Question

我的视图中有两个UIPickerViews和两个UILabel，UIPickerViews中填充了NSMutableArray中的数字。

拣货员需要将选定的值发送到指定的标签。例如：

_pickerView1（已选中“18”） _pickerOutputLabel1（显示“18”）

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

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

我尝试过几件事，但我无法弄清楚如何让它发挥作用。

这是代码（我删除了我解决问题的尝试，因此至少编译：）

//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

//实施文件

#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

我正在尝试3天而且我被困住了。

提前致谢。

Answer 1

在UIPickerView委托方法中，您已将pickerView参数命名为“_pickerView1”。命名该参数与实例变量相同意味着仅为该选择器调用委托方法。它只是调用委托方法的任何选择器的本地名称。

由于您已将两个选择器的委托都设置为自己，因此两个选择器都调用相同的方法。

要告诉哪个选择器正在拨打电话，有两种方法：

在创建每个标记时为每个标记值设置不同的标记值，并检查委托方法中的标记（例如_pickerView1.tag = 1;和委托方法：if (pickerView.tag == 1)...）
< / LI>

或者，直接与实例变量进行比较。例如：

- (void)pickerView:(UIPickerView *)pickerView //<-- std name as in doc
            didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
    if (pickerView == _pickerView1)
          // Above:
          //   "pickerView" is the picker in which a row was selected
          //   "_pickerView1" is the actual instance variable
        _pickerOutputLabel1.text = [nrArray objectAtIndex:row];
    else
        _pickerOutputLabel2.text = [nrArray objectAtIndex:row];
}

此外，您在控件声明前面有IBOutlet，但之后以编程方式创建它们。如果您使用Interface Builder来创建控件，请不要在代码中重新创建它们。如果您不使用IB，请删除IBOutlet。

Answer 2

你也可以用这个： - （void）pickerView：（UIPickerView *）pickerView didSelectRow：（NSInteger）row inComponent：（NSInteger）component {

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



if( [pickerView isEqual: pickerAnother ]){

    secondstr = [secondArray objectAtIndex:row];


}

}

2个UIPickerViews都有自己的UILabel来显示来自NSMutableArray的值

2 个答案: