使用 C# 组合框放置图像和字符串

Question

我需要为 Windows 窗体应用程序创建一个下拉菜单或组合框，其中包含一个小图像，然后是它旁边的一串文本。基本上，您可以将下拉列表中的每个“行”视为需要有一个图标，然后在图标右侧显示图标的名称。我在做这件事时遇到了困难——事实上，我完全没有成功。有谁知道完成这项任务的方法？任何帮助将不胜感激。谢谢！

Answer 1

我能够想出一些非常简单的代码来执行此操作（请参阅下面的代码片段）。该代码创建一个下拉控件，它在同一行中显示一个小彩色方块和该颜色的名称（参见照片）。感谢您在最初发布时提供的链接！希望这个控件将来可以帮助其他人。

图片：

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代码：

class ColorSelector : ComboBox
{
    public ColorSelector()
    {
        DrawMode = DrawMode.OwnerDrawFixed;
        DropDownStyle = ComboBoxStyle.DropDownList;
    }
 
    // Draws the items into the ColorSelector object
    protected override void OnDrawItem(DrawItemEventArgs e)
    {
        e.DrawBackground();
        e.DrawFocusRectangle();
 
        DropDownItem item = new DropDownItem(Items[e.Index].ToString());
        // Draw the colored 16 x 16 square
        e.Graphics.DrawImage(item.Image, e.Bounds.Left, e.Bounds.Top);
        // Draw the value (in this case, the color name)
        e.Graphics.DrawString(item.Value, e.Font, new
                SolidBrush(e.ForeColor), e.Bounds.Left + item.Image.Width, e.Bounds.Top + 2);
 
        base.OnDrawItem(e);
    }
}
 
public class DropDownItem
{
    public string Value
    {
        get { return value; }
        set { this.value = value; }
    }
    private string value;
 
    public Image Image
    {
        get { return img; }
        set { img = value; }
    }
    private Image img;
 
    public DropDownItem() : this("")
    {}
 
    public DropDownItem(string val)
    {
        value = val;
        this.img = new Bitmap(16, 16);
        Graphics g = Graphics.FromImage(img);
        Brush b = new SolidBrush(Color.FromName(val));
        g.DrawRectangle(Pens.White, 0, 0, img.Width, img.Height);
        g.FillRectangle(b, 1, 1, img.Width - 1, img.Height - 1);
    }
 
    public override string ToString()
    {
        return value;
    }
}

Answer 2

非常有帮助..
一些优化：

public sealed class ColorSelector : ComboBox
{
    public ColorSelector()
    {
        DrawMode = DrawMode.OwnerDrawFixed;
        DropDownStyle = ComboBoxStyle.DropDownList;
    }

    protected override void OnDrawItem(DrawItemEventArgs e)
    {
        e.DrawBackground();

        e.DrawFocusRectangle();

        if (e.Index >= 0 && e.Index < Items.Count)
        {
            DropDownItem item = (DropDownItem)Items[e.Index];

            e.Graphics.DrawImage(item.Image, e.Bounds.Left, e.Bounds.Top);

            e.Graphics.DrawString(item.Value, e.Font, new SolidBrush(e.ForeColor), e.Bounds.Left + item.Image.Width, e.Bounds.Top + 2);
        }

        base.OnDrawItem(e);
    }
}

和...

public sealed class DropDownItem
{
    public string Value { get; set; }

    public Image Image { get; set; }

    public DropDownItem()
        : this("")
    { }

    public DropDownItem(string val)
    {
        Value = val;
        Image = new Bitmap(16, 16);
        using (Graphics g = Graphics.FromImage(Image))
        {
            using (Brush b = new SolidBrush(Color.FromName(val)))
            {
                g.DrawRectangle(Pens.White, 0, 0, Image.Width, Image.Height);
                g.FillRectangle(b, 1, 1, Image.Width - 1, Image.Height - 1);
            }
        }
    }

    public override string ToString()
    {
        return Value;
    }
}

Answer 3

我解决了问题，我这样做了：

ComboBox MarcadorNS = new ComboBox();
MarcadorNS.Height = 30;
MarcadorNS.Width = 150;
MarcadorNS.SelectedValuePath = "Uid";
foreach (var temporalItem in GetPredefinedKinds())
{
    Image ImagenCombo = new Image();
    ImagenCombo.Source =
    new BitmapImage(new Uri(
       "Imagenes/Marcadores/" +
        temporalItem.Name.ToLower() + ".png", UriKind.Absolute));
    ImagenCombo.Height = 28;
    ImagenCombo.Width = 28;
    ImagenCombo.VerticalAlignment = VerticalAlignment.Top;
    ImagenCombo.HorizontalAlignment = HorizontalAlignment.Left;
    Label textoCombo = new Label();
    textoCombo.VerticalAlignment = VerticalAlignment.Top;
    textoCombo.HorizontalAlignment = HorizontalAlignment.Left;
    textoCombo.Content = BaseDatos.NombresDeMarcadores(temporalItem.ToString());
    Grid GridCombo = new Grid();
    GridCombo.Uid = ObtenerMarcador(temporalItem.ToString());
    StackPanel stackCombo = new StackPanel();
    stackCombo.Orientation = Orientation.Horizontal;
    stackCombo.Children.Add(ImagenCombo);
    stackCombo.Children.Add(textoCombo);
    GridCombo.Children.Add(stackCombo);
    MarcadorNS.Items.Add(GridCombo);
}

Answer 4

注意：此代码来自用户 que dal 的优化
如果您希望拥有一个不仅仅是颜色名称的字符串，请将 DropDownItem 更改为具有 2 个参数：字符串和颜色，然后只需更改画笔设置颜色的方式，如下所示：

    public DropDownItem(string val, Color color)
    {
        Value = val;
        Image = new Bitmap(16, 16);
        using (Graphics g = Graphics.FromImage(Image))
        {
            using (Brush b = new SolidBrush(color))
            {
                g.DrawRectangle(Pens.White, 0, 0, Image.Width, Image.Height);
                g.FillRectangle(b, 1, 1, Image.Width - 1, Image.Height - 1);
            }
        }
    }

然后您必须更改下拉列表项目如下：

    public DropDownItem()
        : this("", Color.Empty)
    {}

希望这有帮助:)

Answer 5

不确定图像，但这应该适用于字符串：

comboBox.Items.Add("String");