Program - Let The User Draw Lines - Error "NullReferenceExeption Was Unhandled"
May 3, 2010I'm trying to make a paint and im trying to make my program let the user draw lines
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.net - NullReferenceExeption Was Unhandled?
Jul 11, 2011I am struggling with the code when I run it I get this error.
Dim CheckedItems(clbfiles.CheckedItems.Count) As Object
clbfiles.CheckedItems.CopyTo(CheckedItems, 0)
For Each CheckedItem As Object In CheckedItems
[code].....
Make A Program That Will Draw 700 Random Lines On It Initially?
Oct 17, 2010I am currently using Visual Basic 2008 Express Edition.I want to make a program that will draw 700 random lines on it initially. I tried my code but the lines only appear in the same way such as straight line and diagonal line. Here's my code:
Public Class Form1
Private Sub Form1_Paint(ByVal sender As System.Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
[Code].....
.net - NullReferenceExeption Was Unhandled "Object Reference Not Set To An Instance Of An Object"?
May 21, 2012I have a problem sending data to my access database.I get this error
NullReferenceExeption was Unhandled - "Object reference not set to an instance of an object."on this part of my codemaxrows = ds.Tables("asdf").Rows.Count What would that mean?Here is my code :
Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
ID = TextID.Text
FName = Textfname.Text
LName = Textlname.Text
[Code]...
Error = NullReferenceException Was Unhandled By User Code?
May 11, 2011Error occuring at line: SqlDataSource3.UpdateParameters("TechID").DefaultValue() = CInt(technicianRow("TechID"))
Here is full VB code:
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Error : ArgumentOutOfRangeException Was Unhandled By User Code Value Of '-1' Is Not Valid For 'Value'
Mar 27, 2011I Was Coding A Tabbed Web Browser With A Progress Bar In Visual Basic 2010 Express Edition. I Started De-Bugging The Browser When It Pointed To This Sub: Private Sub Loading(ByVal sender As Object, ByVal e As Windows.Forms.WebBrowserProgressChangedEventArgs)
ToolStripProgressBar1.Maximum = e.MaximumProgress
ToolStripProgressBar1.Value = e.CurrentProgress
End Sub
And Showed This Error Message: ArgumentOutOfRangeException Was Unhandled By User Code Value of '-1' Is Not Valid For 'Value'. 'Value' Should Be Between 'Minimum' And 'Maximim'
Forms - RichTextBox User Control On Main Form - Error: StackOverflowExecption Was Unhandled
Apr 7, 2011What I have is a user control that has two RichTextBoxes. In the user control, there is RichTextBox1's TextChanged event, I want it to set RichTextBox2's Text to the same as RichTextBox1's Text, I'm currently using: RichTextBox2.Text = RichTextBox1.Text. The user control is on the main form, when I run the application and type I get this error: StackOverflowExecption was unhandled. [Code]
View 4 RepliesError While Running Compiled Program - Unhandled Exception Has Occurred In Your Application
Jun 30, 2010I'm making a program from witch one could run an application with different credentials.I can compile the program successfully, but when I press the button to run the program I get the following error: Unhandled exception has occurred in your application. If you click Continue, the application will ignore this error and attempt to continue. If you click Quit, the application will close immediately.The system cannot find the specified file.The code behind the button is as follows:
Dim myProcess As System.Diagnostics.Process = New System.Diagnostics.Process()
myProcess.StartInfo.FileName = "c:
un.bat /user:kreathyr c:getlogin.exe"
myProcess.Start()
Getlogin.exe does nothing but show the logged in username and run.bat utilizes the runas command.
.net - Graphics.drawString - Draw String In Multiple Lines And Know How Many Lines Given String Will Take
Aug 26, 2011I want to draw string in multiple lines and and I want to know how many lines given string will take. I am using following method.
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System.Data.OleDb.OleDbException Was Unhandled By User Code ErrorCode=-2147217900 Message=Syntax Error In INSERT INTO Statement
Jul 8, 2011I cannot seem to figure out why VB keep throwing me this exception but here is the code
[Code]...
Draw Lines In A Picturebox?
Oct 25, 2008I'm making the transition from VB6 to VB2008 and I'm having difficulty finding the equivalent to[code]...
It seems in VB2008 I can only use pens inside a picturebox1_onpaint() subroutine, I can't tell a picturebox what to do from a button_click subroutine or form_load subroutine first and then send the results to a picturebox. I have no control over when the graphics are drawn and from which subroutine. How do I solve this in VB2008 ?
Lines Won't Draw To Picturebox?
Apr 11, 2009I have a simple picturebox, line drawing procedure (call it "DrawTheLine"), which fires ok when I call it from a command button. But when I try to call it from the boot form_load procedure it doesn't work; no lines draw. No errors are raised.
Things I've thought of are:
1. The form_load procedure is not done creating all of the controls on the form, so it can't work with them yet. Doesn't make sense because my drawing call is the last thing in the form_load procedure, and it executes, but the picturebox does not show the lines.
2. Tried Application.DoEvents, but no go.
3. Tried using picturebox.invalidate to force a paint event and "called" the drawing procedure that way, with the appropriate arguments. Again, the procedure "DrawTheLine" fires, but no lines draw to the picturebox.
Trying To Draw Lines On A Userform?
Sep 21, 2011I have the following form:I want to join the boxes so that it looks like this: would rather create the lines on the userform manually but I do not think there is a way to do it. I've tried the following code but I cannot see the line:
Private Sub DrawLine(ByVal X_From As Integer, ByVal Y_From As Integer, ByVal X_To As Integer, ByVal Y_To As Integer, _
ByVal Line_Width As Integer, ByVal Line_Colour As System.Drawing.Color)
[code]....
Use A Picture Box To Draw The Lines?
Jun 12, 2011Iam doing a sample project for school and i CHOSE Tic Tac toe. sample program of it becuase i have no idea where to start. And do I use a picture box to draw the lines?
View 1 RepliesWay To Draw Dashed Lines
May 29, 2009I need to draw dashed lines. I use this code:
Dim MyPen As Pen = New Pen(Color.Black, MyWidth) With {.DashStyle = Drawing2D.DashStyle.Dash}
MyGraphics.DrawLines(MyPen , MyDots.ToArray)
But since the distance between successive lines it too short, the dashes start each one too near to the last. It causes a continuous black line
Draw 2 Lines In The Center Of The Screen?
Aug 24, 2009How would I do this? I want my Program to draw 2 lines in the center of the screen.
View 3 RepliesDraw Lines By Mouse Move?
Apr 25, 2009I can draw one line by mouse moving on a form, but i used cls function to clear screen when move mouse (otherwise it wont show single line when move mouse), so i cudnot draw next line with out clearing previously drawn line, kindly help how to solve this problm
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Draw Lines In Highlight Pen Style?
Aug 19, 2011I am making a drawing application (Graphics class), with a highlight pen and a calligraphy tool. But the pen tip should not rotate according to the line direction. I have tried the CustomLineCap, but still not working.
View 3 RepliesDraw Lines Inside Circle?
Feb 2, 2011How to draw lines inside the circle. I mean a circle with n-number of lines within in it.
View 7 RepliesDraw Lines With Button Click?
Nov 1, 2009Firstly I am using Vb 2008 Express Edition.I have the following code:
Code:
Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e _
As System.Windows.Forms.PaintEventArgs) Handles PictureBox1.Paint
Dim x1 As Integer = 0
Dim x2 As Integer = 50
[code]....
When I run the above code it works , no problem. But I want to trigger it only on my Button_click event.
Code:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
End Sub
I don't know how to call the PictureBox1_Paint into my Button1_Click
Draw Zebra Lines In Form
Jun 20, 2012i want to "draw" zebra lines in my form [code] ican import background image, but I prefer code :)
View 1 RepliesIDE :: Draw Lines And Shapes On A Form?
Feb 15, 2006The image editor toolbar is not active. I would like to draw lines and shapes on a form.
View 1 RepliesVS 2008 Draw Lines In VB Form?
Apr 5, 2010I need to draw lines, in one VB form. Like paint, I need the tool brush, and design some lines and curves in a Vb form. How can I do this? I don't know where to start.
View 3 RepliesVS 2008 Draw Lines Using DirectX?
May 1, 2010How do I draw lines using DirectX? (on my form)
View 1 RepliesDraw A Grid Using Vertical And Horizontal Lines
Dec 7, 2011I'm trying to draw a grid using vertical and horizontal lines.Both For..To statements work fine when one of them is commented out otherwise, they won't work together. At run, only the first For..To statement is executed.[code]
View 6 RepliesDraw Text Oriented Along The Direction Of Each Of These Lines?
Nov 6, 2011I have some lines drawn in many different directions (2D y 3D enviroments). Is there any way to draw text oriented along the direction of each of these lines? It was an easy task in former versions of Visual Basic, but now it looks like a very tough -almost impossible- mission.
View 4 RepliesUse Lines To Draw Geometric Figures(Polygons)?
May 9, 2012I'm trying to do something that is turning out to be out of my league at the moment. I need to draw geometric figures. These geometric figures have all the coordinates of their corners. Say I have a trapezoid, and I would want to draw it. The drawing would be done in a picturebox or a panel or a groupbox (some part of the form where only the geometric figure will be).
I saw the method on how to do that Here and that's exactly what I'm trying to achieve, but there it's drawn on a newly created form, and I need it in a picbox, panel or groupbox as I mentioned above. I also need the drawn figure to be at the center of the picbox/panel/groupbox.
The coordinates of the lines should be like (xa.text,ya.text) to (xa.text - xb.text, ya.text + yb.text) if I'm not wrong for the first line of the geometric figure and so on.
Draw Lines Like These Ones At Top (underneath The White Box) And Bottom (above The Buttons)?
Mar 4, 2009How do I draw lines like these ones at top (underneath the white box) and bottom (above the buttons) - preferably in the GUI?
View 6 RepliesHow To Draw Empty Lines Instead Of Blank Area In DataGrid
Nov 20, 2011I think we can just draw an image that resemble the grid using this article : drawing in a datagridview Currently creating a way to make the image drawn in tile mode. Each time I develop a datacentric application using VB.NET regardless of how much the data displayed in the datagrid, I always want the grid to display full row of empty data, not just blank panel. Can we achieve this using VB.NET design time property? And also, we must not trigger the display of vertical scrollbar this way..
View 1 RepliesUnable To Display A World Map And Draw Lines Between Cities?
Oct 22, 2009I've got a project where I want to be able to display a world map and draw lines between cities.I've looked at using a web browser with google maps but don't want it to have to be used while "online"
I've looked and longitude and latitude and converting these to UTM co-ordinates but i'm lost for how to place these on world map programaticly.I have a full list of all cities used in my program and have a list of their latitude and longitude co-ordinates because i need to work out thier distance apart which I have already done the code for.
