Here' s my code to draw a single line on a windows form.
Dim myPen As New System.Drawing.Pen(System.Drawing.Color.Red)
Dim formGraphics as System.Drawing.Graphics
formGraphics = Me.CreateGraphics()
formGraphics.DrawLine(myPen, 0, 0, 200, 200)
myPen.Dispose()
formGraphics.Dispose()
I would simply like to erase it now. I've read that the best way to do this is to re-draw the whole form, or to delete the line object..etc..
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If System.IO.File.Exists(FILE_NAME) = True Then
Dim lines As New List(Of String)
Dim text As Array = File.ReadAllLines(FILE_NAME)
lines.AddRange(text)
[Code]...
i get this error Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index
for the line lines.RemoveAt(lines.IndexOf(ListBox1.SelectedIndex))
I've been looking through the FCL for a method that will allow me to erase a line of text from a text file and replace it with another line of text. Neither the StreamReader nor StreamWriter have a method for replacing or removing Text from a text file, as does the string object. Are there any available methods for erasing just certain lines of text from a file, and then replacing them with others?
In my code, I'd like to locate a certain line in the text file, and then at that point in the text file, use a For...Next Loop to replace each successive line of the text file with new text:
Dim user_data_file As String = "user_data.txt"
edit_input = New StreamReader(user_data_file)
Dim edit_line As String = edit_input.ReadLine
[CODE]...
However, I can't find any methods that will allow me to do this.
I'm working on an application with multiple forms. On the first form, the user clicks a button and a simple shape is drawn in a picturebox.Depending on which shape is drawn, a value is assigned to a global variable called baseShape. I want that shape to be drawn automatically on the next form when that form is shown. I haven't been able to find any discussion on "passing graphics" from one form to another.[code]...
View 3 RepliesWe are using a ribbon control from a 3rd party that has a bug. When you click on another app, fragments of our software still shows on the screen. The company that makes the ribbon is working on a patch, but I would like to get the app working while we are waiting. how to force windows to repaint the client area behind the form when the form is deactivated?
I've searched and been reading through posts, but most everyone wants to repaint portions of their app. I want windows to redraw what should be there when my app isn't in front anymore.
1) I still don't know how to link how to link form 1 and form 2...(can we link or NOT??)
2) How to create button erase the answer in form?
3) How to link micrososft access n vbnet?
4) How to create button next n go to the next form?(ex: from form 1 to form 2).
The VB2K8 Express IDE is hanging intermittantly when I click on the form's Design tab. The tab's work area goes blank and a wait cursor appears. I can't switch tabs or do anything else within the IDE at this point. I have to go to the Task Manager, end the VB taskk, and restart the IDE. VB is at SP 1 with .NET 3.5. I have no third party add-ins or controls except for the Visual Basic Power Packs which aren't being used. At this point it is annoying and I haven't lost anything yet but it is happening more frequently over time.
View 4 RepliesI have a component which hooks up with the paint event of assigned control and draws on its surface, Whenever i make any changes to the component i need to resize the form or control at design time in order to see the changes.
I want to ask if there is any other way to refresh the contents of a control at design time which forces it to redraw.
I have some problems. I wantd to convert come vb codes into vb net.
1. I have this VB 6 code:
Public Type ddt
x As String
End Type
I have convertid it in this way:
Public Structure ddt
[Code]...
i would like to be able to erase a graphic that was created.I would like to not have to redraw the graphics minus the graphic thats unwanted.Is there a way to delete a graphic?
View 1 RepliesI have 100 textboxes with different numbers on them how can i erase theses numbers all together not like this textbox1.text = "" Erase numbers with one click?
View 39 RepliesMy program uses OCR dll to get text from other program. It copy and paste text to a text box. Can someone give me a code that will erase everything exept numbers or ".
View 2 RepliesI'm having some trouble getting my button to erase the text that is in the textboxes when I hit it. I thought it would be something like txtAnswerText.Text = "" in side of the Next1_Click sub but that didn't do anything at all.
View 1 RepliesHow do I erase the selected rectangle away?
Private Sub PictureBox1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseDown
m_drawing = True
[code].....
I am using this code to draw a line on a form using textboxes as the x and y coordinates. I then click the button with the code below that will draw the line.
Before the new line is drawn, I would like to have previous lines deleted first.
How can I delete these lines?
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim canvas As New ShapeContainer
[Code].....
I am writing a VB program that measures the voltage on a circuit and then graphs the voltage value. I read what the voltage is at ever milisecond and load that value into an array and shift all the data one to the right. On each timer tick i regraph the data.
The problem i am having is on each tick i erase the picturebox then i redraw the graph using the new array. Because of this the further out the line is from the start of the drawing processes the less it shows the line. You get a flicker effect. I have been seeing if there are ways to remove the flicker but the few things i have found have to deal with doublebuffered but i do not think that is the issue here. I think i need to find some other way to clear the picturebox.[code]...
I'm trying to do a little remake of the old game Achtung! Die Kurve, which is a snake-like game, but with multiple players trying to corner eachother until one remains. Don't play it, it's way to addictive, thats why I'm doing the remake now, I want to play it with up to 8 players instead of 6.
Now here's the problem: to draw the snake, I just use the GDI+ and make it draw a 3x3 rectangle on the form background. It works fine, until you resize or minimize/maximize or something like that, which causes a complete repaint of the form. This is not a problem... but when I press ALT or TAB, the form repaints.
And even stranger: it only happens the first time I hit each button. I can make it happen twice by hitting ALT and then TAB or vice versa, after that, nothing. I really don't get it, and its driving me crazy. I dont want a game with a splash screen saying 'First hit alt, then tab to start the game. Not at the same time that makes you leave the game.'
I have to automate a program that is outside of my control. The way I'm doing this is to use SendKeys.SendWait("keys") to the other program. The problem is, there are multiple fields that might be active and no way to select a single one with confidence. The fields are all different lengths, so my solution is to copy something really long, copy it to the clipboard, and look at the last character that made it though, so I know which field is selected in the other program. This overrides the clipboard, unfortunately.
[Code]...
I already have code to read ID3v1 and v2 tags. That's not the problem. I open an IOStream, locate the ID3v2 header and pull the bytes out. Handling unicode was a bit of a sod, but I got it working.
What I don't understand is how to remove an ID3v2 tag or write one out. ID3v1 is easy - just truncate the file, then append some bytes. Simple. But ID3v2 tags don't have to be at the start of the file, do they? It's conventional, but by no means mandatory. If I just crop the entire ID3 out of the file, and close the gap, will that work? And then, to write my own tags, should I just write the bytes to the front of the file? Or do I need to update other bits of the file so the player will know where the audio data has moved to?
Also, do I need to use unsynchronisation? How can I tell if I need to?
I've looked on CodeProject; I've googled; and I've read the specification on id3.org - which, by the way, is less than clear! For example, it says that the "Extended header size" can be 6 or 10 bytes in length. So um....how am I supposed to know which one? Is there some magic way of determining how many bytes this value is being stored as?
What I don't understand is how to remove an ID3v2 tag or write one out. ID3v1 is easy - just truncate the file, then append some bytes. Simple. But ID3v2 tags don't have to be at the start of the file, do they? It's conventional, but by no means mandatory. If I just crop the entire ID3 out of the file, and close the gap, will that work? And then, to write my own tags, should I just write the bytes to the front of the file? Or do I need to update other bits of the file so the player will know where the audio data has moved to?Also, do I need to use unsynchronisation? How can I tell if I need to?I've looked on CodeProject; I've googled; and I've read the specification on id3.org - which, by the way, is less than clear! For example, it says that the "Extended header size" can be 6 or 10 bytes in length. So um....how am I supposed to know which one? Is there some magic way of determining how many bytes this value is being stored as?
View 1 Repliessimple question. How do I erase all the rows in the DataGridView? This is the code I got:
[Code]...
It updates the values, but say a row was deleted from the database. It will get rid of all the values in the row, but it will keep a blank row. This results in it throwing this error: System.IndexOutOfRangeException: Index 1 does not have a value.
I have the interesting task of doing some graphs using VB.NET. So far, everything that I´ve been reading about GDI+ and e.graphics whatever is really weird. All I want to do is1) Calculate some coordinates clicking button 12) Click button 2 to draw a line with the numbers from button 13) Click button 1 to get new coordinates5) click button 3 to clear the graph. So I decided to draw everthing on top of a Panel, called panel1. I have a routine that draws on screen called drawlines,
Private Sub drawlines(ByVal g As Graphics, ByVal c As Color)
Dim p As New Pen(c, 1)
g.DrawLine(p, xStart, yStart, xEnd, yEnd)
[code].....
I am having and issue with a VB.NET App that displays data derived from a database in a DataGridView Control. I am retrieving the data into a dataview and then setting the Grid.Datasource = oDView. On most machines it refreshes the data cleanly and quickly as you would expect.
[Code]...
I am using a DrawItem and MeasureItem events to paint a combobox with a DrawMode of OwnerDrawVariable.Basically, I'm trying to have the user highlight a selection with the mouse, and then press the space bar to toggle the Save status of a song list. Then I call the Me.Refresh() event for the form in an attempt to redraw the form and the ComboBox.The problem that I am running into is that only the Combobox itself (not the drop-down area) that is a control on the main form is redrawing, and the text that is behind the mouse-highlighted selection of the drop-down list is not changing from Red to Black as I believe it should. If I move the mouse to another selection, then the color does in fact update.[code]
View 1 RepliesI have a RectangleShape on a form and certain events that invoke the Paint event for the Shape.But it redraws unwantedly when I drag the form to the taskbar or minimize and then maximize it or press the alt or tab key while the form has focus.I do not want this to happen. I have made sure that no other event fires the RectangleShape's Paint() event.
View 5 Repliesi am writting a programm in vb net and i need to erase the detail of file each time when a button click
View 2 RepliesI have started to work some more on my 'shape editor'. If you're not familiar with it,ust imagine the Visual Studio form designer: a 'canvas' (the form) with a bunch of 'shapes' (the controls) that can be selected, moved, resized, etc. I have just finished implementing snapping between shapes and the canvas boundaries. But now I am having some slight issues with painting the snap lines.Just FYI: this is what I mean by snap lines:The blue lines that indicate that the 'buttons' are snapped to each other, and a purple line indicating that button1 is snapped to the boundary.
My shape editor is based loosely on jmcilhinney's 'manipulating GDI+ drawings' codebank entry, and a central idea in that post is to only draw what is necessary. In other words, when I move a shape I could re-draw the entire canvas, but it is much faster and smoother to only re-draw the old and the new location of the shape. Since nothing else has changed, I don't need to draw the rest. So, I simply invalidate the old bounds and the new bounds, and even with a lot of shapes all moving simultaneously it still feels very smooth.
I have developed an application where i am drawing line using the mouse like a pen (it can be of any shape) i want to save the location of the object and redraw it later using the drawn location saved on any xml or text file. Instead of saving the edited image i want to save the location only to save the space in the sql server.
View 2 RepliesI am using a button on a form which creates a chart at runtime when the user clicks the button. it works ok for the first time but when I select the button the second time I get a square diagonal box or indexoutofrange Exception.Note: I have another button that clears the series from the chart before reselecting the button that creates the chart.
Below is the code segment
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Static Dim counter As Integer = 0
[Code].....
I used a picturebox to allow user draw lines by mouse. I used this code in mouse down:
Dim D As New System.Drawing.Pen(DrawingColor, 2)
Dim g As Graphics = PB.CreateGraphics()
g.DrawLine(D, X1, Y1, X2, Y2)
but when a window appear on front of picturebox... its seams that picturebox redraw itself, so drawn lines erased.
