Related
I consider using an owner draw menu in a Windows application that should have the same look as the standard menu. (Reason: the standard menu doesn't work well in some mixed DPI situations.)
Currently I have a problem providing the correct width during WM_MEASUREITEM.
This is a screenshot of the Edit menu of notepad where each item has a shortcut.
We can see that there is a constant gap between the item texts and shortcut texts as if they were columns. It seems as if the widths of the item texts and the widths of the shortcut texts are retrieved separately, as the longest item text "Time/Date" reserves a shortcut width suitable for Ctrl+A while it only needs one for F5.
I could not find any API functionality where I can give the width of the item text and the shortcut text separately, nor did I find any metric specifying the size of the gap.
So my question is: Is it possible to achieve the desired behavior within the usual WM_MEASUREITEM message and if yes, how? If not, is there any other means to get this right or is it just not possible at all?
This is how ReactOS does it:
To measure a menu item:
if ((p = wcschr( lpitem->Xlpstr, '\t' )) != NULL) {
RECT tmprc = rc;
LONG tmpheight;
int n = (int)( p - lpitem->Xlpstr);
/* Item contains a tab (only meaningful in popup menus) */
/* get text size before the tab */
txtheight = DrawTextW( hdc, lpitem->Xlpstr, n, &rc,
DT_SINGLELINE|DT_CALCRECT);
txtwidth = rc.right - rc.left;
p += 1; /* advance past the Tab */
/* get text size after the tab */
tmpheight = DrawTextW( hdc, p, -1, &tmprc,
DT_SINGLELINE|DT_CALCRECT);
lpitem->dxTab += txtwidth;
txtheight = max( txtheight, tmpheight);
txtwidth += MenuCharSize.cx + /* space for the tab */
tmprc.right - tmprc.left; /* space for the short cut */
}
Then to draw it:
Text = lpitem->Xlpstr;
if(Text)
{
for (i = 0; Text[i]; i++)
if (Text[i] == L'\t' || Text[i] == L'\b')
break;
}
if(lpitem->fState & MF_GRAYED)
DrawTextW( hdc, Text, i, &rect, uFormat);
/* paint the shortcut text */
if (!menuBar && L'\0' != Text[i]) /* There's a tab or flush-right char */
{
if (L'\t' == Text[i])
{
rect.left = lpitem->dxTab;
uFormat = DT_LEFT | DT_VCENTER | DT_SINGLELINE;
}
else
{
rect.right = lpitem->dxTab;
uFormat = DT_RIGHT | DT_VCENTER | DT_SINGLELINE;
}
DrawTextW( hdc, Text + i + 1, -1, &rect, uFormat );
}
So to insert a keyboard accelerator in a menu item, you simply separate it from the item text with the tab character. The measuring and drawing code then looks for this tab character and acts accordingly.
Note, however, that for the keyboard accelerator to be right-aligned in the menu like it is in your screenshot (which is achieved with DrawText with DT_RIGHT) the drawing code expects it to be separated from the item text with the '\b' character, not the tab character, and unless I'm missing something this is not accounted for in the measuring code, so you might want to compensate for that.
Replicating the standard menu with owner draw is a world of pain. You have to deal with Visual Styles on and off, mnemonics/Access keys, accessibility and all the undocumented metrics. It is better just to use the normal menu if you can.
Per-monitor DPI support seems to change in every Windows 10 release. 1607 added EnableNonClientDpiScaling which scales the menu and other non-client areas. 1703 added Per Monitor v2 and MSDN says this about PMv2:
Scaling of non-client area - All windows will automatically have their non-client area drawn in a DPI sensitive fashion. Calls to EnableNonClientDpiScaling are unnecessary.
Scaling of Win32 menus - All NTUSER menus created in Per Monitor v2 contexts will be scaling in a per-monitor fashion.
