win32-改变Combox的编辑框和下拉列表的背景颜色和文本字体颜色

只需要调用WM_CTLCOLORLISTBOX和WM_CTLCOLOREDIT来分别处理编辑框和下拉列表。

Combox的创建：

int xpos = 100;            // Horizontal position of the window.
   int ypos = 100;            // Vertical position of the window.
   int nwidth = 200;          // Width of the window
   int nheight = 200;         // Height of the window
   HWND hwndParent = hWnd; // Handle to the parent window

   hWndComboBox = CreateWindow(WC_COMBOBOX, TEXT(""),
       CBS_DROPDOWNLIST | WS_CHILD |  WS_VISIBLE, // CBS_HASSTRINGS | WS_OVERLAPPED |
       xpos, ypos, nwidth, nheight, hwndParent, NULL, hInstance,
       NULL);

   // load the combobox with item list.  
   // Send a CB_ADDSTRING message to load each item

   TCHAR Planets[9][10] =
   {
       TEXT("Mercury"), TEXT("Venus"), TEXT("Terra"), TEXT("Mars"),
       TEXT("Jupiter"), TEXT("Saturn"), TEXT("Uranus"), TEXT("Neptune"),
       TEXT("Pluto??")
   };

   TCHAR A[16];
   int  k = 0;

   memset(&A, 0, sizeof(A));
   for (k = 0; k <= 8; k += 1)
   {
       wcscpy_s(A, sizeof(A) / sizeof(TCHAR), (TCHAR*)Planets[k]);

       // Add string to combobox.
       SendMessage(hWndComboBox, (UINT)CB_ADDSTRING, (WPARAM)0, (LPARAM)A);
   }

   // Send the CB_SETCURSEL message to display an initial item 
   //  in the selection field  
   SendMessage(hWndComboBox, CB_SETCURSEL, (WPARAM)2, (LPARAM)0);

这部分可以参考： How to Create a Simple Combo Box

接下来处理窗口处理过程：

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    
    case WM_CTLCOLORLISTBOX:
    {
        HDC dc = (HDC)wParam;
        SetBkMode(dc, OPAQUE);
        SetTextColor(dc, RGB(255, 255, 255));
        SetBkColor(dc, 0x383838); //0x383838
        HBRUSH comboBrush = CreateSolidBrush(0x383838); //global var
        return (LRESULT)comboBrush;      
    }
    case WM_CTLCOLOREDIT:
    {
        HDC dc = (HDC)wParam;
        SetBkMode(dc, OPAQUE);
        SetTextColor(dc, RGB(255, 255, 255));
        SetBkColor(dc, 0x383838); //0x383838
        HBRUSH comboBrush = CreateSolidBrush(0x383838); 
        return (LRESULT)comboBrush;
    }
    ...

最后的调试结果：

更新：

如果有多个组合框控件，我们需要分别改变它们的背景颜色和文本颜色。那么我们需要通过判断各个控件的窗口句柄来实现。

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {    
    case WM_CTLCOLORLISTBOX:
    {       
        COMBOBOXINFO info;
        info.cbSize = sizeof(info);
        SendMessage(hWndComboBox, CB_GETCOMBOBOXINFO, 0, (LPARAM)&info);
        COMBOBOXINFO info1;
        info1.cbSize = sizeof(info1);
        SendMessage(hWndComboBox1, CB_GETCOMBOBOXINFO, 0, (LPARAM)&info1);

        if ((HWND)lParam == info.hwndList)
        {
            HDC dc = (HDC)wParam;
            SetBkMode(dc, OPAQUE);
            SetTextColor(dc, RGB(255, 255, 0));
            SetBkColor(dc, 0x383838); //0x383838
            HBRUSH comboBrush = CreateSolidBrush(0x383838); //global var
            return (LRESULT)comboBrush;
        } 
        if ((HWND)lParam == info1.hwndList)
        {
            HDC dc = (HDC)wParam;
            SetBkMode(dc, OPAQUE);
            SetTextColor(dc, RGB(255, 0, 0));
            SetBkColor(dc, RGB(0, 0, 255)); 
            HBRUSH comboBrush = CreateSolidBrush(RGB(0, 0, 255)); 
            return (LRESULT)comboBrush;
        }
    }
    case WM_CTLCOLOREDIT:
    {
        HWND hWnd = (HWND)lParam;
        HDC dc = (HDC)wParam;
        if (hWnd == hWndComboBox)
        {
            SetBkMode(dc, OPAQUE);
            SetTextColor(dc, RGB(255, 0, 255));
            SetBkColor(dc, 0x383838); //0x383838
            HBRUSH comboBrush = CreateSolidBrush(0x383838); //global var
            return (LRESULT)comboBrush;
        }
        else if (hWnd == hWndComboBox1)
        {
            SetBkMode(dc, OPAQUE);
            SetTextColor(dc, RGB(255, 255, 0));
            SetBkColor(dc, RGB(0, 255, 0)); 
            HBRUSH comboBrush = CreateSolidBrush(RGB(0, 255, 0)); 
            return (LRESULT)comboBrush;
        }
    }
    ...