1.UIPickerView的寬度和高度是固定的,縱向是320*216,橫向是568*162 2.屬性: @property(nonatomic,readonly)NSInteger numberOfComponents; // 選擇框的行數 @property(nonatomic,assign)idUIPickerViewDataSource> dataSource; (類似于UITableView) @property(nonatomic,assign)idUIPickerViewDelegate>delegate; (類似于UITableView) (BOOL)showsSelectionIndicator// 是否顯示選擇指示器?,即是一個藍色的條 ~~~ pickerView = [[UIPickerView alloc] initWithFrame:CGRectMake(0, 0, 320, 216)]; // 指定Delegate pickerView.delegate=self; // 顯示選中框 pickerView.showsSelectionIndicator=YES; [self.view addSubview:pickerView]; ~~~ 以上可以在視圖顯示一個選取器，但是內容空白，pickerView.showsSelectionIndicator=YES;是這只當前選取器所選中的內容： 選取器上顯示數據，必須依賴兩個協議，UIPickerViewDelegate和UIPickerViewDataSource，把他們添加到ViewController.h文件中 ~~~ #import <UIKit/UIKit.h> @interface ViewController : UIViewController<UIPickerViewDelegate,UIPickerViewDataSource> { UIPickerView *pickerView; NSArray *pickerData; } @end ~~~ 3.然后在.m文件的ViewDidLoad中初始化界面 ~~~ - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. pickerView = [[UIPickerView alloc] initWithFrame:CGRectMake(0, 0, 320, 216)]; // 指定Delegate pickerView.delegate=self; // 顯示選中框 pickerView.showsSelectionIndicator=YES; [self.view addSubview:pickerView]; NSArray *dataArray = [[NSArray alloc]initWithObjects:@"許嵩",@"周杰倫",@"梁靜茹",@"許飛",@"鳳凰傳奇",@"阿杜",@"方大同",@"林俊杰",@"胡夏",@"邱永傳", nil]; pickerData=dataArray; // 添加按鈕 CGRect frame = CGRectMake(120, 250, 80, 40); UIButton *selectButton = [UIButton buttonWithType:UIButtonTypeRoundedRect]; selectButton.frame=frame; [selectButton setTitle:@"SELECT" forState:UIControlStateNormal]; [selectButton addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:selectButton]; } ~~~ 4.實現UIPickerView的代理方法，將數據顯示在選取器上所需要幾個方法 ~~~ #pragma mark - #pragma mark Picker Date Source Methods //返回顯示的列數 -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView { return 1; } //返回當前列顯示的行數 -(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component { return [pickerData count]; } #pragma mark Picker Delegate Methods //返回當前行的內容,此處是將數組中數值添加到滾動的那個顯示欄上 -(NSString*)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component { return [pickerData objectAtIndex:row]; } ~~~ 前兩個是數據源的代理方法，一個是返回列，有幾個選取器就返回幾，第二個是設置選取器有多少行，因為就這一個選取器，所以直接返回行數，即數組元素個數多少；第三個代理方法是將數組元素添加到了選取器上面顯示； 說一下兩個協議實例方法,參考[http://www.cnblogs.com/edsioon/](http://www.cnblogs.com/edsioon/) ? ?UIPickerViewDelegate[中的實例方法](http://www.cnblogs.com/edsioon/archive/2012/03/27/2418914.html) ? ?//?當用戶選擇某個row時 ? - (void) pickerView: (UIPickerView *)pickerView?didSelectRow: (NSInteger)row inComponent: ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? (NSInteger)component // 當其在繪制row內容,需要row的高度時 - (CGFloat) pickerView:(UIPickerView *)pickerView?rowHeightForComponent: (NSInteger) component // 返回指定component.row顯示的文本 - (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger) component //?當picker view需要給指定的component.row指定view時,調用此函數.返回值為用作row內容的view - (UIView *)pickerView: (UIPickerView *)pickerView view ForRow:(NSInteger) row forComponent:(NSInteger) component reusingView:(UIView *) view // row的寬度 - (CGFloat)pickerView: (UIPickerView *)pickerView?widthForComponent:(NSInteger) component [UIPickerViewDataSource](http://www.cnblogs.com/edsioon/archive/2012/03/27/2418919.html)[中的實例方法](http://www.cnblogs.com/edsioon/archive/2012/03/27/2418919.html) 按照官方文檔的說法,UIPickerViewDataSource這個協議僅有的功能就是提供picker view中component的個數和各個component中的row的個數,雖然名為datasource,但是它工作于MVC的C中 本協議僅有兩個實例方法,均需要實現: // 返回列數 - (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView // 返回每一列對應的行數 - (NSInteger) pickerView:(UIPickerView *) pickerView?numberOfRowsInComponent:(NSInteger) component 5.關于按鈕響應事件，關于按鈕的形成和添加響應事件不再提，前面都有， ~~~ (void) buttonPressed:(id)sender { NSInteger row =[pickerView selectedRowInComponent:0]; NSString *selected = [pickerData objectAtIndex:row]; NSString *message = [[NSString alloc] initWithFormat:@"你選擇的是:%@",selected]; UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示" message:message delegate:self cancelButtonTitle:@"OK" otherButtonTitles: nil]; [alert show]; } ~~~ @UIPickerView還有其他實例方法 // 獲取指定列的行數 -?(NSInteger)?numberOfRowsInComponent:(NSInteger)component // 刷新所有的列 - (void)?reloadAllComponents // 刷新指定的列 - (void)?reloadComponent: (NSInteger) component - (CGSize)?rowSizeForComponent: (NSInteger) component // 獲取某列選擇的行數 - (NSInteger)?selectedRowInComponent: (NSInteger) component // 選擇一行 - (void)?selectRow: (NSInteger)row inComponent: (NSInteger)component animated: (BOOL)animated - (UIView *)?viewForRow: (NSInteger)row forComponent: (NSInteger)component 附上源代碼:?[http://download.csdn.net/detail/duxinfeng2010/4410909](http://download.csdn.net/detail/duxinfeng2010/4410909)