Trouble with UIPickerView Outlets in iOS5?

Question

I don't understand which outlets should be connected! In outlets i have:

dataSource delegate

But where should i connect them? And how can i then use them?

???

Answer 1

In Xcode, connect the datasource & delegate outlets to the UIViewController that contains the UIPickerView. The datasource methods are declared in the UIViewController implementation. Let's say your picker will display: "English" and "French":

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView 
{
    return 2;
}

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
    NSArray *pickerContent = [NSArray arrayWithObjects:@"English", @"French", nil];
    return [pickerContent objectAtIndex:row];
}

The delegate methods are also declared in the UIViewController implementation:

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
    NSArray *titles = [NSArray arrayWithObjects:@"English", @"French", nil];
    NSString *userSelectionFromPicker = [titles objectAtIndex:row];
}

Some examples of how userSelectionFromPicker can be used to perform an action in the app:

1. A View Controller method: [localMethod doSomethingWith:userSelectionFromPicker]
2. NB: userSelectionFromPicker is made a property of the View Controller (as opposed to a local variable) and accessed by the View Controller's delegate - often when the View Controller is dismissed
3. A notification is invoked when userSelectionFromPicker changes