I am a student programmer who is learning VB. I am trying to make a telephone book type project in VB (Windows Forms). In my project I am using an unbound Data Grid View control. Below the Data Grid View, I have some textboxes which will display the values of the selected row. On the form load event, my program accesses a file and populates the Data Grid View control with values from the file. This works perfectly, but the problem I get is when I use the code:
txtLast.Text = dgvMain.Rows.Item(0).Cells(0).Value
to populate the textbox called txtLast with the value at the specified cell, the textbox doesn't display the value. The program doesn't crash or hang, it simply won't display the value and when I try to edit the textbox, it acts as if the textbox is empty. I have tried using
txtLast.Text = dgvMain.Rows.Item(0).Cells(0).Value.ToString()
as well as trying to refresh my Data Grid View control and the textbox. Nothing has worked so far. When I use a breakpoint to see whether that line of code is executed, the autos window shows me that the line of code is executed and that it sees the value of the specified cell as "Smith". However, when I press F11 to step into the next line, the textbox.text property remains as "" instead of changing to "Smith".
Note: when I manually specify the text through the code (i.e. txtLast.Text = "Test") it will show that text. Also, this problem is not with just one textbox, it is with every textbox that I use (I have 5 textboxes showing various values from the specified row). The weird thing is that out of the 5 textboxes, one of them, the masked textbox which shows the phone number works perfectly with the same line of code. (note it is not a problem only affecting regular textboxes as I have tried using both regular textboxes and masked textboxes, both produce the same problem except for the phone textbox).
Also, I would prefer to keep the Data grid view unbound (not connected to a database) and the textboxes unbound (not connected to the data grid view as a data source) because while browsing the internet I have seen people suggesting to bind the textbox or data grid view, however I do not understand how to do so, and I believe that this can be done without binding to a data source.
Any help is appreciated in trying to figure out why the text doesn't change. Let me know if you need any other info or if part of my explanation is unclear.
Thanks!
Related
I am trying to filter a subform based off a value selected in a listbox.
My list box is called cboCurrentListName and this is populated using a select query
The subform is called Form_subform_ListContents
For the change event for the list box I have the following code, however no filters are applied when its executed.
Me.Form_subform_ListContents.Form.Filter = "[ListName]=" & Me.cboCurrentListName.Value
Me.Form_subform_ListContents.Form.Filter = True
I have also tried using Master/Child links to execute this using the following steps, but this caused an input box to pop up when the fom loaded:
first I set the 'link child fields' option in the properties of the subform to 'ListName' (this is the field name that populates the list box and is present in the subform
then I set the 'link master fields' option in the properties of the subform to 'cboCurrentListName' (the listbox name)
then in the listbox properties I set the control source to 'cboCurrentListName'
The above steps cased an input box to pop up on opening the form (the value typed in here does filter the subform). However I don't want an input box in order to do this, I want to use the listbox.
I have googled this and fried different methods but have had no luck. I am pretty new to access and of the control source sections aren't a strong point of mine, which is why I tried to use the VBA on the event change instead
Any help would be appricaited, I tried a few things and had no luck.
EDIT: When trying the master/hild option I also get an error 'Can'y build a link between unbound forms' if I click the 3 dots in the poperties. SO for the above steps I had to manually type in the otpions.
I have a form frmDetail that contains several locked fields I want populated only when another form has been filled out, in the name of having some kind of standardization in my data. This other form frmSignOut is used to enter in a date and location that will populate the fields on frmDetail. frmSignOut also contains a subform subULookup that looks up users from a different table using an identifier number. The resulting last name, first name and phone # should also be passed to frmDetail. I also hope to combine first and last name somehow into a Last,First format.
My approach so far has been to open frmSignOut modally with acDialog and I inserted Visible=False into the On_Click event on frmSignOut. Then I try to reference my subform fields and set them to the desired fields on frmDetail. I finish by refreshing and then closing the dialog form.
Private Sub CmdSignOut_Click()
DoCmd.OpenForm("frmSignOut"),,,,,acDialog
If CurrentProject.AllForms("frmSignOut").isLoaded=True Then
Set Forms!frmSignOut!SubULookup.PhoneNbrTxt=Me.ContactNbrTxt
DoCmd.Close (acForm), ("frmSignOut")
Me.Refresh
End If
End Sub
I have only been able to get this far, trying to pull the first field PhoneNbrTxt. I can get frmSignOut to open, I put in data and when I click my 'close' command button I get run-time error 438: Object doesn't support this property or method.
The line highlighted is where I try to reference my subform field. I also have a 'Cancel' button added to frmSignOut that just closes the form, I have no errors there.
Again I'm completely new to Access without much prior experience in anything related, I'd appreciate any knowledge you guys can throw at me.
EDIT: I've been able to successfully pull the value to Me.ContactNbrTxt by adjusting my code to the below.
Me.ContactNbrTxt = Forms!FrmSignOut!SubULookup.Form!PhoneNbrTxt
It looks like the missing part was the Form! right before the control name, along with formatting this correctly and dropping Set.
Im still trying to work out how to combine first and last name before also pulling those to frmDetail, if anyone can help there.
I inherited a fairly large project at work that is undocumented and written in VB (originally started pre .NET, ended around .NET 2). I'm in the process of updating / refreshing a lot of the code, but have run into an annoying issue that I haven't found the solution for yet. This system utilizes a UI, a Web Service, and a SQL DB.
