CODEWITHSUNDEEP
c++ctextboxricheditrichedit-control
user1397417
user1397417

Reputation: 738

how to auto scrolldown a richedit textbox win32 c/c++

here is my code that appends messages to the richedit text box:

CHARFORMAT cf;
memset( &cf, 0, sizeof cf );
cf.cbSize = sizeof cf;
cf.dwMask = CFM_COLOR;
if (getuserofmessage(msg) == myname)
cf.crTextColor = RGB(0,0,255);// <----- the color of the text
else if (getuserofmessage(msg) == "admin")
cf.crTextColor = RGB(255,0,0);// <----- the color of the text
else
cf.crTextColor = RGB(55,200,100);// <----- the color of the text

SendMessage( hwnd , EM_SETCHARFORMAT, (LPARAM)SCF_SELECTION, (LPARAM) &cf);

/*SendMessage(hwnd, EM_SETSEL, 0, -1); 
    SendMessage(hwnd, EM_SETSEL, -1, -1); 
     SendMessage(hwnd, EM_REPLACESEL, 0, (LPARAM)msg.c_str());*/
     CHARRANGE cr;
cr.cpMin = -1;
cr.cpMax = -1;

// hwnd = rich edit hwnd
SendMessage(hwnd, EM_EXSETSEL, 0, (LPARAM)&cr);
SendMessage(hwnd, EM_REPLACESEL, 0, (LPARAM)msg.c_str());

and here is the createwindow for the richedit textbox:

hwnd=CreateWindowEx(WS_EX_CLIENTEDGE, RICHEDIT_CLASS, "",                   
ES_READONLY | WS_CHILD | WS_VISIBLE | WS_VSCROLL | ES_MULTILINE | ES_AUTOVSCROLL,
x,
y,
w,
h,
parent,
(HMENU)identifier,
GetModuleHandle(NULL),
NULL);

But it does not automatically scroll down when the messages in the text box become to much to all fit in it, forcing the user to have to constantly scroll down. All of the other references facing this problem are in .NET or c#. Cant i somehow set the cursor to the bottom of the text box after the append? or something like that. any help is appreciated. thanks.

EDIT: I tried adding :

DWORD TextSize;
TextSize=GetWindowTextLength(hwnd);
SendMessage(hwnd,EM_SETSEL,TextSize,TextSize);
SendMessage(hwnd,EM_SCROLLCARET,0,0);

after my append code as this was a solution for someone else but did not work for me

Upvotes: 0

Views: 2114

Answers (3)

k.bon
k.bon

Reputation: 386

delphi try this.

SendMessage(RichEdit1.Handle, WM_VSCROLL, SB_BOTTOM, 0);

Upvotes: 0

user3406468
user3406468

Reputation: 21

SendMessage(hwnd, WM_VSCROLL, SB_BOTTOM, 0L);

after the Text was inserted works best for me.

Upvotes: 2

Mitchell
Mitchell

Reputation: 56

Before you insert the text in,
int start_lines, end_lines; start_lines = SendMessage(hwnd, EM_GETLINECOUNT,0,0);

After text is inserted,
end_lines = SendMessage(hwnd, EM_GETLINECOUNT,0,0); SendMessage(hwnd, EM_LINESCROLL, 0, end_lines - start_lines);

Upvotes: 2

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