how to use DrawText() to write text in a given window whose handle is known?

Question

I want to know how to write text on a particular window starting at a given location in the window using the Windows API.

For example if the coordinates within the window where the text is to be written are (x,y) = (40,10) then what do I need to do to write a line of text to a particular window at that location in the window?

score 14 · Accepted Answer · answered Dec 29 '09 at 10:55

14

Suppose your window name is "hwnd" and the text which u want to write on that window at x,y coordinate is say stored in "message" where

LPCWSTR message=L"My First Window"; then

RECT rect;
HDC wdc = GetWindowDC(hwnd);
GetClientRect (bgHandle, &rect) ;
SetTextColor(wdc, 0x00000000);
SetBkMode(wdc,TRANSPARENT);
rect.left=40;
rect.top=10;
DrawText( wdc, message, -1, &rect, DT_SINGLELINE | DT_NOCLIP  ) ;
DeleteDC(wdc);

Thats it.. remember this is just one example.

answered Dec 29 '09 at 10:55

Abhineet

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3

Shouldn't it be GetDC(hwnd) and ReleaseDC(hwnd,wdc)? At least it only seems to work for me this way. – masterxilo Jul 29 '12 at 22:18
Yes you can do in that way as well. – Abhineet Jul 31 '12 at 09:03
2

What is `bgHandle` in this example? – ST3 Aug 30 '13 at 13:50
@user2623967: here "bgHandle" is a child window of main window i.e "hwnd". Here it is retrieving the coordinates of the child window i.e. "bgHandle" where the text will be displayed. – Abhineet Sep 02 '13 at 04:58
3

Nop! When you use **get** you **release** eg *GetWindowDC()* -> *ReleaseDC()*. When you use **create** you **delete** eg *CreateCompatibleDC()* -> *DeleteDC()* – γηράσκω δ' αεί πολλά διδασκόμε Sep 15 '16 at 10:47

score 4 · Answer 2 · answered Feb 19 '20 at 10:07

I am hoping this a more complete answer...

void OnPaint(HWND hWnd)
{
    RECT  rect;
    PAINTSTRUCT ps;
    HDC hdc = BeginPaint(hWnd, &ps);

    GetClientRect(hWnd, &rect);
    SetTextColor(hdc, RGB(0xFF, 0x00, 0x00));
    SetBkMode(hdc, TRANSPARENT);
    rect.left = 40;
    rect.top = 10;
    DrawText(hdc, L"Hello World!", -1, &rect, DT_SINGLELINE | DT_NOCLIP);
    SelectObject(hdc, oldPen);
    DeleteObject(hPen);
    EndPaint(hWnd, &ps);
}

This would then be called from the WM_PAINT message in the WndProc.

how to use DrawText() to write text in a given window whose handle is known?

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