iphone - 如何根据另一个选择器的选择更改选择器行？

Question

我有两个选择器——国家和地区。我需要根据在国家选择器中选择的行来填充区域选择器。我有数组来填充两个选择器。我需要一些帮助来根据国家选择器的选择更改区域选择器的行。任何帮助将不胜感激。提前非常感谢。

Answer 1

好的，你有两个选择器，比如说 countryPicker 和 regionPicker。

在 UIPickerView 的委托(delegate)方法中添加一个条件

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{ 
    NSString *pickerTitle = @"";
    if (pickerView == countryPicker)
    {
        pickerTitle =  [countryFeeds objectAtindex:row];
        //assigns the country title if pickerView is countryPicker
    }
    else if (pickerView == regionPicker)
    {
        pickerTitle =  [regionFeeds objectAtindex:row];
        //assigns the region title if pickerView is regionPicker
    }

    return pickerTitle;
}
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
    if (pickerView == countryPicker)
    {
        //selects the region corresponding to the selected country.
        //totalRegions is a NSDictionary having country names as keys and array of their regions as values
        regionFeeds = [totalRegions objectForKey:[countryFeeds objectAtindex:row]];

        //Now reloading the regionPicker with new values.
        [regionPicker reloadAllComponents];
    }
    else if (pickerView == regionPicker)
    {
        // your code to select a region
    }
}

我希望这能解决你的问题:)
BR，哈里