如何更改 ComboBox 下拉按钮颜色 [英] How to change the ComboBox dropdown button color

问题描述

如何更改滑动按钮的颜色?不是边框颜色，也不是幻灯片项目颜色.

我已经更改了幻灯片项目的颜色

有什么办法可以改变颜色吗?

解决方案

Flat ComboBox - 更改边框颜色和下拉按钮颜色

您需要自己处理 WM_PAINT 并绘制边框和下拉矩形.这是内部

代码如下:

使用系统；使用 System.ComponentModel;使用 System.Drawing；使用 System.Runtime.InteropServices；使用 System.Windows.Forms;公共类 FlatComboBox : ComboBox{私有颜色 borderColor = Color.Gray;[默认值(typeof(颜色)，灰色")]公共颜色边框颜色{得到 { 返回边框颜色；}放{如果(边框颜色！= 值){边框颜色 = 值；无效()；}}}私有颜色 buttonColor = Color.LightGray;[默认值(typeof(颜色)，LightGray")]公共颜色按钮颜色{得到 { 返回按钮颜色；}放{如果(按钮颜色！= 值){按钮颜色 = 值；无效()；}}}protected override void WndProc(ref Message m){if (m.Msg == WM_PAINT && DropDownStyle != ComboBoxStyle.Simple){var clientRect = ClientRectangle;var dropDownButtonWidth = SystemInformation.Horizo​​ntalScrollBarArrowWidth;var externalBorder = new Rectangle(clientRect.Location,新尺寸(clientRect.Width - 1, clientRect.Height - 1));var innerBorder = new Rectangle(outerBorder.X + 1, outerBorder.Y + 1,externalBorder.Width - dropDownButtonWidth - 2，outerBorder.Height - 2);varinnerInnerBorder = new Rectangle(innerBorder.X + 1, innerBorder.Y + 1,innerBorder.Width - 2，innerBorder.Height - 2);var dropDownRect = new Rectangle(innerBorder.Right + 1,innerBorder.Y,dropDownButtonWidth,innerBorder.Height + 1);if (RightToLeft == RightToLeft.Yes){innerBorder.X = clientRect.Width - innerBorder.Right;innerInnerBorder.X = clientRect.Width - innerInnerBorder.Right;dropDownRect.X = clientRect.Width - dropDownRect.Right;dropDownRect.Width += 1;}var innerBorderColor = 启用?背景色:SystemColors.Control;无功outerBorderColor = 启用?BorderColor : SystemColors.ControlDark;var buttonColor = 启用?ButtonColor : SystemColors.Control;var middle = new Point(dropDownRect.Left + dropDownRect.Width/2,dropDownRect.Top + dropDownRect.Height/2);var 箭头 = 新点 []{new Point(middle.X - 3, middle.Y - 2),new Point(middle.X + 4, middle.Y - 2),新点(中间.X，中间.Y + 2)};var ps = new PAINTSTRUCT();bool shoulEndPaint = false;IntPtr dc;if (m.WParam == IntPtr.Zero){dc = 开始绘制(句柄，参考 ps)；m.WParam = dc;shoulEndPaint = 真；}别的{dc = m.WParam;}var rgn = CreateRectRgn(innerInnerBorder.Left,innerInnerBorder.Top,innerInnerBorder.Right，innerInnerBorder.Bottom);SelectClipRgn(dc, rgn);DefWndProc(ref m);删除对象(rgn)；rgn = CreateRectRgn(clientRect.Left, clientRect.Top,clientRect.Right, clientRect.Bottom);SelectClipRgn(dc, rgn);使用 (var g = Graphics.FromHdc(dc)){使用 (var b = new SolidBrush(buttonColor)){g.FillRectangle(b, dropDownRect);}使用 (var b = new SolidBrush(outerBorderColor)){g.FillPolygon(b, 箭头);}使用 (var p = new Pen(innerBorderColor)){g.DrawRectangle(p,innerBorder);g.DrawRectangle(p,innerInnerBorder);}使用 (var p = new Pen(outerBorderColor)){g.DrawRectangle(p,outerBorder);}}如果(应该结束油漆)EndPaint(句柄，参考 ps)；删除对象(rgn)；}别的base.WndProc(ref m);}私有常量 int WM_PAINT = 0xF;[结构布局(LayoutKind.Sequential)]公共结构 RECT{公共 int L、T、R、B；}[结构布局(LayoutKind.Sequential)]公共结构 PAINTSTRUCT{公共 IntPtr hdc;公共布尔删除；公共 int rcPaint_left;公共 int rcPaint_top;公共 int rcPaint_right;公共 int rcPaint_bottom;公共布尔 fRestore；public bool fIncUpdate;public int reserved1;public int reserved2;public int reserved3;public int reserved4;public int reserved5;public int reserved6;public int reserved7;public int reserved8;}[DllImport(user32.dll")]private static extern IntPtr BeginPaint(IntPtr hWnd,[输入，输出] ref PAINTSTRUCT lpPaint);[DllImport(user32.dll")]private static extern bool EndPaint(IntPtr hWnd, ref PAINTSTRUCT lpPaint);[DllImport(gdi32.dll")]public static extern int SelectClipRgn(IntPtr hDC, IntPtr hRgn);[DllImport(user32.dll")]public static extern int GetUpdateRgn(IntPtr hwnd, IntPtr hrgn, bool fErase);公共枚举 RegionFlags{错误 = 0,NULLREGION = 1,简单区域 = 2,复杂区域 = 3,}[DllImport(gdi32.dll")]内部静态 extern bool DeleteObject(IntPtr hObject);[DllImport(gdi32.dll")]私有静态外部 IntPtr CreateRectRgn(int x1, int y1, int x2, int y2);}

How could I change the slide button color? not border color and not slide item colors.

I already change the slide item colors

Is there any way to change the color?

解决方案

Flat ComboBox - Change border color and Dropdown button color

You need to handle WM_PAINT yourself and draw the border and the dropdown rectangle. This is the way that internal ComboBox.FlatComboAdapter class of .Net Framework works.

In this post, I've created a FlatComboBox, which draws the border and the dropdown in a flat style, having the following additional properties:

• BorderColor: used for border and for the dropdown arrow
• ButtonColor: used for dropdown area color.

Here is the code:

using System;
using System.ComponentModel;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;
public class FlatComboBox : ComboBox
{
    private Color borderColor = Color.Gray;
    [DefaultValue(typeof(Color), "Gray")]
    public Color BorderColor
    {
        get { return borderColor; }
        set
        {
            if (borderColor != value)
            {
                borderColor = value;
                Invalidate();
            }
        }
    }
    private Color buttonColor = Color.LightGray;
    [DefaultValue(typeof(Color), "LightGray")]
    public Color ButtonColor
    {
        get { return buttonColor; }
        set
        {
            if (buttonColor != value)
            {
                buttonColor = value;
                Invalidate();
            }
        }
    }
    protected override void WndProc(ref Message m)
    {
        if (m.Msg == WM_PAINT && DropDownStyle != ComboBoxStyle.Simple)
        {
            var clientRect = ClientRectangle;
            var dropDownButtonWidth = SystemInformation.HorizontalScrollBarArrowWidth;
            var outerBorder = new Rectangle(clientRect.Location,
                new Size(clientRect.Width - 1, clientRect.Height - 1));
            var innerBorder = new Rectangle(outerBorder.X + 1, outerBorder.Y + 1,
                outerBorder.Width - dropDownButtonWidth - 2, outerBorder.Height - 2);
            var innerInnerBorder = new Rectangle(innerBorder.X + 1, innerBorder.Y + 1,
                innerBorder.Width - 2, innerBorder.Height - 2);
            var dropDownRect = new Rectangle(innerBorder.Right + 1, innerBorder.Y,
                dropDownButtonWidth, innerBorder.Height + 1);
            if (RightToLeft == RightToLeft.Yes)
            {
                innerBorder.X = clientRect.Width - innerBorder.Right;
                innerInnerBorder.X = clientRect.Width - innerInnerBorder.Right;
                dropDownRect.X = clientRect.Width - dropDownRect.Right;
                dropDownRect.Width += 1;
            }
            var innerBorderColor = Enabled ? BackColor : SystemColors.Control;
            var outerBorderColor = Enabled ? BorderColor : SystemColors.ControlDark;
            var buttonColor = Enabled ? ButtonColor : SystemColors.Control;
            var middle = new Point(dropDownRect.Left + dropDownRect.Width / 2,
                dropDownRect.Top + dropDownRect.Height / 2);
            var arrow = new Point[]
            {
                new Point(middle.X - 3, middle.Y - 2),
                new Point(middle.X + 4, middle.Y - 2),
                new Point(middle.X, middle.Y + 2)
            };
            var ps = new PAINTSTRUCT();
            bool shoulEndPaint = false;
            IntPtr dc;
            if (m.WParam == IntPtr.Zero)
            {
                dc = BeginPaint(Handle, ref ps);
                m.WParam = dc;
                shoulEndPaint = true;
            }
            else
            {
                dc = m.WParam;
            }
            var rgn = CreateRectRgn(innerInnerBorder.Left, innerInnerBorder.Top, 
                innerInnerBorder.Right, innerInnerBorder.Bottom);
            SelectClipRgn(dc, rgn);
            DefWndProc(ref m);
            DeleteObject(rgn);
            rgn = CreateRectRgn(clientRect.Left, clientRect.Top, 
                clientRect.Right, clientRect.Bottom);
            SelectClipRgn(dc, rgn);
            using (var g = Graphics.FromHdc(dc))
            {
                using (var b = new SolidBrush(buttonColor))
                {
                    g.FillRectangle(b, dropDownRect);
                }
                using (var b = new SolidBrush(outerBorderColor))
                {
                    g.FillPolygon(b, arrow);
                }
                using (var p = new Pen(innerBorderColor))
                {
                    g.DrawRectangle(p, innerBorder);
                    g.DrawRectangle(p, innerInnerBorder);
                }
                                    using (var p = new Pen(outerBorderColor))
                {
                    g.DrawRectangle(p, outerBorder);
                }
            }
            if (shoulEndPaint)
                EndPaint(Handle, ref ps);
            DeleteObject(rgn);
        }
        else
            base.WndProc(ref m);
    }

    private const int WM_PAINT = 0xF;
    [StructLayout(LayoutKind.Sequential)]
    public struct RECT
    {
        public int L, T, R, B;
    }
    [StructLayout(LayoutKind.Sequential)]
    public struct PAINTSTRUCT
    {
        public IntPtr hdc;
        public bool fErase;
        public int rcPaint_left;
        public int rcPaint_top;
        public int rcPaint_right;
        public int rcPaint_bottom;
        public bool fRestore;
        public bool fIncUpdate;
        public int reserved1;
        public int reserved2;
        public int reserved3;
        public int reserved4;
        public int reserved5;
        public int reserved6;
        public int reserved7;
        public int reserved8;
    }
    [DllImport("user32.dll")]
    private static extern IntPtr BeginPaint(IntPtr hWnd,
        [In, Out] ref PAINTSTRUCT lpPaint);

    [DllImport("user32.dll")]
    private static extern bool EndPaint(IntPtr hWnd, ref PAINTSTRUCT lpPaint);

    [DllImport("gdi32.dll")]
    public static extern int SelectClipRgn(IntPtr hDC, IntPtr hRgn);

    [DllImport("user32.dll")]
    public static extern int GetUpdateRgn(IntPtr hwnd, IntPtr hrgn, bool fErase);
    public enum RegionFlags
    {
        ERROR = 0,
        NULLREGION = 1,
        SIMPLEREGION = 2,
        COMPLEXREGION = 3,
    }
    [DllImport("gdi32.dll")]
    internal static extern bool DeleteObject(IntPtr hObject);

    [DllImport("gdi32.dll")]
    private static extern IntPtr CreateRectRgn(int x1, int y1, int x2, int y2);
}

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