我的numberOfComponentsInPickerView：
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
return 3;
}
我的numberOfRowsInComponent：
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
if (component == 0)
return 100;
if (component == 1)
return 100;
if (component == 2)
return 100;
return 0;
}
我的titleForRow是这样的：
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
if (component == 0)
return [NSString stringWithFormat:@"%d", row];
if (component == 1)
return [NSString stringWithFormat:@"%d", row];
if (component == 2)
return [NSString stringWithFormat:@"%d", row];
return 0;
}
我的didSelectRow是这样的 经过编辑后像Paras Joshi所说：
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
int year = [picker selectedRowInComponent:0];
int month = [picker selectedRowInComponent:1];
int day = [picker selectedRowInComponent:2];
if(viewPicker.tag == 1)
labelDate1.text = [year stringByAppendingFormat:@" : %d : %d", month, day];
else
labelDate2.text = [year stringByAppendingFormat:@" : %d : %d", month, day];
}
它仍然给我错误“坏接收器类型'int'”，我仍然不知道如何解决它。我的标签如何从titleForRow获取数据？
年月和日的输入都只是数字（从0到99）所以我写了 - ＆gt; return [NSString stringWithFormat：@“％d”，row];
我没有把我的pickerview的数据放在 - （void）viewDidLoad ，因为我希望我的labelDate1或labelDate2从pickerview获取数据。有没有可能我的标签从像上面写的pickerview获取数据？或者我必须在 - （void）viewDidLoad ？
中写下我的数据任何帮助，谢谢你看我的问题。
答案 0 :(得分：0)
你是否设置了UIPickerView的委托？我的意思是，你的pickerView：didSelectRow：inComponent被调用吗？
答案 1 :(得分：0)
你好@Piyo Piyo你的
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
方法完全错误，您将NSInteger分配给NSString。这就是为什么你得到错误。您应该使用NSArray将数据放入选择器视图行并从此处选择数据。在这里，我将制作一个小样本代码。
这是你的viewController.h文件......
#import <UIKit/UIKit.h>
@interface ViewController : UIViewController<UIPickerViewDelegate, UIPickerViewDataSource>
{
UIPickerView *myPickerView;
NSMutableArray *arrayYear;
NSMutableArray *arrayMonth;
NSMutableArray *arrayDay;
UILabel *lblDay;
UILabel *lblMonth;
UILabel *lblYear;
}
@end
有三个数组，分别包含日，月和年的数据，以及三个用于显示数据的UILabel。显然是一个挑选者。
现在来看看你的viewController.m部分。
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
// UIPickerView declaration by coding
myPickerView = [[UIPickerView alloc]initWithFrame:CGRectMake(0.0, 0.0, 320.0, 216.0)];
myPickerView.delegate = self;
myPickerView.showsSelectionIndicator = YES;
[self.view addSubview:myPickerView];
// add some day number to day array
arrayDay = [[NSMutableArray alloc]init];
for(int i=1;i<6;i++)
{
NSString *string = [NSString stringWithFormat:@"%d",i];
[arrayDay addObject:string];
}
// add some month string to month array
arrayMonth = [[NSMutableArray alloc]init];
[arrayMonth addObject:@"June"];
[arrayMonth addObject:@"July"];
[arrayMonth addObject:@"August"];
[arrayMonth addObject:@"September"];
[arrayMonth addObject:@"October"];
// add some year number to year array
arrayYear = [[NSMutableArray alloc]init];
for(int i=2006;i<2011;i++)
{
NSString *string = [NSString stringWithFormat:@"%d",i];
[arrayYear addObject:string];
}
//set initially text to day label
lblDay = [[UILabel alloc]initWithFrame:CGRectMake(10.0, 250.0, 90.0, 50.0)];
[lblDay setText:[arrayDay objectAtIndex:0]];
[self.view addSubview:lblDay];
//set initially text to month label
lblMonth = [[UILabel alloc]initWithFrame:CGRectMake(110.0, 250.0, 90.0, 50.0)];
[lblMonth setText:[arrayMonth objectAtIndex:0]];
[self.view addSubview:lblMonth];
//set initially text to year label
lblYear = [[UILabel alloc]initWithFrame:CGRectMake(210.0, 250.0, 90.0, 50.0)];
[lblYear setText:[arrayYear objectAtIndex:0]];
[self.view addSubview:lblYear];
//set initially selection to each component of UIPickerView
[myPickerView selectRow:1 inComponent:0 animated:NO];
[myPickerView selectRow:1 inComponent:1 animated:NO];
[myPickerView selectRow:1 inComponent:2 animated:NO];
}
//here you are returning the number of component, which are 3 in this case
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView;
{
return 3;
}
//this is your didSelectRow method and here you are assigning a new text to
//label accordingly to if condition
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
if(component == 0)
{
lblDay.text = [arrayDay objectAtIndex:row];
}
if(component == 1)
{
lblMonth.text = [arrayMonth objectAtIndex:row];
}
if(component == 2)
{
lblYear.text = [arrayYear objectAtIndex:row];
}
}
//this is your numberOf row in component in this case each component have 5
//rows thats why i wrote only return 5; here you can put if condition here for
//returning different rows for each component
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component;
{
return 5;
}
// and this is showing title on rows
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component;
{
if (component == 0)
return [arrayDay objectAtIndex:row];
else if (component == 1)
return [arrayMonth objectAtIndex:row];
else if (component == 2)
return [arrayYear objectAtIndex:row];
else
return 0;
}
我希望本教程能为您提供帮助。谢谢！
答案 2 :(得分：0)
在你的程序中，你将字符串附加到一个问题的整数。
这段代码就是这个问题。因为year是一个整数。
labelDate1.text = [year stringByAppendingFormat:@" : %d : %d", month, day];
请查看此代码。
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
int year = [picker selectedRowInComponent:0];
int month = [picker selectedRowInComponent:1];
int day = [picker selectedRowInComponent:2];
NSString *date = @"";
if(viewPicker.tag == 1)
labelDate1.text = [date stringByAppendingFormat:@" %d : %d : %d",year, month, day];
else
labelDate2.text = [date stringByAppendingFormat:@"%d : %d : %d", year, month, day];
}