Question

我正在按照此答案https://stackoverflow.com/a/13385209/848968使用以下代码在组合框中显示代表颜色的图像我已经将自定义控件添加到了表单中，但是我不知道如何向其中添加带有图像的项目。敬请注意。

  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);
        }
    }

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 1

根据您的要求，我修改了OnDrawItem方法并更改了comboBox的宽度和高度以清除可见的图像

请在下面找到代码

    protected override void OnDrawItem(DrawItemEventArgs e)
    {
        if (e.Index >= 0  )
        {
            e.DrawBackground();
            e.DrawFocusRectangle();

            string imageFilePath = @Items[e.Index].ToString();;
            int width = 40;
            int height = 20;

            Image img = Image.FromFile(imageFilePath);
            e.Graphics.DrawImage(img, 0, e.Bounds.Top + 2, width, height);
            e.Graphics.DrawString(imageFilePath, e.Font, new
                    SolidBrush(e.ForeColor), e.Bounds.Left + width, e.Bounds.Top + 2);
            base.OnDrawItem(e);
        }

    }

}

输出：

在组合框中显示图像

1 个答案: