My label can't get value from pickerview - iphone

Question

My numberOfComponentsInPickerView :
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
return 3;
}
My 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;
}
My titleForRow like this:
- (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;
}
my didSelectRow like this
after edited like Paras Joshi's said :
- (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];
}
it still gives me error " bad receiver type 'int' " and i still don't get it how to fix it. how my label get data from titleForRow?
both input for year month and day all are number only (from 0 to 99) so that i wrote -> return [NSString stringWithFormat:#"%d", row];
i dont put data for my pickerview at - (void)viewDidLoad because i want my labelDate1 or labelDate2 got data from pickerview. is there any possible my label get data from pickerview like i wrote above? or must i write my data at - (void)viewDidLoad ?
for any help, thank you for watching my question.

Answer 1

In your program you are appending string to an integer that is the issue.
This code makes the issue. Because year is an integer.
labelDate1.text = [year stringByAppendingFormat:#" : %d : %d", month, day];
Please check with this code.
- (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];
}

Answer 2

Did you set the UIPickerView's delegate?I mean, did your pickerView:didSelectRow:inComponent get called?

Answer 3

Hello #Piyo Piyo your
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
method is totally wrong, you are assigning NSInteger to NSString. Thats why you are getting en error. You should use NSArray for putting data in picker view row and picking data from here. Here i'm going to make a small sample code.
This is your viewController.h file...
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController<UIPickerViewDelegate, UIPickerViewDataSource>
{
UIPickerView *myPickerView;
NSMutableArray *arrayYear;
NSMutableArray *arrayMonth;
NSMutableArray *arrayDay;
UILabel *lblDay;
UILabel *lblMonth;
UILabel *lblYear;
}
#end
there are three array which will contain the data for day, month and year respectively and three UILabel for showing the data. and obviously one pickerview.
Now come to on your viewController.m part.
- (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;
}
I hope this tutorial will help you. Thank you!