Question

当ComboBox的DropDownStyle为DropDownList且DrawMode为Normal时，它看起来不错，但是当我将DrawMode更改为OwnerDrawFixed时 - 它看起来非常糟糕（类似于带有箭头的TextBox下拉）。当DrawMode不正常时，有什么解决方案可以让它看起来很好吗？

看起来像这样： looks like that

我希望它看起来像那样： I want it to look like that

Answer 1

我在VB中找到了解决方案：how-to-make-a-custom-combobox-ownerdrawfixed-looks-3d-like-the-standard-combobo 添加了一些用于绘制文本和箭头的代码。它有效：）

class MyComboBox: ComboBox
{
    public MyComboBox()
    {
        this.SetStyle(ControlStyles.Opaque | ControlStyles.UserPaint, true);
        Items.Add("lol");
        Items.Add("lol2");  
    }

    protected override void OnPaint(PaintEventArgs e)
    {
        if (DroppedDown)
            ButtonRenderer.DrawButton(CreateGraphics(), new System.Drawing.Rectangle(ClientRectangle.X - 1, ClientRectangle.Y - 1, ClientRectangle.Width + 2, ClientRectangle.Height + 2), PushButtonState.Pressed);
        else
            ButtonRenderer.DrawButton(CreateGraphics(), new System.Drawing.Rectangle(ClientRectangle.X - 1, ClientRectangle.Y - 1, ClientRectangle.Width + 2, ClientRectangle.Height + 2), PushButtonState.Normal);
        if (SelectedIndex != -1)
        {
            Font font;
            if (SelectedItem.ToString().Equals("lol"))
                font = new Font(this.Font, FontStyle.Bold);
            else
                font = new Font(this.Font, FontStyle.Regular);
            e.Graphics.DrawString(Text, font, new SolidBrush(Color.Black), 3, 3);
        }
        if (DroppedDown)
            this.CreateGraphics().DrawImageUnscaled(new Bitmap("c:\\ArrowBlue.png"), ClientRectangle.Width - 13, ClientRectangle.Height - 12);
        else
            this.CreateGraphics().DrawImageUnscaled(new Bitmap("c:\\ArrowGray.png"), ClientRectangle.Width - 13, ClientRectangle.Height - 12);
        base.OnPaint(e);
    }

我不知道当鼠标进入和离开ComboBox时如何消除闪烁。当DoubleBuffering启用时，ComboBox为黑色。但对我来说工作正常。

Answer 2

当您将其更改为OwnerDrawFixed时，您应该自己处理绘图

        private void comboBox1_DrawItem(object sender, DrawItemEventArgs e)
                {
                    //Wrtie your code here
     e.Graphics.DrawString(comboBox1.Items[e.Index].ToString(), this.Font, Brushes.Black,e.Bounds);
e.DrawBackground();

                }

请参阅此链接ComboBoxRenderer Class

当DrawMode不正常时，我的ComboBox看起来很糟糕

2 个答案: