iPhone开发【六】常用控件之Picker View

转载请注明出处，原文网址：http://blog.csdn.net/m_changgong/article/details/8112404 作者：张燕广

实现的功能：演示Picker View的使用方法

关键词：Picker View

1、创建一个Single View Application工程，命名为：PickersDemo，如下图

2、修改ViewController.xib，添加一个Picker View和一个Button控件，如下

连接输出口、操作，如下

3、视图控制器ViewController，需要实现协议UIPickerViewDataSource、UIPickerViewDelegate中的必须实现的方法，

在工程目录依次展开Frameworks->UIKit.framework->Headers，然后打开UIPickerView.h，在文件的尾部可以看到协议UIPickerViewDataSource、UIPickerViewDelegate的定义，如下

4、修改ViewController.h：

 //
 //  ViewController.h
 //  PickersDemo
 //
 //  Created by Zhang Yanguang on 12-10-25.
 //  Copyright (c) 2012年 MyCompanyName. All rights reserved.
 //

 #import <UIKit/UIKit.h>
 #define kDeviceCategory 0
 #define kDeviceName 1

 @interface ViewController : UIViewController

 @property(strong,nonatomic)IBOutlet UIPickerView *picker;
 @property(nonatomic,retain)NSDictionary *appleDevices;
 @property(nonatomic,retain)NSArray *deviceCategory;
 @property(nonatomic,retain)NSArray *deviceName;

 -(IBAction)buttonPressed:(id)sender;
 @end

5、修改ViewController.m：

 //
 //  ViewController.m
 //  PickersDemo
 //
 //  Created by Zhang Yanguang on 12-10-25.
 //  Copyright (c) 2012年 MyCompanyName. All rights reserved.
 //

 #import "ViewController.h"

 @interface ViewController ()

 @end

 @implementation ViewController
 @synthesize picker;
 @synthesize appleDevices;
 @synthesize deviceCategory;
 @synthesize deviceName;

 - (void)viewDidLoad
 {
     [super viewDidLoad];
     // Do any additional setup after loading the view, typically from a nib.
     NSArray *array1 = [NSArray arrayWithObjects:@"iPhone",@"iPad",@"iPod",nil];
     NSArray *array2 = [NSArray arrayWithObjects:@"Mac",@"iMac",@"Mac Mini",@"Mac Pro",nil];
     NSDictionary  *dictionary= [NSDictionary dictionaryWithObjectsAndKeys:array1,@"Mobile",array2,@"Computers",nil];//注意用nil结束
     appleDevices = [[NSDictionary alloc]initWithDictionary:dictionary copyItems:YES];

     NSArray *components = [self.appleDevices allKeys];
     NSArray *sorted = [components sortedArrayUsingSelector:@selector(compare:)];
     self.deviceCategory = sorted;

     NSString *selectedCategory = [self.deviceCategory objectAtIndex:0];
     self.deviceName = [self.appleDevices objectForKey:selectedCategory];
 }

 - (void)viewDidUnload
 {
     [super viewDidUnload];
     picker = nil;
     appleDevices = nil;
     deviceCategory = nil;
     deviceName = nil;
     // Release any retained subviews of the main view.
 }

 -(void)dealloc{
     [picker release];
     [appleDevices release];
     [deviceCategory release];
     [deviceName release];
 }

 -(IBAction)buttonPressed:(id)sender{
     NSString *selectedCategory = [self.deviceCategory objectAtIndex:[self.picker selectedRowInComponent:kDeviceCategory]];
     NSString *selectedDevice = [self.deviceName objectAtIndex:[self.picker selectedRowInComponent:kDeviceName]];
     //NSLog(@"%@-%@",selectedCategory,selectedDevice);

     UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"结果" message:[NSString stringWithFormat:@"%@:%@",selectedCategory,selectedDevice]  delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
     [alertView show];
 }

 - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
 {
     return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
 }

 #pragma mark Picker View  DataSource methods
 // returns the number of 'columns' to display.
 - (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{
     return 2;
 }

 // returns the # of rows in each component..
 - (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{
     if(component == kDeviceCategory){
         return [self.deviceCategory count];
     }else{
         return [self.deviceName count];
     }
 }

 #pragma mark Picker View  Delegate methods
 - (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{
     if(component == kDeviceCategory){
         return [self.deviceCategory objectAtIndex:row];
     }else{
         return [self.deviceName objectAtIndex:row];
     }
 }

 - (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{
     if(component == kDeviceCategory){
         NSString *selectedCategory = [self.deviceCategory objectAtIndex:row];
         NSArray *array = [self.appleDevices objectForKey:selectedCategory];
         self.deviceName = array;

         [self.picker selectRow:0 inComponent:kDeviceName animated:YES];
         [self.picker reloadComponent:kDeviceName];
     }
 }

 @end

6、编译、运行，效果如下：

点击下载本文源代码

=========================================================================

以下是我实现的，更为简单的单选择器：

//
//  MyTestViewController.m
//  MyTest
//
//  Created by H3c on 13-1-4.
//  Copyright (c) 2013年.H3c All rights reserved.
//

#import "MyTestViewController.h"

@interface MyTestViewController ()

@end

@implementation MyTestViewController

@synthesize picker;
@synthesize appleDevices;
@synthesize deviceCategory;
@synthesize deviceName;

- (void)viewDidLoad
{
    [super viewDidLoad];
    NSArray *arr1 = [NSArray arrayWithObjects:@"1",@"5",@"7",@"4", nil] ;
    
    // 排序
    NSArray *sorted = [arr1 sortedArrayUsingSelector:@selector(compare:)];
    self.deviceCategory = sorted;
    
    // 设定默认值
    [self.picker selectRow:2 inComponent:0 animated:YES];
}

- (void)viewDidUnload
{
    picker = nil;
    appleDevices = nil;
    deviceCategory = nil;
    deviceName = nil;
    [super viewDidUnload];
}

-(void)dealloc{
    [picker release];
    [appleDevices release];
    [deviceCategory release];
    [deviceName release];
    [super dealloc];
}


- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}

- (IBAction)click:(id)sender
{
    // 获取选中内容
    NSString *selectedCategory = [self.deviceCategory objectAtIndex:[self.picker selectedRowInComponent:0]];
    
    UIAlertView *alertV = [[UIAlertView alloc]initWithTitle:@"Note" message:selectedCategory delegate:self cancelButtonTitle:@"cancel" otherButtonTitles:nil, nil];
    [alertV show];
}

// 列数
-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
    return 1;
}

// 行数
-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    return [self.deviceCategory count];
}

// Cell内容
-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
    return [self.deviceCategory objectAtIndex:row];
}
@end

#import <UIKit/UIKit.h>

#define one  0;

@interface MyTestViewController : UIViewController<UIActionSheetDelegate,UIPickerViewDataSource,UIPickerViewDelegate>

@property(strong,nonatomic)IBOutlet UIPickerView *picker;
@property(nonatomic,retain)NSDictionary *appleDevices;
@property(nonatomic,retain)NSArray *deviceCategory;
@property(nonatomic,retain)NSArray *deviceName;

- (IBAction)click:(id)sender;
@end