Very simple iPhone question. How to make UIPickerView with two columns? - iphone

Question

I have read other questions about creating a UIPickerView with two or more columns but cannot find the exact solution.
How is this done for the iPhone programmatically? How do you add static data? Thanks!

Answer 1

Make your controller (or whatever is controlling the behavior of the PickerView) support the UIPickerViewDelegate protocol. Then, implement:
- (int) numberOfColumnsInPickerView:(UIPickerView*)picker
to return the number of columns you want, and
- (int) pickerView:(UIPickerView*)picker numberOfRowsInColumn:(int)col
to return the number of rows for each column, and finally:
- (UIPickerTableCell*) pickerView:(UIPickerView*)picker tableCellForRow:(int)row inColumn:(int)col
to setup each cell.
See the reference for UIPickerView and UIPickerViewDelegate.

Answer 2

There is an excellent tutorial on this subject here.

Answer 3

Assuming you have a dictionary or a couple of arrays holding your static data. For simplicity I will go with a very simple array.
You have to modify your view controllers interface definition to tell the program that your view controller can provide data and delegation to a picker view.
#interface NVHomeViewController : UIViewController <UIPickerViewDelegate,UIPickerViewDataSource>
Than just implementing a couple of methods will make it work however documentation should be checked for other methods that are optional but provides more customization and control.
#interface NVHomeViewController : UIViewController <UIPickerViewDelegate,UIPickerViewDataSource>
NSArray *options;
- (void)viewDidLoad
{
[super viewDidLoad];
options = #[#"a",#"b",#"c",#"d"];
}
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{
return 1;
}
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{
return [options count];
}
-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{
return [options objectAtIndex:row];
}
-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{
NSLog(#"%# selected.",[options objectAtIndex:row]);
}