypeASCIICapable, // Deprecated 废弃          */    textField.keyboardType = UIKeyboardTypeNumberPad;        [self.view addSubview:textField];

代理的方法:

// return NO to disallow editing./** 是否允许编辑 @param textField textField description @return YES:允许编辑   NO:不想允许编辑 */- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField{    return YES;}// became first responder/** 开始编辑 @param textField textField description */- (void)textFieldDidBeginEditing:(UITextField *)textField{    }// return YES to allow editing to stop and to resign first responder status. NO to disallow the editing session to end/** 结束编辑 @param textField textField description @return YES:允许结束编辑  NO:不允许借宿编辑 */- (BOOL)textFieldShouldEndEditing:(UITextField *)textField{    return YES;}// may be called if forced even if shouldEndEditing returns NO (e.g. view removed from window) or endEditing:YES called/** 结束编辑时调用 @param textField textField description */- (void)textFieldDidEndEditing:(UITextField *)textField{    }// if implemented, called in place of textFieldDidEndEditing://textFieldDidEndEditing需要替换- (void)textFieldDidEndEditing:(UITextField *)textField reason:(UITextFieldDidEndEditingReason)reason NS_AVAILABLE_IOS(10_0){    }// return NO to not change text/** 是否改变文本内容 @param textField textField description @param range range description @param string string description @return YES */- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{    return YES;}// called when clear button pressed. return NO to ignore (no notifications)/** 按下clear时调用 @param textField textField description @return YES:调用   NO:不调用 */- (BOOL)textFieldShouldClear:(UITextField *)textField{    return YES;}// called when 'return' key pressed. return NO to ignore./** 按下return时调用 @param textField textField description @return YES:调用  NO:不调用 */- (BOOL)textFieldShouldReturn:(UITextField *)textField{    return YES;}