UIDatePicker

目的：點選按鈕出現日期選單，選完日期後顯示在畫面

  

step1. 畫面加入“button”及“label”元件

step2. ViewController.h 
@interface ViewController : UIViewController
{
    IBOutlet id mylab;
}
-(IBAction)onClick:(id)sender;
@end


step3. ViewController.m
-(IBAction)onClick:(id)sender{
    //產生UIDatePicker物件，並初始化其出現座標及長寬
    UIDatePicker *picker = [[UIDatePicker alloc] initWithFrame:CGRectMake(0, 224, 320, 216)];
    //設定日期模式
    [picker setDatePickerMode:UIDatePickerModeDateAndTime];
    //加入事件方法
    [picker addTarget:self action:@selector(changedValue:) forControlEvents:UIControlEventValueChanged];
    //畫面上加上此控件
    [self.view addSubview:picker];
   
}
-(void)changedValue:(UIDatePicker *)sender {
    //日期格式
    NSDateFormatter *format = [[NSDateFormatter alloc]init];
    [format setDateFormat:@"yyyy/MM/dd HH:mm"];
    //取得日期轉換成NSString
    NSString *str = [format stringFromDate:[sender date]];
    [mylab setText:str];
}