2 个 UIPickerViews，每个都有自己的 UILabel 来显示 NSMutableArray 中的值

Question

我的视图中有 2 个 UIPickerViews 和两个 UILabels，并且 UIPickerViews 填充有 NSMutableArray 中的数字。

选择器需要将选择的值发送到分配的标签。示例：

_pickerView1（选择“18”） _pickerOutputLabel1（显示“18”）

_pickerView2（选择“7”） _pickerOutputLabel2（显示“7”）

我无法正常工作，_pickerView2 还将其值发送到 _pickerOutputLabel1 而不是 _pickerOutputLabel2。

我尝试了一些方法，但我不知道如何让它发挥作用。

这是代码（我删除了修复问题的尝试，因此它至少可以编译:)

//头文件

#import <UIKit/UIKit.h>



@interface UIPickerViewAndLabelsViewController : UIViewController <UIPickerViewDelegate, UIPickerViewDataSource> {


NSMutableArray *nrArray;
IBOutlet UIPickerView *_pickerView1;
IBOutlet UIPickerView *_pickerView2;

UILabel *_pickerOutputLabel1;
    UILabel *_pickerOutputLabel2;

}
@property (nonatomic, retain) IBOutlet UIPickerView *pickerView1;
@property (nonatomic, retain) IBOutlet UIPickerView *pickerView2;
@property (nonatomic, retain) IBOutlet UILabel *pickerOutputLabel1;
@property (nonatomic, retain) IBOutlet UILabel *pickerOutputLabel2;
@end

//实现文件

#import "UIPickerViewAndLabelsViewController.h"

@implementation UIPickerViewAndLabelsViewController

@synthesize pickerView1 = _pickerView1;
@synthesize pickerView2 = _pickerView2;
@synthesize pickerOutputLabel1 = _pickerOutputLabel1;
@synthesize pickerOutputLabel2 = _pickerOutputLabel2;

/*
// The designated initializer. Override to perform setup that is required before the view is loaded.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}
*/


// Implement loadView to create a view hierarchy programmatically, without using a nib.
/*
- (void)loadView {
}
*/



// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {

_pickerOutputLabel1 = [[UILabel alloc]initWithFrame:CGRectMake(400, 120, 50, 50)];
[self.view addSubview:_pickerOutputLabel1];

_pickerOutputLabel2 = [[UILabel alloc]initWithFrame:CGRectMake(400, 320, 50, 50)];
[self.view addSubview:_pickerOutputLabel2];

nrArray = [[NSMutableArray alloc] init];

for (int i=0;i<20+1;i++) {

    [nrArray addObject:[NSString stringWithFormat:@"%d", i]];
}



_pickerView1 = [[UIPickerView alloc] initWithFrame:CGRectMake(500, 120, 100, 162)];


_pickerView1.delegate = self;
_pickerView1.dataSource = self;
_pickerView1.showsSelectionIndicator = YES;
_pickerView1.transform = CGAffineTransformMakeScale(0.8, 0.8);
[self.view addSubview:_pickerView1];
[_pickerView1 release];
[_pickerView1 selectRow:0 inComponent:0 animated:NO];

_pickerOutputLabel1.text = [nrArray objectAtIndex:[_pickerView1 selectedRowInComponent:0]];


_pickerView2 = [[UIPickerView alloc] initWithFrame:CGRectMake(500, 320, 100, 162)];


_pickerView2.delegate = self;
_pickerView2.dataSource = self;
_pickerView2.showsSelectionIndicator = YES;
_pickerView2.transform = CGAffineTransformMakeScale(0.8, 0.8);
[self.view addSubview:_pickerView2];
[_pickerView2 release];
[_pickerView2 selectRow:0 inComponent:0 animated:NO];

_pickerOutputLabel2.text = [nrArray objectAtIndex:[_pickerView2 selectedRowInComponent:0]];


    [super viewDidLoad];
}







- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)_pickerView1;
{
    return 1;
}


- (void)pickerView:(UIPickerView *)_pickerView1 didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
    _pickerOutputLabel1.text=    [nrArray objectAtIndex:row];
}

- (NSInteger)pickerView:(UIPickerView *)_pickerView1 numberOfRowsInComponent:(NSInteger)component;
{
    return [nrArray count];
}

- (NSString *)pickerView:(UIPickerView *)_pickerView1 titleForRow:(NSInteger)row forComponent:(NSInteger)component;
{
    return [nrArray objectAtIndex:row];

}








// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    return YES;
}

- (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

我尝试了 3 天，但我被卡住了。

提前致谢。

Answer 1

在 UIPickerView 委托方法中，您将 pickerView 参数命名为“_pickerView1”。将该参数命名为与实例变量相同并不意味着只会为该选择器调用委托方法。它只是成为任何选择器调用委托方法的本地名称。

由于您已将两个选择器的委托设置为 self，因此两个选择器都调用相同的方法。

要判断哪个选择器正在进行调用，有几种方法：

• 在创建它们时为每个选择器设置不同的标记值，并在委托方法中检查标记（例如。_pickerView1.tag = 1;< /code> 并在委托方法中： if (pickerView.tag == 1)... )

• 或者，比较直接针对实例变量。例如：

  - (void)pickerView:(UIPickerView *)pickerView //<-- 文档中的 std 名称
              didSelectRow:(NSInteger)行 inComponent:(NSInteger)组件
  {
      if (pickerView == _pickerView1)
            // 多于：
            // “pickerView”是选择行的选择器
            // “_pickerView1”是实际的实例变量
          _pickerOutputLabel1.text = [nrArray objectAtIndex:row];
      别的
          _pickerOutputLabel2.text = [nrArray objectAtIndex:row];
  }
  

另外，您可以在控件声明前面添加 IBOutlet，然后以编程方式创建它们。如果您使用 Interface Builder 创建控件，请勿在代码中重新创建它们。如果您不使用 IB，请删除 IBOutlet。

Answer 2

你也可以使用这个：
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)行 inComponent:(NSInteger)组件
{

if( [pickerView isEqual: picker ]){
    firststr = [firstArray objectAtIndex:row];
}



if( [pickerView isEqual: pickerAnother ]){

    secondstr = [secondArray objectAtIndex:row];


}

}