Question

我正在使用微调器和arrayAdapter来填充微调器中的项目。我想让微调器多选，但我只选择一行。我在谷歌搜索，解决方案可用Java，但我不知道如何在Xamarin中实现它。

我的代码如下，

adapterList= new ArrayAdapter<string>(this, Android.Resource.Layout.SimpleListItemMultipleChoice);

spnMultiTest.Adapter = adapterList;

Answer 1

我想让微调器多选，但我只选择一行。我在谷歌搜索，解决方案有Java，但我不知道如何在Xamarin中实现它。

基本上我只是将代码从Android Spinner with multiple choice 翻译成Xamarin代码。我测试了它，它工作正常：

MultiSpinner.cs：

public interface MultiSpinnerListener
{
    void onItemsSelected(bool[] selected);
}
public class MultiSpinner : Spinner, IDialogInterfaceOnMultiChoiceClickListener, IDialogInterfaceOnCancelListener
{
    Context _context;

    private List<String> items;
    private bool[] selected;
    private String defaultText;
    private MultiSpinnerListener listener;

    public MultiSpinner(Context context) : base(context)
    {
        _context = context;
    }

    public MultiSpinner(Context context, IAttributeSet arg1) : base(context, arg1)
    {
        _context = context;
   }

    public MultiSpinner(Context context, IAttributeSet arg1, int arg2) : base(context, arg1, arg2)
    {
        _context = context;
    }


    public  void OnClick(IDialogInterface dialog, int which, bool isChecked)
    {
        if (isChecked)
            selected[which] = true;
        else
            selected[which] = false;
    }

    public override void OnClick(IDialogInterface dialog, int which)
    {
        dialog.Cancel();
    }


    public override bool PerformClick()
    {
        AlertDialog.Builder builder = new AlertDialog.Builder(_context);
        builder.SetMultiChoiceItems(
                items.ToArray(), selected, this);

        builder.SetPositiveButton("OK",this);
        builder.SetOnCancelListener(this);
        builder.Show();
        return true;
    }


    public void SetItems(List<String> items, String allText,
        MultiSpinnerListener listener)
    {

        this.items = items;
        this.defaultText = allText;
        this.listener = listener;

        // all selected by default
        selected = new bool[items.Count];
        for (int i = 0; i < selected.Length; i++)
            selected[i] = true;
        ArrayAdapter<string> adapter = new ArrayAdapter<string>(_context,Resource.Layout.simple_spinner_item,Resource.Id.tv_item,new string[] { allText });
        // all text on the spinner
        //ArrayAdapter<String> adapter = new ArrayAdapter<String>(_context,Resource.Layout.simple_spinner_item, new String[] { allText });
        Adapter = adapter;
    }

    public void OnCancel(IDialogInterface dialog)
    {
        Java.Lang.StringBuffer spinnerBuffer = new Java.Lang.StringBuffer();
        bool someUnselected = false;
        for (int i = 0; i < items.Count; i++)
        {
            if (selected[i] == true)
            {
                spinnerBuffer.Append(items[i]);
                spinnerBuffer.Append(", ");
            }
            else
            {
                someUnselected = true;
            }
        }
        String spinnerText;
        if (someUnselected)
        {
            spinnerText = spinnerBuffer.ToString();
            if (spinnerText.Length > 2)
                spinnerText = spinnerText.Substring(0, spinnerText.Length - 2);
        }
        else
        {
            spinnerText = defaultText;
        }
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(_context,Resource.Layout.simple_spinner_item,Resource.Id.tv_item,new string[] { spinnerText });
        Adapter = adapter;
        if (listener != null)
        {
           listener.onItemsSelected(selected);
        }

    }


}

simple_spinner_item.xml：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
  <TextView
    android:id="@+id/tv_item"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    />
</LinearLayout>

<强>更新

以下是使用此MultiSpinner的代码：

Main.axml：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
  <MultiSpinner.MultiSpinner
    android:id="@+id/mSpinner"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    />
</LinearLayout>

MainActivity.cs：

public class MainActivity : Activity
{
    MultiSpinner mSpinner;
    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);

        // Set our view from the "main" layout resource
        SetContentView(Resource.Layout.Main);
        mSpinner = FindViewById<MultiSpinner>(Resource.Id.mSpinner);
        List<string> items = new List<string> {
            "Android",
            "iOS",
            "UWP"
        };

        mSpinner.SetItems(items, "AllText", null);
    }
}

Multi Select Spinner Xamarin Android

1 个答案: