How to change scrollbars position in a multiline textbox

Introduction

I have discovered a nice way to control multi-line textbox's scrollbars in C#. Here we can force the textbox's scrolls down to the end of the text, when we are showing the log file contents dynamically.

The code

First, we have to define a constant value:

const int EM_LINESCROLL = 0x00B6;

Then, we have to declare two external methods of user32.dll:

[DllImport("user32.dll")]
static extern int SetScrollPos(IntPtr hWnd, int nBar, 
                               int nPos, bool bRedraw);
[DllImport("user32.dll")]
static extern int SendMessage(IntPtr hWnd, int wMsg, 
                               int wParam, int lParam);

Finally, use these methods to do the real thing:

SetScrollPos(myTextBox.Handle,1,myTextBox.Lines.Length-1,true);
SendMessage(myTextBox.Handle,EM_LINESCROLL,0,
                             myTextBox.Lines.Length-1);

Done! Simple and easy!

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