时间处理控件UIDatePicker与UIPickerView

UIDatePicker依然继承自UIControl是经常用到的一个时间控件，方便我们用户输入日期.

让控制器监听值发生改变

#import <UIKit/UIKit.h>

@interface cooljuneViewController :UIViewController <UIPickerViewDataSource,UIPickerViewDelegate>

- (IBAction)dateChange:(UIDatePicker *)sender;

@property (weak, nonatomic) IBOutletUILabel *dateLable;

@property (weak, nonatomic) IBOutletUITextField *nameFiled;

@end

- (IBAction)dateChange:(UIDatePicker *)sender {

   NSDate *date= sender.date;

    NSDateFormatter *format=[[NSDateFormatteralloc]init];

    format.dateFormat=@"yyyy-MM-dd hh:mm:ss";

    //时间转字符串输出

   self.dateLable.text=[formatstringFromDate:date];

    UIDatePicker *picker=[[UIDatePickeralloc]init];

    //设置显示格式

    picker.datePickerMode=UIDatePickerModeDate;

    //设置地区

    picker.locale=[[NSLocalealloc]initWithLocaleIdentifier:@"zh_cn"];

    //设置默认显示时间

    picker.date

}

UIPickerView用于像datePicker一样滚动显示内容，多用于下拉选项，很多html中的select，而UIPickerView中可以显示字符串内容也可以显示其他组件view如图片view，Buttonview等,而如果要使用 UIPickerView必须实现UIPickerViewDataSource,UIPickerViewDelegate这两个协议，当控制器加载完成后，显示UIPickerView上面的内容会通过代理取获取内容，这个时候控制器就充当了代理，UIPickerViewDataSource提供数据来源，UIPickerViewDelegate获取内容以及监听发生变化。

#import <UIKit/UIKit.h>

@interface cooljuneViewController :UIViewController<UIPickerViewDataSource,UIPickerViewDelegate>

@end

#import "cooljuneViewController.h"

@interface cooljuneViewController ()

@property(nonatomic,strong)NSArray *firstCol;

@property(nonatomic,strong)NSArray *secondCol;

@end

@implementation cooljuneViewController

- (void)viewDidLoad

{

    [superviewDidLoad];

self.firstCol=@[@"test",@"yte",@"fsd",@"55"];

    self.secondCol=@[@"hh",@"ff",@"gg",@"kk"];

}

#pragma mark - 数据源方法

//返回第component列的行数

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

   return component==0?self.firstCol.count:self.secondCol.count;

}

#pragma mark 返回列数

-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{

   return2;

}

//第component列内容

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

    

   if(component==0){

       returnself.firstCol[row];

    }else{

       returnself.secondCol[row];

    }

}

//选中某一行发生改变

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

   if(component==0){

        

       NSString *left=self.firstCol[row];

        

        //根据传入列数返回显示的行数

       int rightRow=[pickerViewselectedRowInComponent:1];

        

       NSString *right=self.secondCol[rightRow];

        

       NSLog(@"first=%@,secoden-%@",left,right);

    }else{

       NSString *right=self.secondCol[row];

       int leftRow=[pickerViewselectedRowInComponent:0];

       NSString *left=self.firstCol[leftRow];

       NSLog(@"%@-%@",left,right);

    }

}

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

   UIView *flagView=[[UIViewalloc]init];

   CGFloat viewHeight=40;

   CGFloat viewWidth=200;

    flagView.bounds=CGRectMake(0,0, viewWidth, viewHeight);

    

   NSDictionary *dict=self.flags[row];

    //国家名称

   UILabel *label=[[UILabelalloc]init];

   CGFloat lableWith=120;

    label.frame=CGRectMake(0,0, lableWith, viewHeight);

    label.text=dict[@"name"];

    label.textAlignment=NSTextAlignmentCenter;

    label.backgroundColor=[UIColorclearColor];

    [flagViewaddSubview:label];

   //图片

   UIImageView *imageView=[[UIImageViewalloc]init];

    imageView.frame=CGRectMake(lableWith,0, viewWidth-lableWith, viewHeight);

    

    imageView.image=[UIImageimageNamed:dict[@"icon"]];

    [flagViewaddSubview:imageView];

   return flagView;

}

//修改每一行的高度

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

   return40;

}

总结常用方法（实现自协议里面的方法）：

UIPickerViewDataSource协议

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView; 返回总列数

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component; 返回第component列的行数

UIPickerViewDelegate协议

- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component; 修改列宽度

- (CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component; 修改行高

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

返回第component列第row行显示的字符串内容

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

返回第component列第row行显示的view内容

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

获取选中行的值