Notepad is PMv2 and its menu seems to work fine:
Windows 8.1 and < 10 Anniversary Update will require more work and I would suggest that you just don't declare yourself DPI aware on these systems and let Windows scale your window for you (with some blurriness) if the system has multiple monitors.
I want my console window to be modified. I got the handle. And this helps to change it. But how can I
remove close button
remove maximize button
remove icon
disable resizing
?
// C# syntax
StringBuilder buffer = new StringBuilder(260);
IntPtr window = FindWindow(null, buffer.ToString(0, GetConsoleTitle(buffer, buffer.Capacity)));
uint a = (uint)((WS_BORDER | WS_CAPTION) & (~WS_ICONIC));
SetWindowLongPtr(window, -16, new IntPtr(a)); // GWL_STYLE = -16
For some reason the window is broken after this call. I can't move it with the mouse anymore and all clicks go through it to other windows.
You removed all the window styles, and added back just WS_BORDER and WS_CAPTION. What you should do is:
Read the current window style with a call to GetWindowLongPtr.
Perform bitwise AND with the bitwise negation of the styles you want to remove.
Set the window style with a call to SetWindowLongPtr.
I have a win32 application that runs full screen when started. The application has some button which invoke pop up dialogs.
Is there a way to make the entire desktop (except the pop up) go transparent black unless the pop up is dismissed by the user? what I am talking of is similar to windows 7 UAC pop ups and the background it causes.
Is it possible to do similar stuff for a full screened window app?
It is possible do this…sort of. Perhaps I should say, you can simulate this effect. It won't actually be like the UAC dialog, as the user will still be able to interact with other running applications. There is no such concept as "system modal" available to applications. That's by design, of course. But you can certainly show a "light box" that dims out the rest of the desktop and forces focus on your app's dialog box.
The way I would do it is to create a giant layered window that sits on top of all other windows and covers the entire screen, fill it with black, and set the opacity as desired. Then, before you show a modal dialog (either by calling the MessageBox function or using the DialogBox function to show one of your own custom dialogs), display your light box window. Finally, after the user dismisses the modal dialog, you will destroy the light box window.
Here's some sample code. Error checking is omitted for brevity. So is other good style, like wrapping this mess up in one or more classes.
INT_PTR ShowLightBoxedDialog(HINSTANCE hInstance,
LPCTSTR pDlgTemplate,
HWND hwndParent,
DLGPROC pDlgProc,
BYTE opacityLevel)
{
const TCHAR szLightBoxClass[] = TEXT("LightBoxWndClass");
// Register the light box window class.
static bool lightBoxRegistered = false;
if (!lightBoxRegistered)
{
WNDCLASSEX wcex;
wcex.cbSize = sizeof(wcex);
wcex.style = CS_NOCLOSE | CS_SAVEBITS;
wcex.lpfnWndProc = LightBoxWndProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = hInstance;
wcex.hIcon = NULL;
wcex.hIconSm = NULL;
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground = NULL;
wcex.lpszMenuName = NULL;
wcex.lpszClassName = szLightBoxClass;
RegisterClassEx(&wcex);
lightBoxRegistered = true;
}
// Create and display the light box window.
HWND hwndLightBox = CreateWindowEx(WS_EX_NOACTIVATE | WS_EX_LAYERED,
szLightBoxClass,
NULL,
WS_POPUPWINDOW,
0, 0, 0, 0,
hwndParent,
NULL,
hInstance,
NULL);
SetLayeredWindowAttributes(hwndLightBox, 0, opacityLevel, LWA_ALPHA);
SetWindowPos(hwndLightBox,
HWND_TOP,
GetSystemMetrics(SM_XVIRTUALSCREEN),
GetSystemMetrics(SM_YVIRTUALSCREEN),
GetSystemMetrics(SM_CXVIRTUALSCREEN),
GetSystemMetrics(SM_CYVIRTUALSCREEN),
SWP_SHOWWINDOW);
// Display the modal dialog box (as you normally would).
// NOTE: The dialog box won't appear centered on the screen.
// For that, you will need to write centering code in response
// to the WM_INITDIALOG message in the dialog procedure.
INT_PTR result = DialogBox(hInstance, pDlgTemplate, hwndLightBox, pDlgProc);
//
// For demonstration purposes, I used the following code:
// INT_PTR result = MessageBox(hwndLightBox,
// TEXT("OH NOEZ!\n\nYour system is kaput! Abandon þe all hope."),
// NULL,
// MB_ABORTRETRYIGNORE | MB_ICONERROR);
// Destroy the light box window.
DestroyWindow(hwndLightBox);
// Return the result of the modal dialog box.
return result;
}
You'll notice that basically what I've done is created a wrapper around the DialogBox function, which you use whenever you want a dialog box with a "light box" effect. It takes all of the same parameters (the first 4), and then there's an additional one tacked on the end that allows you to specify the opacity level used for the "light box" effect. Something in the range of 150–200 is probably good. Naturally, you could pick something and hard-code it, but I suffer from severe allergies to hard-coded values. Anyway, it's super easy to call this function from anywhere:
ShowLightBoxedDialog(hInstance, /* your application instance */
MAKEINTRESOURCE(IDD_SAMPLE), /* your dialog template */
hWnd, /* parent window for dialog */
SampleWndProc, /* ptr to dialog procedure */
175); /* light box opacity level */
Because the code takes advantage of how modal dialogs already work in Windows, the user won't be able to interact with any other pieces of your application until they dismiss the dialog box. And because the "light box" window is positioned on top of everything else, it eats all mouse clicks and prevents setting focus to any other application. But it is trivial to work around using something like Alt+Tab.
So this is not a security feature! It is merely a visual effect!
And because it's just a silly visual effect, it's likely to be a frustrating one for your users. I don't actually recommend using it. But now you know how to do it. Wield such power responsibly, etc.
I have an EDIT control created like this:
hwndEDIT_5 = CreateWindowEx (
0, "EDIT", NULL,
WS_VSCROLL | WS_BORDER | WS_VISIBLE | WS_CHILD | ES_MULTILINE | ES_READONLY,
135, 450, 555, 200,
h2, ( HMENU ) ID_EDIT_CONSOLE,
h1, NULL
);
As you can see it is a read-only EDIT area where multi lines text can be displayed. It is supposed to be a console where I can display some information for users when they use the program. I would like the text area to automatically scroll to the bottom-most entry (the newest one) whenever a new line (or message for an user) is added. I've implemented this:
SetDlgItemText ( h2, ID_EDIT_CONSOLE, ch_s );
SCROLLINFO scr;
SCROLLINFO * scr_p = &scr;
scr.cbSize = sizeof ( SCROLLINFO );
scr.fMask = SIF_RANGE;
GetScrollInfo ( GetDlgItem ( h2, ID_EDIT_CONSOLE), SB_VERT, scr_p );
int mmax = scr.nMax;
scr.fMask = SIF_POS;
scr.nPos = mmax;
SetScrollInfo ( GetDlgItem ( h2, ID_EDIT_CONSOLE), SB_VERT, scr_p, TRUE );
That code is scrolling vertical scrollbar to the end of an EDIT control after adding new msg and it works great, the scrollbar gets scrolled but the text still remains visible from the beginning - it rewinds to the beginning after addition while scrollbar rewinds to the bottom. How to make it properly?
Last but not least - this is might be important - in order to display a message firstly I capture the text that is already displayed by using:
GetDlgItemText ( h2, ID_EDIT_CONSOLE, buf, len + 1 );
then I convert buf into string and add to that string a new message that I want to display. Then I convert it back to char array and set it up with SetDlgItemText. I seperate lines by using \r\n. I've coded it that way because I didn't know how to add a line to an EDIT control in different way than using SetDlgItemText. And it adds only one entry AFAIK - if used twice I will not come up with two entries added to an EDIT control, but the first one will get replaced by second function call.
Don't use SetScrollInfo. Use SendMessage() with the EM_LINESCROLL message, sending the message to the edit control's window handle.
SendMessage(MemoHwnd, EM_LINESCROLL, 0, NumLinesToScroll);
The documentation says:
The control does not scroll vertically past the last line of text in the edit control. If the current line plus the number of lines specified by the lParam parameter exceeds the total number of lines in the edit control, the value is adjusted so that the last line of the edit control is scrolled to the top of the edit-control window.
I had the same problem and solved it with Jerry Coffin's answer and some research.
This is the way I use now:
string text = "Append this text";
SendMessageA(hEdit, EM_SETSEL, 0, -1); //Select all
SendMessageA(hEdit, EM_SETSEL, -1, -1);//Unselect and stay at the end pos
SendMessageA(hEdit, EM_REPLACESEL, 0, (LPARAM)(text.c_str())); //append text to current pos and scroll down
If needed: To scroll at the end of Edit Control without appending text:
SendMessageA(hEdit, EM_SETSEL, 0, -1); //Select all.
SendMessageA(hEdit, EM_SETSEL, -1, -1);//Unselect and stay at the end pos
SendMessageA(hEdit, EM_SCROLLCARET, 0, 0); //Set scrollcaret to the current Pos
You can add text by setting the beginning and end of the selection to the end of the text in the control (EM_SETSEL), then replacing the (empty) selection with your new text (EM_REPLACESEL).
Scrolling to the bottom can be done with EM_SCROLLCARET after the caret (the selection) is at the end of the text. There are other ways, but if you're doing it immediately after adding text, this is probably the easiest.
in my case I had a multi line string and Ken White's idea worked very well:
HWND hEdit = this->GetDlgItem(IDC_EDIT_LOG)->m_hWnd;
if (hEdit)
{
int lineCount = m_strClientLog.Replace(_T("\n"), _T("\n"));
::SendMessage(hEdit, EM_LINESCROLL, 0, lineCount);
}
for MFC projects you can use:
mLoggingTextCtl.SendMessage(EM_SETSEL, 0, -1); //Select all.
mLoggingTextCtl.SendMessage(EM_SETSEL, -1, -1);//Unselect and stay at the end pos
mLoggingTextCtl.SendMessage(EM_SCROLLCARET, 0, 0); //Set scrollcaret to the current Pos
I've been searching the net for different things about the win32 API, but it seems all information on it is rather sparse.
I am looking to create a simple window that shows a list of items, however I want to display different columns of data for each item, in a table-style format, where the user could perhaps be allowed to resize the different column widths.
If at all possible, I'd like to also be able to change the background colors of different rows, in the code, between just a general white, red, yellow, or green.
And the user would also be allowed to right click different rows, and be able to call a function on them, or copy the data to the clipboard (but that part is a different story).
Now, I've found list-viewer objects(?) that can be placed in the window, buttons, and right-click menus... but I cannot figure out how to do a table, using the Win32 API. I haven't even really read up on background colors for anything other than the window itself, either.
Is there a different, better framework I should use for this, or are there some functions or items that I've been missing? All help or guidance on the idea would be appreciated...
I'm using MSVC++ to do... everything that I'm working on.
Using the windows API and the standard control ListView you can do a table using the style LVS_REPORT
documentation link - unfortunatelly with no code :( -
About List-View Controls
I've found this good article Windows Programmierung: List View
the explanation is in german language but a google translation together with the code should be enough to understand it. From the article, to create the window:
#include "commctrl.h"
InitCommonControls();
hwndList = CreateWindow(WC_LISTVIEW, "",
WS_VISIBLE|WS_BORDER|WS_CHILD | LVS_REPORT | LVS_EDITLABELS,
10, 10, 300, 100,
hWnd, (HMENU)ID_LIST, hInst, 0);
then it is explained how to create the columns in the method
int CreateColumn(HWND hwndLV, int iCol, char *Text, int iWidth)
how to insert an item (one column)
int CreateItem(HWND hwndList, char *Text)
or insert item with two columns
int Create2ColItem(HWND hwndList, char *Text1, char *Text2)
etc...
Windows provides a fairly basic collection of built-in controls, listed here.
If you want something more sophisticated your options are:
Code it yourself. You have to paint it yourself, handle all the user-interaction, the scrolling, etc. This is a big job.
Find an existing implementation.
Abandon VC++ and use WinForms or WPF.
If you're stuck with VC++, The Grid Control and The Ultimate Grid are MFC-based.
If you're not using MFC there's BABYGRID or The Win32 SDK Data Grid.
If none of them suit, you'll have more luck searching for "grid" than "table".
For Listview examples, nothing beats the clarity of the Classic Sample!
In the meantime, Google Translate along with Unicode + tiny modifications to the rescue for #Alejadro's German link for the Listview- there's no direct translation on offer from search results as the page doesn't contain the appropriate meta tag. Snipped a little for brevity:
Subsequent changes of styles
The style of a ListView can be changed after creation. For this the functions GetWindowLong and SetWindowLong are used. About masks different styles can be defined.
Mask.................................Masked Styles:
LVS_TYPEMASK..............LVS_ICON, LVS_LIST, LVS_REPORT and LVS_SMALLICON
LVS_ALIGNMASK.............LVS_ALIGNLEFT and LVS_ALIGNTOP
LVS_TYPESTYLEMASK...LVS_ALIGNLEFT and LVS_ALIGNTOP but also VS_NOCOLUMNHEADER and LVS_NOSORTHEADER
For the following sequence, dwView contains the style to use, such as LVS_REPORT or LVS_ICON.
DWORD dwStyle = GetWindowLong(hwndLV, GWL_STYLE); // get current style
if ((dwStyle & LVS_TYPEMASK)! = dwView) // only on change
SetWindowLong(hwndLV, GWL_STYLE, (dwStyle & ~ LVS_TYPEMASK) | dwView); }
Control of the ListView control
Generating a list
A list view is created with the CreateWindow function. The window class uses the constant WC_LISTVIEW. To do this, the common control header file must be included.
#include "commctrl.h"
InitCommonControls();
hwndList = CreateWindow(WC_LISTVIEW, "",
WS_VISIBLE | WS_BORDER | WS_CHILD | LVS_REPORT | LVS_EDITLABELS,
10, 10, 300, 100,
hWnd, (HMENU) ID_LIST, hInst, 0);
In the dialog, it is simply defined in the resource.
If there are unresolved externals, you should check whether the library for the Common Controls (comctl32.lib) is included.
Columns of the ListView
Before something can be inserted in a REPORT, the columns must be defined. A column is described by the structure LVCOLUMN. The following routine creates a column.
int CreateColumn(HWND hwndLV, int iCol, char * text, intwidth)
{
LVCOLUMN lvc;
lvc.mask = LVCF_FMT | LVCF_WIDTH | LVCF_TEXT | LVCF_SUBITEM;
lvc.fmt = LVCFMT_LEFT;
lvc.cx = iWidth;
lvc.pszText = text;
lvc.iSubItem = iCol;
return ListView_InsertColumn(hwndLV, iCol, & lvc);
}
The columns can be modified by messages to the ListView or by calling macros that will ultimately execute a SendMessage.
Message Macro call Function
LVM_INSERTCOLUMN ListView_InsertColumn(HWND, int, LVCOLUMN * ) Insert column
LVM_DELETECOLUMN ListView_DeleteColumn(HWND, int) Delete column
LVM_GETCOLUMN ListView_GetColumn(HWND, int, LVCOLUMN * ) Get properties of the column
LVM_SETCOLUMN ListView_SetColumn(HWND, int, LVCOLUMN * ) Change properties of the column
LVM_GETCOLUMNWIDTH ListView_GetColumnWidth(HWND, int) Determine column width
LVM_SETCOLUMNWIDTH ListView_SetColumnWidth(HWND, int, int) Set column width
Insert a line
An element of the ListView is described by the structure LVITEMW (see below). Each element can be represented as an ICON, SMALLICON, LIST element or as the left column of a REPORT line.
int CreateItem(HWND hwndList, wchar_t * text)
{
LVITEMW lvi = {0};
lvi.mask = LVIF_TEXT;
lvi.pszText = text;
return ListView_InsertItem(hwndList, & lvi);
}
The mask field determines which elements of the LVITEMW structure are really used. Since it often makes sense to keep a pointer to the memory object that holds the data behind the object, the lParam field is useful. In order for this to be used, LVIF_TEXT | LVIF_PARAM must be set as a mask.
The constants of mask and the fields that enable them:
LVIF_IMAGE iImage
LVIF_INDENT iIndent
LVIF_PARAM lParam
LVIF_STATE state
LVIF_TEXT pszText
The further columns of a report
The element itself is always left in the report view and is selectable. To fill more columns, a text is added to the item.
int Create2ColItem(HWND hwndList, wchar_t * Text1, wchar_t * Text2)
{
LVITEMW lvi = {0};
int Ret;
// Initialize LVITEMW members that are common to all items.
lvi.mask = LVIF_TEXT;
lvi.pszText = Text1;
Ret = ListView_InsertItem(hwndList, & lvi);
if (Ret >= 0)
{
ListView_SetItemText(hwndList, Ret, 1, Text2);
}
return Ret;
}
The above Create2ColItem is best demonstrated by something along the line of the following statements:
LVHwnd = Your_Create_LV_Routine();
if (LVHwnd)
{
CreateColumn(LVHwnd, 0, ptrColHeaderString1, iColSize1);
CreateColumn(LVHwnd, 1, ptrColHeaderString2, iColSize2);
Create2ColItem(LVHwnd, ptrItemText1, ptrItemText2);
}
The structure LVITEMW
The structure LVITEMW (in CommCtrl.h) describes an element of the ListView. The most important elements are briefly described here. First the definition:
typedef struct tagLVITEMW
{
UINT mask;
int iItem;
int iSubItem;
UINT state;
UINT stateMask;
LPWSTR pszText;
int cchTextMax;
int iImage;
LPARAM lParam;
#if (_WIN32_IE >= 0x0300) //historical note for IE3 users!
int iIndent;
#endif
#if (NTDDI_VERSION >= NTDDI_WINXP)
int iGroupId;
UINT cColumns; // tile view columns
PUINT puColumns;
#endif
#if (NTDDI_VERSION >= NTDDI_VISTA)
int* piColFmt;
int iGroup; // readonly. only valid for owner data.
#endif
} LVITEMW, *LPLVITEMW;
The LVM_GETITEMW and LVM_SETITEMW messages change the attributes of an element. As a parameter, you get a pointer to a LVITEMW structure next to the HWND of the ListView, which must be filled in advance.
The structural elements in detail:
Mask:
Specifies which elements are used. A combination of the following flags is possible:
LVIF_IMAGE iImage
LVIF_INDENT iIndent
LVIF_PARAM lParam
LVIF_STATE state
LVIF_TEXT pszText
iItem
Index (0-based) of the item to which the structure relates.
iSubItem
Index (1-based) of the subitem to which the structure relates. 0 if the structure refers to an item instead of a subitem.
pszText
points to a null-terminated string. If the value is LPWSTR_TEXTCALLBACK, it is a callback item. If this changes, pszText must be set to LPSTR_TEXTCALLBACK and the ListView informed by LVM_SETITEMW or LVM_SETITEMTEXT.
pszText must not be set to LPWSTR_TEXTCALLBACK if the ListView has the style LVS_SORTASCENDING or LVS_SORTDESCENDING.
cchTextMax
Size of the buffer when the text is read.
iImage
Index of the icon of this element from the image list.
lParam
32-bit value that is specific to this element.
Actions with elements
LVM_INSERTITEM Insertion of an element
LVM_DELETEITEM Delete an element
LVM_DELETEALLITEMS Delete all elements
LVM_GETITEMW Read properties of the element
LVM_GETITEMTEXT Read text of the element
LVM_SETITEMW change
LVM_SETITEMTEXT Change to the text
Before inserting multiple items, an LVM_SETITEMCOUNT message will be sent to the ListView indicating how many items will ultimately be contained. This allows the ListView to optimize its memory allocation and release. How many elements a ListView contains can be determined with LVM_GETITEMCOUNT.
Editing selected elements
int Pos = -1;
LVITEMW Item;
Pos = ListView_GetNextItem(hwndList, Pos, LVNI_SELECTED);
while (Pos> = 0)
{
Item.iItem = Pos;
Item.iSubItem = 0;
ListView_GetItem(hwndList, & Item);
TuWasMitElement((Element Type * ) Item.lParam);
Pos = ListView_GetNextItem(hwndList, Pos, LVNI_SELECTED);
}
Events
The ListView sends WM_NOTIFY messages to the parent window. The code can take the following values:
Message............ Description
LVN_BEGINDRAG.............Start a drag-and-drop action
LVN_BEGINRDRAG..........Start a drag-and-drop action with the right mouse button
LVN_BEGINLABELEDIT....Start editing a label
LVN_ENDLABELEDIT.......End edit of a label
LVN_DELETEITEM..........Reports that the item is deleted
LVN_DELETEALLITEMS..Reports that all items are deleted
LVN_COLUMNCLICK......Indicates that the user clicked in the header of a report display
LVN_GETDISPINFO.......The control requests information about the presentation from the parent window
LVN_SETDISPINFO.......The information of the parent window for the item must be renewed
LVN_INSERTITEM..........Indicates the insertion of an item
LVN_ITEMCHANGED.....Indicates that an item has been changed
LVN_ITEMCHANGING....Indicates the intended change of an item
LVN_KEYDOWN.............Key was pressed
Editing the labels
The list view must have been created using the LVS_EDITLABELS style. Then a label can already be clicked on and inputs are accepted. However, the input is discarded immediately afterwards. To allow changes in the label, you just need to catch the WM_NOTIFY and return TRUE. In order to access the entered text in between, access is made to the text of the item. The example shows the input in a message box.
case WM_NOTIFY:
switch (((LPNMHDR) lParam) -> code)
{
case LVN_ENDLABELEDIT:
pItem = (NMLVDISPINFO) lParam;
MessageBox (hWnd, pItem-> item.pszText, "entry", MB_OK);
return TRUE;
If editing was aborted, the pszText element will be 0.
If you want to prevent editing, the message LVN_BEGINLABELEDIT is caught and returned TRUE. Here, too, the item can be accessed in the same way via lParam and thus, for example, a certain item group can be excluded.
Click on the column header in the ListView
case WM_NOTIFY:
switch (((LPNMHDR) lParam) -> code)
{
case LVN_COLUMNCLICK:
ColumnNr = ((LPNMLISTVIEW) lParam) -> iSubItem;
.....
Selection Event
The LVN_ITEMACTIVATE event is sent when the user activates an item. As with the other ListView events, it achieves the window function as part of a WM_NOTIFY message.
case WM_NOTIFY:
switch (((LPNMHDR) lParam) -> code)
{
case LVN_ITEMACTIVATE:
HWND hwndFrom = (HWND) ((LPNMHDR) lParam) -> hwndFrom;MarkedItemIndex =
ListView_GetNextItem(hwndFrom, -1, LVNI_SELECTED);
.....
The LVM_GETSELECTEDCOUNT message can be used to determine how many items have been activated. The LVM_GETNEXTITEM message is sent with the LVNI_SELECTED attribute and all items have been edited.