UIPickerView是iOS中的原生选择器控件，使用方便，用法简单，效果漂亮。

@property(nonatomic,assign) id<UIPickerViewDataSource> dataSource;

@property(nonatomic,assign) id<UIPickerViewDelegate>   delegate;

设置数据源和代理

@property(nonatomic) BOOL showsSelectionIndicator;

是否显示选择框，在iOS7之后这个属性没有任何效果

@property(nonatomic,readonly) NSInteger numberOfComponents;

获取分区数

- (NSInteger)numberOfRowsInComponent:(NSInteger)component;

获取某一分区的行数

- (CGSize)rowSizeForComponent:(NSInteger)component;

获取某一分区行的尺寸

- (UIView *)viewForRow:(NSInteger)row forComponent:(NSInteger)component;

获取某一分区某一行的视图

- (void)reloadAllComponents;

重载所有分区

- (void)reloadComponent:(NSInteger)component;

重载某一分区

- (void)selectRow:(NSInteger)row inComponent:(NSInteger)component animated:(BOOL)animated;

设置选中某一分区某一行

- (NSInteger)selectedRowInComponent:(NSInteger)component;

返回某一分区选中的行

数据源代理中的方法：

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

设置分区数

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

根据分区设置行数

代理中的方法：

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

设置分区宽度

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

设置分区行高

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

设置某一行显示的标题

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

通过属性字符串设置某一行显示的标题

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

设置某一行显示的view视图

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

选中某一行时执行的回调