How to Prepare ComboBoxEx Items and Images

  • Article

This topic demonstrates how to add items to a ComboBoxEx control.

To add an item to a ComboBoxEx control, first define a COMBOBOXEXITEM structure. Then, set the mask member of the structure to indicate which members you want the control to use. Finally, set the specified members of the structure to the desired values and send the CBEM_INSERTITEM message to add the item to the control.

The following application-defined function adds 15 items to an existing ComboBoxEx control.

What you need to know

Technologies

Prerequisites

  • C/C++
  • Windows User Interface Programming

Instructions

Step 1:

To add an item to a ComboBoxEx control, first define a COMBOBOXEXITEM structure.

COMBOBOXEXITEM cbei;
int iCnt;


typedef struct {
    int iImage;
    int iSelectedImage;
    int iIndent;
    LPTSTR pszText;
} ITEMINFO, *PITEMINFO;

ITEMINFO IInf[ ] = {
    { 0, 3,  0, L"first"}, 
    { 1, 4,  1, L"second"},
    { 2, 5,  2, L"third"},
    { 0, 3,  0, L"fourth"},
    { 1, 4,  1, L"fifth"},
    { 2, 5,  2, L"sixth"},
    { 0, 3,  0, L"seventh"},
    { 1, 4,  1, L"eighth"},
    { 2, 5,  2, L"ninth"},
    { 0, 3,  0, L"tenth"},
    { 1, 4,  1, L"eleventh"},
    { 2, 5,  2, L"twelfth"},
    { 0, 3,  0, L"thirteenth"},
    { 1, 4,  1, L"fourteenth"},
    { 2, 5,  2, L"fifteenth"}
};

Step 2:

Set the mask member of the structure to indicate which members you want the control to use. Note that the mask member of the COMBOBOXEXITEM structure includes flag values that tell the control to display images for each item.

// Set the mask common to all items.
cbei.mask = CBEIF_TEXT | CBEIF_INDENT |
            CBEIF_IMAGE| CBEIF_SELECTEDIMAGE;

Step 3:

Set the specified members of the structure to the values you want, and then send the CBEM_INSERTITEM message to add the item to the control.

for(iCnt=0;iCnt<MAX_ITEMS;iCnt++){
    // Initialize the COMBOBOXEXITEM struct.
    cbei.iItem          = iCnt;
    cbei.pszText        = IInf[iCnt].pszText;
    cbei.cchTextMax     = sizeof(IInf[iCnt].pszText);
    cbei.iImage         = IInf[iCnt].iImage;
    cbei.iSelectedImage = IInf[iCnt].iSelectedImage;
    cbei.iIndent        = IInf[iCnt].iIndent;

    
    // Tell the ComboBoxEx to add the item. Return FALSE if 
    // this fails.
    if(SendMessage(hwndCB,CBEM_INSERTITEM,0,(LPARAM)&cbei) == -1)
        return FALSE;

Step 4:

Assign the existing image list to the ComboBoxEx control and set the size of control.

// Assign the existing image list to the ComboBoxEx control 
// and return TRUE. 
// g_himl is the handle to the existing image list
SendMessage(hwndCB,CBEM_SETIMAGELIST,0,(LPARAM)g_himl);

// Set size of control to make sure it's displayed correctly now
// that the image list is set.
SetWindowPos(hwndCB,NULL,20,20,250,120,SWP_NOACTIVATE);

return TRUE;

Complete example

// AddItems - Uses the CBEM_INSERTITEM message to add items to an
// existing ComboBoxEx control.

BOOL WINAPI AddItems(HWND hwndCB)
{
    
    //  Declare and init locals.
    COMBOBOXEXITEM cbei;
    int iCnt;
    

    typedef struct {
        int iImage;
        int iSelectedImage;
        int iIndent;
        LPTSTR pszText;
    } ITEMINFO, *PITEMINFO;

    ITEMINFO IInf[ ] = {
        { 0, 3,  0, L"first"}, 
        { 1, 4,  1, L"second"},
        { 2, 5,  2, L"third"},
        { 0, 3,  0, L"fourth"},
        { 1, 4,  1, L"fifth"},
        { 2, 5,  2, L"sixth"},
        { 0, 3,  0, L"seventh"},
        { 1, 4,  1, L"eighth"},
        { 2, 5,  2, L"ninth"},
        { 0, 3,  0, L"tenth"},
        { 1, 4,  1, L"eleventh"},
        { 2, 5,  2, L"twelfth"},
        { 0, 3,  0, L"thirteenth"},
        { 1, 4,  1, L"fourteenth"},
        { 2, 5,  2, L"fifteenth"}
    };

    // Set the mask common to all items.
    cbei.mask = CBEIF_TEXT | CBEIF_INDENT |
                CBEIF_IMAGE| CBEIF_SELECTEDIMAGE;

    for(iCnt=0;iCnt<MAX_ITEMS;iCnt++){
        // Initialize the COMBOBOXEXITEM struct.
        cbei.iItem          = iCnt;
        cbei.pszText        = IInf[iCnt].pszText;
        cbei.cchTextMax     = sizeof(IInf[iCnt].pszText);
        cbei.iImage         = IInf[iCnt].iImage;
        cbei.iSelectedImage = IInf[iCnt].iSelectedImage;
        cbei.iIndent        = IInf[iCnt].iIndent;
    
        
        // Tell the ComboBoxEx to add the item. Return FALSE if 
        // this fails.
        if(SendMessage(hwndCB,CBEM_INSERTITEM,0,(LPARAM)&cbei) == -1)
            return FALSE;
    }
    // Assign the existing image list to the ComboBoxEx control 
    // and return TRUE. 
    // g_himl is the handle to the existing image list
    SendMessage(hwndCB,CBEM_SETIMAGELIST,0,(LPARAM)g_himl);

    // Set size of control to make sure it's displayed correctly now
    // that the image list is set.
    SetWindowPos(hwndCB,NULL,20,20,250,120,SWP_NOACTIVATE);

    return TRUE; 
}

About ComboBoxEx Controls

ComboBoxEx Control Reference

Using ComboBoxEx Controls

ComboBoxEx