1.UIPickerView

(1) UIPickerViewDataSource

• 返回pickerView有多少列

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView

• 返回第component列有多少行

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component

(2) UIPickerViewDelegate

• 返回第component列第row行的标题

- (nullable NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component

• 返回第component列的每一行的行高

- (CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component

• 选中第component列第row行的时候调用

注意：这个方法必须用户主动拖动pickerView，才会调用

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component

• 返回第component列第row行为一个UIView

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(nullable UIView *)view

2.UIDatePicker

• UIDatePicker有默认的尺寸，可以不用设置frame
• 设置地区

picker.locale = [NSLocale localeWithLocaleIdentifier:@"zh"];

• 设置日期的模式

picker.datePickerMode = UIDatePickerModeDate;

• 监听UIDatePicker的滚动

[picker addTarget:self action:@selector(dateChange:) forControlEvents:UIControlEventValueChanged];

• 日期转换字符串

 NSDateFormatter *fmt = [[NSDateFormatter alloc] init];

    fmt.dateFormat = @"yyyy-MM-dd";

    NSString *dateStr = [fmt stringFromDate:datePicker.date];

UITextField

UITextFieldDelegate

• 是否允许开始编辑

- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField

• 是否允许结束编辑

- (BOOL)textFieldShouldEndEditing:(UITextField *)textField

• 是否允许用户输入文字

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

• 文本框开始编辑的时候调用

- (void)textFieldDidBeginEditing:(UITextField *)textField

pch

• 配置pch： buildSetting -> prefix ->
• pch里面的所有内容都是共享，每个文件都会共有:
  • 作用：
    • 1.存放一些公用的宏
    • 2.存放一些公用的头文件
    • 3.自定义Log

获取当前的版本号

 NSString *version = [NSBundle mainBundle].infoDictionary[@"CFBundleShortVersionString"];