I have a timer that runs every time by itself, and for the code the runs in it I would like to have it clear the dataset before it does anything, the timer runs every 10 seconds, so I tried to do dataset.clear but it would crash if the dataset had no values
View 4 Repliesthis is currently my code to clear my 5 textboxes
Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
TextBox1.Clear()
TextBox2.Clear()
TextBox3.Clear()
TextBox4.Clear()
TextBox5.Clear()
End Sub
I've always use String.IsNullOrEmpty to check for a empty string. It recently come to my attention that a " " count as not a empty string. For example,
Dim test As String = " "
If String.IsNullOrEmpty(test) Then
MessageBox.Show("Empty String")
[Code]....
It will show "Not Empty String". So how do we check for " " or " " in a string?
edit: I wasn't aware that " " count as character.
I think I've misused this method and would like to know what it actually does.I 've looked it up on msdn forum and found this
[code...]
What does it mean by removing all the rows in all tables? Is it the datagridview table? When it says "removing", does it mean that it deletes everything?
The reason I misused it is because I thought dataset.clear means it flushes the record held in dataset.
When I click on the add new icon on bindingnavigator, a new form will appear, which allows me to insert data
[code...]
when I close the insert form, the parent form will be activated and datagridview will display the new record I just inserted. I thought the dataset.clear method helped display the new added record but then I realised I could do without the dataset.clear method.
[code...]
in hyper teriminal when i press "ctrl+L" is to clear terminal screen how to write the code in vb.net? Hyperterminal is connecting to serial comport.when i try this it work and return line on debug
serialport.writeline ("at+cmgl=1")
i try this but not work and it still show some lines on debug
serialport.writeline (vbcrtl +"L")
serialport.WriteLine("vbCrLf + l")
way to clear textboxes in VB.Net and what is the difference between the two methods? I have also seen people be critical of folk using clear objects on their forms and i can see why but in this case, i am only learning.
txtbox1.Clear()
or
txtbox1.Text = ""
wan to ask about anyone know the code about how to clear all the data inside the data grid view without clear the binding source...
View 1 RepliesIn my winform program (in vb.net) I wrote:
Dim dt As New DataTable
'Get data from DB into dt
'...
[Code].....
But when I run the program, Clear() cleared both dt and dttemp! Why? Aren't dt and dttemp supposed to be two distinct instances of DataTable?
(I finally found a solution - dttemp = dt.Copy() instead of dttemp = dt. But I still can't see why Copy() was necessary in this case.
here is the code, i want to clear just the box with the error in it. if possible and leave the other numbers in put as they where.
Private Sub btnCalc_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalc.Click
' the following declare the values that will be used
[Code]....
Public Sub Clear()
Form_Main.ctl_InspName.Value = ""
Form_Main.ctl_ESN.Value = ""
Form_Main.ctl_ToAProcess.Value = 0
[code]....
I am using the StreamWriter to create a log file for my application. However I do not see a method on how to clear the file (make the file blank again). Also before I clear the file I want to rename it so that I can have multiple log files, a new one produced everytime the application runs.
[Code]...
I have datagridview1 binded to data Table1 (with binding source) . This data table1 is in relation with his child data table2.When I insert new record to table1 I want to refresh datagridview1.
If I use table adapter fill method I get error.TableAdapter1.Fill(Me.DataSet1.Table1) ' error error: Cannot clear table Table1 because ForeignKeyConstraint FK_Table1Table2 enforces constraints and there are child rows in Table2.
I am using the following code to clear all the values of all my controls everytime I click save button....Is there a way to not to clear the value of a certain control inside one groupbox? I would like the radiobutton in one group box will not be cleared...or if it can't be done, how do i put back the selected radiobutton after i click save?[code]....
View 15 RepliesI have the aplication which requires name fields... and i wan tto clear these fields whenever i closed the application using close(X) button. i dont want to use 'clear' button.
View 3 Repliesi m trying to clear my all row in datagridview. Here is simply code
Me.DatabaseDataSet.Clear()
Me.StuffTableAdapter.Update(Me.DatabaseDataSet)
Me.DatabaseDataSet.AcceptChanges()
It's almost clear datagridview, but don't save this changes in base. I quite the app and start it again then old row are back.
I want to have a button that clears all textboxes except three. This code I got so far which clears all the textboxes except 1
[code]....
Is there any built-in function in vb that allows us to be able to delete our bin/obj folders instead of having me manually delete them myself?
View 4 RepliesI need to clear out a pathstring value. I have a command line created from four different text boxes. I have created a button that clears those text boxes, but it does not clear out any data already in the "pathstring". How do I clear it? This is for the coding that executes the pathstring command.
[Code]...
Is there a way to clear out a tool tip?
I have a field where the tool tip data is changed based on what record they select. It's show each record in different tool tips. I just want to show the current one.
Below is my
Dim lblnotes As ToolTip : lblnotes = New ToolTip
lblnotes.SetToolTip(lblequipment, return_notes_stringtooltip())
I am a first year diploma in IT student and have this assignment here. Its for a catering business to calculate simply selections of food etc.So after calculation there is a summary to show total sales, number of sales and average sales. After the person clicks Ok i am asked to give them an option to clear summary.Now i need to know if they click yes how do i clear the summary?
Private Sub summaryButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles summaryButton.Click
'Calculate Average and Display Total Sales
Dim returnDialogResult As DialogResult
[code]....
I've created a bitmap on which I use setpixel to color it in. Then I display it on a picturebox. I want to clear the bitmap form time to time, reset all its pixels. I see no bitmap.clear() method and there's nothing in the documentation that seems. Short of disposing of or setting the bitmap = nothing and creating a new one, how do I wipe a bitmap?
View 8 RepliesHow do I clear a DataGridView? Basically I want the user to be able to click the button again that fills it and it will erase everything and refresh the data.
View 17 RepliesI have a form with a tabcontrol. The tabcontrol has two pages. The first has a form that the user fills and clicks on a button to store the values on a SQL database. The second has a combobox that is filled on the click event of the button with the values of a field of a database table. I put the filling of the combobox on the button's click event in order to display the new (stored) value. The problem is that if the user repeats the above procedure then the displayed values (in the combobox) are doubled, tripled etc. I tried to clear the datatable that I am creating and filling after assigning its values in the combobox but it doesn't work. [Code]
This code is on the button's click event. But it returns an empty combobox. I can't understand why is doing this as first I am filling the combobox with the values from the datatable and then I clear it. Any suggestions for solving the above problem?
I have just moved over to Visual basic 2008 express edition. i want to clear a string and don't know how. the vb6 code was: txt = "" but know i does nothing? what do i do to clear the string.
View 2 RepliesI am using datagridview.rows.clear() to empty a grid that i can't clear it. is there another way to empty the grid?
View 1 RepliesI'm writing a code in which the user is supposed to enter a number less than or equal to 15 and greater than 0.And If user enters a number greater than 15 then he gets an error msg. I do have the right code for error messge but the listbox still shows the result along with the error message box. How do I JUST have the error message.[code]
View 1 RepliesCode is in VB 2008,
In code i am using Datatable, using that select method datarow
Dim dt as New Datatable
Dim dr() as Datarow = nothing
[code].....
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) _
Handles Button1.Click
EmptyTextBoxValues(Me)
End Sub
[CODE]...
This sub is for to clear all textboxes value, i just need to know how did it work ?
With every sheet music file opened, I am also loading background music file, if such exists. If music file doesn't exists, I need to clear the previous one from the sourceURL, otherwise I have wrong music playing with wrong notes. How can I do that?
HTML
Sub Play_BackgroundSoundFile()
Player.settings.autoStart = False
Dim urlpath As String = (Application.StartupPath & "UserMIDILibrary")
Dim fname As String = Path.GetFileNameWithoutExtension(pathload)
fname = fname & ".mid"
[Code] .....
I am filling a datatable and after storing the values I want in two variables I want to clear my datatable or erase it.[code]...
As the above code is in a function (and I am calling this function many times) it causes me problems. The variables id and entitycode store the first values (the first time I run the function) and then it always use them. That's why I want after storing the values in variables to also clear the datatable or even erase it (and rebuild it when I rerun the function).