如何在一个 ViewController 中同时拥有两个 UIPickerViews？答案

【问题标题】：How to have two UIPickerViews together in one ViewController?如何在一个 ViewController 中同时拥有两个 UIPickerViews？
【发布时间】：2011-01-08 03:35:28
【问题描述】：

我正在尝试将 2 个 UIPickerViews 放在一个 ViewController 中。每个UIPickerView 都有不同的数据数组。我正在使用界面生成器来链接选择器。我知道我必须使用单独的委托和数据源，但我似乎无法正确地将所有内容与界面构建器连接起来。这是我所有的代码：

pickerTesting.h

#import <UIKit/UIKit.h>
#import "picker2DataSource.h"

@interface pickerTestingViewController : UIViewController <UIPickerViewDelegate, UIPickerViewDataSource>{

IBOutlet UIPickerView *picker;
IBOutlet UIPickerView *picker2;
NSMutableArray  *pickerViewArray;
}

@property (nonatomic, retain) IBOutlet UIPickerView *picker;
@property (nonatomic, retain) IBOutlet UIPickerView *picker2;
@property (nonatomic, retain) NSMutableArray *pickerViewArray;
@end

pickerTesting.m

#import "pickerTestingViewController.h"

@implementation pickerTestingViewController

@synthesize picker, picker2, pickerViewArray;


- (void)viewDidLoad
 {
[super viewDidLoad];
pickerViewArray = [[NSMutableArray alloc] init];

[pickerViewArray addObject:@" 100 "];
[pickerViewArray addObject:@" 200 "];
[pickerViewArray addObject:@" 400 "];
[pickerViewArray addObject:@" 600 "];
[pickerViewArray addObject:@" 1000 "];

[picker selectRow:1 inComponent:0 animated:NO];
picker2.delegate = self;
picker2.dataSource = self;
}

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)picker;
{
return 1;
}

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

}

- (NSInteger)pickerView:(UIPickerView *)picker numberOfRowsInComponent:(NSInteger)component;
{
return [pickerViewArray count];

}

- (NSString *)pickerView:(UIPickerView *)picker titleForRow:(NSInteger)row forComponent:(NSInteger)component;
{
return [pickerViewArray objectAtIndex:row];
}

- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];

// Release any cached data, images, etc that aren't in use.
 }

- (void)viewDidUnload
{
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}


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


@end

我为其他数据源设置了一个单独的类。

picker2DataSource.h

@interface picker2DataSource : NSObject <UIPickerViewDataSource, UIPickerViewDelegate>
{
NSMutableArray  *customPickerArray;
}

@property (nonatomic, retain) NSMutableArray *customPickerArray;

@end

picker2DataSource.m

#import "picker2DataSource.h"


@implementation picker2DataSource
@synthesize customPickerArray;

- (id)init
{
// use predetermined frame size
self = [super init];
if (self)
{
    customPickerArray = [[NSMutableArray alloc] init];

    [customPickerArray addObject:@" a "];
    [customPickerArray addObject:@" b "];
    [customPickerArray addObject:@" c "];
    [customPickerArray addObject:@" d "];
    [customPickerArray addObject:@" e "];


}
return self;

}

- (void)dealloc
{
[customPickerArray release];
[super dealloc];
}

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)picker2;
{
return 1;
}

- (void)pickerView:(UIPickerView *)picker2 didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{

}

- (NSInteger)pickerView:(UIPickerView *)picker2 numberOfRowsInComponent:(NSInteger)component;
{
return [customPickerArray count];

}

- (NSString *)pickerView:(UIPickerView *)picker2 titleForRow:(NSInteger)row forComponent:(NSInteger)component;
{
return [customPickerArray objectAtIndex:row];
}

@end

任何帮助或代码示例都会很棒。谢谢。

【问题讨论】：

标签： iphone objective-c cocoa-touch uikit uipickerview

【解决方案1】：

使用 Interface Builder，将两个 UIPickerView 的标签属性分别设置为 1 和 2。然后，在每个委托方法中，使用 if 语句检查 UIPickerView 参数的标签。

【讨论】：

【解决方案2】：

UIPickerViewDataSource 方法怎么样

//这将返回要显示的“列”数。

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

return 2;

}

【讨论】：