Problem: I have a Databound Combobox (originally set to DropDownList - I'm changing it to DropDown, which is what started this mess - going back isn't an option) that is tied to a DataSet that comes from a Web Service. When a user types in the item they want manually, the data from the text field doesn't seem to associate itself with the DisplayMember, which forces the WS/SQL query to fail (it is sent a blank value when it's expecting a ValueMember). If the user types in a partial selection and then chooses the value they want from the DisplayMember list using the arrow keys or tab, the query goes off without a problem.
My Question: How do I get the text field to translate to the DisplayMember which will then properly tie itself to the ValueMember which will then allow the query to execute correctly? Sorry for making this sound complicated or convoluted; I'm sure the answer is easy and I'm just glazing over it.
The relevant bit of code is:
With cmbDID
If dtsLU.Tables.Contains(reqTable) = True Then
.DataSource = dtsLU.Tables(reqTable)
.DisplayMember = "zip"
.ValueMember = "gridID"
End If
End With
cmbDID.DataBindings.Clear()
cmbDID.DataBindings.Add("SelectedValue", dtsData, strDT & ".gridID")
I've tried changing "SelectedValue" to "Text", which almost works - but it directly translates to gridID and skips zip which ends up with an incorrect Web Service response since the zip and gridID field values are not synced (zip (DisplayMember) may be 5123 while gridID (ValueMember) may be 6047). I've tried changing "SelectedValue" to "SelectedIndex", and that got me no where.
Any help is greatly appreciated.
EDIT
To add some clarification to the process, the below pseudo code / description is roughly what happens. I could post the whole module, but I feel that would just muddy the whole question even more.
Private Sub A
FormAlpha is created with 1 ComboBox in the form of a DropDown
This DropDown is populated with a DataSet
DataBinding with a blank DataSet is added to the control to keep track of the users input
End Sub
lblSubmit_Click event is triggered on FormAlpha by the user after they have populated the DropDown with their data. lblSubmit_Click calls Private Sub Submit
Private Sub Submit
BindingContext(DropDown DataSet, tableName).EndCurrentEdit() is called
DataSet.HasChanges() is processed
If changes are present, changes are processed
HERE lies the problem
If the user has manually typed in the DropDown field, but not hit an arrow key or tab, then the DataSet registers a change, but returns a null value in all fields - it knows something was entered, but that data apparently didn't pass through the DataSet for the ComboBox (ListItems or SelectedIndex didn't change / fire I'm guessing). If the user selects the item with the arrow keys, the DataSet has the proper input (I'm assuming the Data was validated by the control at this point).
If the processed data is good, a value is entered into the database
If the processed data is bad (empty), an error is returned
End Sub
If the above can't be solved with what I've provided, but someone still knows a better way to handle this type of situation, I'm all ears. Rewriting the module isn't ideal, but fixing this problem is a necessity.
Alright, while this fix may not be ideal, it is a fix none the less.
The bare bones problem was that the text value of the DropDown wasn't causing the data to actually affect the SelectedIndex / SelectedValue of the control unless you interacted with it using the arrow keys or a mouse click. So, while the DropDown would read "1234", in reality the control saw "".
The fix I have in place for this is simply calling comboBox.text = comboBox.text whenever the user hits the submit button.
I have a question, I have a combo box, which when changed fills the data grid. Now Wen I change the Tab and come back to same tab again(one containing the combo box)..the value of combo box remains there, however the grid gets empty. I need this data to be maintained till the user selects another value from drop down.How can this be done???
Any suggestions would be appreciated.
Some of the possible reasons :
There is a MyDataGrid.clear somewhere
The DataSource used to fill the grid is somewhere cleared.
If you use a DataSet, your DataTable is somewhere truncated.
If you use a BindingSource as your DataSource, maybe somewhere else you're using the same BindingSource, which empties the grid.
I would recommend you to put a braekpoint on your Combobox change value event to see if it's not called with a wrong value somewhere else.
And I would add a spy to check your DataGrid (the number of lines for example) to precisely know where it happens by executing my code step by step.
Hope this helps !
Code in Form onLoad:
country_combo.RowSourceType = "Value List"
Code in a reset function:
Dim lListIndex As Long
With Me.country_combo
For lListIndex = .ListCount - 1 To 0 Step -1
.RemoveItem (lListIndex)
Next lListIndex<br/>
End With
Code to populate country combo:
*For n = 1 To numCountries*
*countryCombo.AddItem (countryRS.Fields("countryName"))*
*countryRS.MoveNext*
*Next n*
I'm having a problem that occurs AFTER the code to populate the country combobox runs. The values are there as I can run Debug.Print(countryCombo.Value) and it prints out the name of the selected country, but I can't see the values in the combobox at all. They're invisible, and as far as I know there is no visiblity property for specific items, unless I'm completely mistaken.
comboBoxError.png http://img110.imageshack.us/my.php?image=comboboxerror.png
I think you should probably use Access's GUI tools to do what you're looking for. In design mode, click on the field you are trying to populate, then click the "lookup" tab. You can then specify a table to populate the field with and your forms should automaticly update as well.
I've also seen what you describe here - as far as I can tell, it's a bug within Access (I was using 2007) that only occurs when you programatically mess with the contents of a combo box. It does not happen every time. The issue corrects itself if you highlight the text that is in the combo box.
I am experiencing a similar issue with Access 2003. Based on the selection of one combo box, the row source of a listbox is set to an SQL string Basically a SELECT DISTINCT [MyField_Selected] FROM MyTable. For some fields the values are visible in the list box and others it is not. The values are there however as I can access them via code. To make it more interesting it works fine in Access 2007.
Just found the resolution on another forum. Check the format property of the field(s) in question on the table. In my case, when Access 2007 created the table, it put an # format in there. I removed that and all works great!