使用 SpannableString 设置 Spinner-Item Backgroundcolor

Question

我正在使用 SpannableStrings 为 Spinner 中的项目设置不同的背景颜色。

var spinnerList = new List<SpannableString>();
foreach(var mySpinnerItem in spinnerItems)
{
    var tmpSpannable = new SpannableString(mySpinnerItem.Text);
    tmpSpannable.SetSpan(new BackgroundColorSpan(mySpinnerItem.Color), 0, mySpinnerItem.Text.Length, 0);
    spinnerList.Add(tmpSpannable);
}

var spinnerAdapter = new ArrayAdapter<SpannableString>(Context, Android.Resource.Layout.SimpleSpinnerItem, spinnerList);
spinner.Adapter = spinnerAdapter;

结果如下所示：

我希望所有项目的宽度相同。

我找不到解决方案的两个可能结果：

将所有项目的宽度设置为最宽项目的宽度
将所有项的宽度设置为整个 Spinner 的宽度

我该如何解决这个问题，或者以编程方式为微调项设置不同背景颜色的替代方法是什么？

结果 1 应该是这样的：

请忽略第一个元素的字体颜色没有设置与背景形成对比

Answer 1

在这种情况下，你想列出所有国家或有大名单尝试：spinnerMode="dialog" 如下所示：

<Spinner
    android:id="@+id/spinnerId"
    android:layout_width="wrap_content"
    android:dropDownWidth="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="10dp"
    android:spinnerMode="dialog"/>

Answer 2

根据您上面的代码，它只是为您的文本视图添加背景颜色，而不是整个项目，您可以自定义适配器，然后将颜色设置为项目视图，这里是一个将 spinnerItems 传递给适配器：

[Activity(Label = "SpinnerActivity", MainLauncher = true)]
public class SpinnerActivity : Activity
{
    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);

        SetContentView(Resource.Layout.spinner);

        Spinner sp = FindViewById<Spinner>(Resource.Id.spinner);
        List<MySpinnerItem> spinnerItems = new List<MySpinnerItem>();
        spinnerItems.Add(new MySpinnerItem("Red-",Color.Red));
        spinnerItems.Add(new MySpinnerItem("Yellow--", Color.Yellow));
        spinnerItems.Add(new MySpinnerItem("Green-----", Color.Green));
        spinnerItems.Add(new MySpinnerItem("Blue---", Color.Blue));
        spinnerItems.Add(new MySpinnerItem("Black--------", Color.Black));
        var spinnerAdapter = new MyAdapter(this, Android.Resource.Layout.SimpleSpinnerItem, spinnerItems);
        sp.Adapter = spinnerAdapter;
    }
}

class MyAdapter : ArrayAdapter<MySpinnerItem>
{
    public Context context;
    public List<MySpinnerItem> list;
    public int textViewResourceId;
    public MyAdapter(Context context, int textViewResourceId, List<MySpinnerItem> objects) : base(context, textViewResourceId, objects)
    {
        this.context = context;
        list = objects;
        this.textViewResourceId = textViewResourceId;
    }

    public override View GetDropDownView(int position, View convertView, ViewGroup parent)
    {

        if (convertView == null)
        {
            LayoutInflater inflater = LayoutInflater.From(context);
            convertView = inflater.Inflate(textViewResourceId, parent, false);
        }
        TextView tv = (TextView)convertView.FindViewById(Android.Resource.Id.Text1);
        tv.Text = list[position].Text;
        convertView.SetBackgroundColor(list[position].Color);
        return convertView;
    }
    public override View GetView(int position, View convertView, ViewGroup parent)
    {

        if (convertView == null)
        {
            LayoutInflater inflater = LayoutInflater.From(context);
            convertView = inflater.Inflate(textViewResourceId, parent, false);
        }

        TextView tv = (TextView)convertView.FindViewById(Android.Resource.Id.Text1);
        tv.Text = list[position].Text;
        convertView.SetBackgroundColor(list[position].Color);
        return convertView;
    }
}

class MySpinnerItem
{
    public string Text;
    public Color Color;

    public MySpinnerItem(string text, Color color)
    {
        Text = text;
        Color = color;
    }
}

使用 SpannableString 设置 Spinner-Item Backgroundcolor

Set Spinner-Item Backgroundcolor with SpannableString

android

xamarin

spinner

background-color

spannablestring