@protocol UIPickerViewDataSource, UIPickerViewDelegate;

 @interface UIPickerView : UIView <NSCoding>

 @property(nonatomic,assign) id<UIPickerViewDataSource> dataSource; // default is nil,设置代理

 @property(nonatomic,assign) id<UIPickerViewDelegate>   delegate;  // default is nil，设置代理

 @property(nonatomic)  BOOL showsSelectionIndicator;    // default is NO

 @property(nonatomic,readonly) NSInteger numberOfComponents; //列数

二、协议UIPickerViewDataSource

@protocol UIPickerViewDataSource<NSObject>

@required //必须要实现的方法

// 返回的列显示的数量。

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

//返回行数在每个组件(每一列)

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

@end

三、协议UIPickerViewDelegate

@protocol UIPickerViewDelegate<NSObject>

@optional //可以选择执行的方法

//每一列组件的列宽度

- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component;

//每一列组件的行高度

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

// 返回每一列组件的每一行的标题内容

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

// 返回每一列组件的每一行的标题内容的属性

- (NSAttributedString *)pickerView:(UIPickerView *)pickerView attributedTitleForRow:(NSInteger)row forComponent:(NSInteger)component;

// 返回每一列组件的每一行的视图显示

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

//执行选择某列某行的操作

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

@end

1 #import <UIKit/UIKit.h>
2 
3 @interface ViewController : UIViewController<UIPickerViewDataSource,UIPickerViewDelegate>
4 @property(nonatomic,strong)NSArray *years;
5 @property(nonatomic,strong)NSArray *months;
6 @property(nonatomic,strong)NSArray *days;
7 
8 @end

  View Code

演示二：制作简单的字体表,包括字体类型、大小、颜色

源码如下：

1 #import <UIKit/UIKit.h>
2 
3 @interface ViewController : UIViewController<UIPickerViewDataSource,UIPickerViewDelegate>
4 @property(nonatomic,strong) NSArray *fontNames;
5 @property(nonatomic,strong) NSArray *fontSizes;
6 @property(nonatomic,strong) NSArray *fontColors;
7 @end

  View Code

演示三：制作简单的图库浏览器

源码如下：

#import <UIKit/UIKit.h>
@interface ViewController : UIViewController<UIPickerViewDelegate,UIPickerViewDataSource>
@end

  View Code