Spinner.SetSelection（0）重置Xamarin.Android中的第二个Spinner

Question

My issue is that I have 2 Spinners in Xamarin.Android that needs to reset each other depending on which one is selected. Say I select something from Spinner1, then Spinner2 has to be reset and vice-versa, with Spinner.SetSelection(0) so that they defaults back to the 0 item.

Here's the code which in theory should work, but doesn't. What happens is when either one of them has an ItemSelected, both of the Spinners gets their SetSelected function called and both are reset, even tho both Spinners have their own Adapter, with their own function/event to call.

What could be the issue?

Code:

public Spinner spinner1;
public Spinner spinner2;

public void Init() {
    List<string> items = new List<string>();

    //Populate dta into Items for Adapter
    foreach(Data d in datas)
    {
        items.Add(d.ToString());
    }

    var adapter1 = new ArrayAdapter<string>(this, Resource.Layout.spinner_item, items);
    adapter1.SetDropDownViewResource(Resource.Layout.spinner_item);
    spinner1.Adapter = adapter;
    spinner1.ItemSelected += spinner1_ItemSelected;

    var adapter2 = new ArrayAdapter<string>(this, Resource.Layout.spinner_item, items);
    adapter2.SetDropDownViewResource(Resource.Layout.spinner_item);
    spinner2.Adapter = adapter;
    spinner2.ItemSelected += spinner2_ItemSelected;
}


public void spinner1_ItemSelected(object sender, AdapterView.ItemSelectedEventArgs e) {
    Spinner spinner = (Spinner)sender;
    string value = spinner.GetItemAtPosition(e.Position).ToString();
    //Use value ...

    //Reset spinner2
    spinner2.SetSelection(0);
}

public void spinner2_ItemSelected(object sender, AdapterView.ItemSelectedEventArgs e) {
    Spinner spinner = (Spinner)sender;
    string value = spinner.GetItemAtPosition(e.Position).ToString();
    //Use value ...

    //Reset spinner1
    spinner1.SetSelection(0);
}

Answer 1

Your code is correct as your issue says that, when you change the first spinner second spinner resets also you have written the reset code for spinner1 to reset it in the spinner two itemSelected. Whenever you change the spinner 1 content spinner two gets resetted to 0 th position. When spinner2 resetted to 0 th position at that time spinner2_ItemSelected will execute, so only both get reset.

Be clear with your need and change accordingly

public void spinner1_ItemSelected(object sender, AdapterView.ItemSelectedEventArgs e) {
    Spinner spinner = (Spinner)sender;
    string value = spinner.GetItemAtPosition(e.Position).ToString();
    //Use value ...

    //Reset spinner2
    spinner2.SetSelection(0);
}

public void spinner2_ItemSelected(object sender, AdapterView.ItemSelectedEventArgs e) {
    Spinner spinner = (Spinner)sender;
    string value = spinner.GetItemAtPosition(e.Position).ToString();
    //Use value ...

    //Reset spinner1
    //spinner1.SetSelection(0);
}

Answer 2

I found a solution for a my issue. It's probably a hack solution, but since none could figure out how to solve this, this has to do for now:

public Spinner spinner1;
public Spinner spinner2;

public enum Spinners {
    Spinner1, Spinner2, None
}

public Types SelectedSpinner;
public bool IsChangingSpinner;

public void Init() {
    SelectedSpinner = Spinners.None;
    IsChangingSpinner = false;

    List<string> items = new List<string>();

    //Populate dta into Items for Adapter
    foreach(Data d in datas)
    {
        items.Add(d.ToString());
    }

    var adapter1 = new ArrayAdapter<string>(this, Resource.Layout.spinner_item, items);
    adapter1.SetDropDownViewResource(Resource.Layout.spinner_item);
    spinner1.Adapter = adapter;
    spinner1.ItemSelected += spinner1_ItemSelected;

    var adapter2 = new ArrayAdapter<string>(this, Resource.Layout.spinner_item, items);
    adapter2.SetDropDownViewResource(Resource.Layout.spinner_item);
    spinner2.Adapter = adapter;
    spinner2.ItemSelected += spinner2_ItemSelected;
}


public void spinner1_ItemSelected(object sender, AdapterView.ItemSelectedEventArgs e) {
    if(IsChangingSpinner == false) {
        Spinner spinner = (Spinner)sender;
        string value = spinner.GetItemAtPosition(e.Position).ToString();
        //Use value ...

        //Reset spinner2
        IsChangingSpinner = true;
        spinner2.SetSelection(0);

        if(SelectedSpinner == Spinners.Spinner1) {
            IsChangingSpinner = false;
        }

        SelectedSpinner = Spinners.Spinner1;

    } else {
        IsChangingSpinner = false;
    }
}

public void spinner2_ItemSelected(object sender, AdapterView.ItemSelectedEventArgs e) {
    if(IsChangingSpinner == false) {
        Spinner spinner = (Spinner)sender;
        string value = spinner.GetItemAtPosition(e.Position).ToString();
        //Use value ...

        //Reset spinner1
        IsChangingSpinner = true;
        spinner1.SetSelection(0);

        if(SelectedSpinner == Spinners.Spinner2) {
            IsChangingSpinner = false;
        }

        SelectedSpinner = Spinners.Spinner2;
    } else {
        IsChangingSpinner = false;
    }

}