Xamarin.Forms 中选择器上的 OnChangeListener

OnChangeListener on Picker in Xamarin.Forms

我有两个选择器,我从 Pickers 中得到了每个 SelectedItem,但每当我更改那里的值时,它们都不会触发我的方法,为什么?

下面是我的代码:

这是我声明每个选择器的选定索引的方式:

int selectedIndexYear = year_pk.SelectedIndex;
int selectedIndexTerm = term_pk.SelectedIndex;

这是每当我更改选择器时触发的逻辑,但它不起作用:

if (selectedIndexYear != -1 && selectedIndexTerm != -1)
{
    int term = Int32.Parse(term_pk.SelectedItem.ToString());
    //Below  is my method am Firing Each change of the Picker.
    OnResultsList(year_pk.SelectedItem.ToString(), term);
}

根据那个场景,我看到您想在选择器上选择的项目发生变化时触发一个事件。

我建议您使用 SelectedIndexChanged 事件如下:

year_pk.SelectedIndexChanged += delegate 
{
    int term = Int32.Parse(term_pk.SelectedItem.ToString());
    //Below  is my method am Firing Each change of the Picker.
    OnResultsList(year_pk.SelectedItem.ToString(), term);
}

term_pk.SelectedIndexChanged += delegate 
{
    int term = Int32.Parse(term_pk.SelectedItem.ToString());
    //Below  is my method am Firing Each change of the Picker.
    OnResultsList(year_pk.SelectedItem.ToString(), term);
}