iOS开发 UIPickerView的使用

先看效果图：

请无视下面的tab Bar,下面的代码跟它无关。
第一步，在xib文件添加一个UIPickerView,和一个Round Rect Button,如图上所示。
第二步，在编辑UI的窗口中，选中UIPickerView，打开Connection　inspector，按住Control键，分别拖动dataSource和delegate右边的小圈到左边Placeholders下的File’s Owner,建立连接。
第三步，按住control键，拖动UIPickerView到ViewController.h文件中，创建outlet,同样的方法为按钮创建action
viewController.h代码如下:

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#import <UIKit/UIKit.h>   #define kFillingComponent 0 #define kBreadComponent 1 @interface DoubleComponentPickerViewController : UIViewController <UIPickerViewDelegate,UIPickerViewDataSource> //必须添加这两个协议 @property (strong, nonatomic) IBOutlet UIPickerView *doublePickers; @property (strong,nonatomic) NSArray *fillingTypes; @property (strong,nonatomic) NSArray *breadTypes; //两个array用于存储两个选择器的选项 - (IBAction)buttonPressed; @end

viewController.m内容如下：

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#import "DoubleComponentPickerViewController.h"   @implementation DoubleComponentPickerViewController @synthesize doublePickers; @synthesize fillingTypes=_fillingTypes,breadTypes=_breadTypes;   - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; if (self) { // Custom initialization } return self; }   - (void)viewDidLoad { [super viewDidLoad]; NSArray *fillingArray=[[NSArray alloc] initWithObjects:@"aaa",@"bbb",@"ccc",@"ddd", nil]; _fillingTypes=fillingArray; NSArray *breadArray=[[NSArray alloc] initWithObjects:@"111",@"222",@"333",@"444", nil]; _breadTypes=breadArray; //启动时载入数组 }   - (void)viewDidUnload { [self setDoublePickers:nil]; [super viewDidUnload]; _fillingTypes=nil; _breadTypes=nil; //关闭时清空 // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; }   - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { // Return YES for supported orientations return (interfaceOrientation == UIInterfaceOrientationPortrait); }   - (IBAction)buttonPressed { NSInteger * fillingRow=[doublePickers selectedRowInComponent:kFillingComponent]; NSInteger * breadRow=[doublePickers selectedRowInComponent:kBreadComponent]; NSString *string=[NSString stringWithFormat:@"%@ %@",[_fillingTypes objectAtIndex:fillingRow],[_breadTypes objectAtIndex:breadRow]]; NSLog(@"%@",string); //读取选择的结果   } //下面的方法都是协议中定义的 -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView { return 2; //定义选择器数量 } -(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component { if(component==kBreadComponent) return [_breadTypes count]; return [_fillingTypes count]; //选项数量 } -(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {   if(component==kBreadComponent)   return [_breadTypes objectAtIndex:row];   return [_fillingTypes objectAtIndex:row]; //选项的文字   } @end

如果只要一个选择器，更简章，稍做修改就可实现。