iOS开发初级（一、基础003）

输入框：UITextField和UITextView
应用场景：登录或文本输入时使用
代码：

    //UITextField
    UITextField *textField = [[UITextField alloc]initWithFrame:CGRectMake(30.0, 80.0, 160.0, 30.0)];
    //提示文字
    textField.placeholder = @"请输入数字";
    //输入键盘类型
    textField.keyboardType = UIKeyboardTypeNumberPad;//数字
    //添加到父视图
    [self.view addSubview:textField];

常用遵循协议<UITextFieldDelegate>：

@protocol UITextFieldDelegate <NSObject>

@optional

- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField;        // return NO to disallow editing.
- (void)textFieldDidBeginEditing:(UITextField *)textField;           // became first responder
- (BOOL)textFieldShouldEndEditing:(UITextField *)textField;          // return YES to allow editing to stop and to resign first responder status. NO to disallow the editing session to end
- (void)textFieldDidEndEditing:(UITextField *)textField;             // may be called if forced even if shouldEndEditing returns NO (e.g. view removed from window) or endEditing:YES called
- (void)textFieldDidEndEditing:(UITextField *)textField reason:(UITextFieldDidEndEditingReason)reason NS_AVAILABLE_IOS(10_0); // if implemented, called in place of textFieldDidEndEditing:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string;   // return NO to not change text

- (BOOL)textFieldShouldClear:(UITextField *)textField;               // called when clear button pressed. return NO to ignore (no notifications)
- (BOOL)textFieldShouldReturn:(UITextField *)textField;              // called when 'return' key pressed. return NO to ignore.

@end

开发中最常用的：

-(void)textFieldDidEndEditing:(UITextField *)textField{
    NSString *text = textField.text;
    NSLog(@"编辑框文本：%@",text);
}

UITextView和UITextField相似，但不同的是：
UITextView是多行文本输入框，UITextField为单行文本输入框。