VB.NET Windows Forms Textbox Scrollbar

Question

I have been trying to solve this problem for past two days., Tried a lot and looked everywhere but could not get solution. What I would like to do is expand the the hight of textbox programmatically , when the text inside a multilne textbox fills up the entire text area. so probably i need to captue an event when the lines wrap or captrue an event when the scrollsbars are enabled ? I do not know what to do to solve the above problem ? please advise.

s_manishkumar · Answer

Thanks for your reply. Let me try accoridng to what you suggested. Actually my original problem will be solved. I have been using datagridtextbox column for grid table style. Now I found something that autosizes the grid rows. Which i think will solve my problem, as it exapnds the whole row based on text content height. Thanks a lot.

sjones · Answer

Not tried or tested but you can look into this. You are not going to get an event for an embedded child control, i.e. the scrollbar. You can only get events from your control, i.e. the text box. I would look into handling the TextChanged event because that is the textboxes only opportunity to change things. See if you can get the internal width of the control. Hopefully that will change once the scrollbar becomes visible because it will eat several pixels. You should look for something like Client Width. Even if you cannot get it from the textbox control, you can get it from the window handle using Win API. So basically you store the initial client width, every time the text changes you look to see if the client width decreases. If it does, you increase the control's height. Remember that when you do that, the scrollbar with go away again so your text will be reformatted again. While writing this it occurs to me that you will be handling the event after the fact and you may get some flickering scrollbar and word wrapping effects. You'll just have to try it and see. Your other alternative, and maybe better approach is to use the API with ExtTextOut. I think that is the function name. It will allow you to create a device context that matches your screen, create and select the font used by your text box, and measure the space it will take to display your text. Then resize your textbox accordingly. But if you go to all that trouble, you might just be better off creating your own custom control that handles all of this stuff.

s_manishkumar · Answer

Hi, Thanks for your reply. I think, what I want is this: probably I have not explanined it well. I want the textbox to expand in height , when the text you are typing in a multiline textbox reaches the right most edge. So ultimately my requirement is "not" to have scorllbars and when the line of text wraps or reaches the right most edge of the textbox, the textbox should expand in height so that I can view all my text clearly in it. So what I thought is if we can capture the event when the line wraps or scrollbar get enabled we can write a logic to increase the height of text box. But somehow I am not finding any way to capture this or to do it any other way. let me know if anybody knows this!

send2manivannan · Answer

Put the Multiline Property to True Put the WordWrap Property to False Put the Scrollbars Property to Both It should Work....

VB.NET Windows Forms Textbox Scrollbar

Answers (4)