I have a DataTable that I am creating and binding to a GridView. Currently the headers do not have any spaces and it makes it hard to read. I want to space them out but I'm having a minor issue.[code]I know that I can set the HeaderText in the columns declaration like below, but I won't know how any columns I am going to have. And would rather the columns be generated automatically. [code]
View 2 RepliesHow would i get a certain text inside a textbox to equal that text space to space or null to space?
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If Textbox1.Text.StartsWith(Textbox2.Text + " ") And Not String.IsNullOrEmpty(Textbox2.Text) Then
Textbox1.Text = Textbox1.Text.Remove(0, Textbox2.TextLength)
Textbox3.AppendText("a")
End If
Btw: after i finish this step my project will be finished!
How do I go about adding a ButtonColumn to a DataTable.
I am basically using a DataTable as the DataSource of a DataGrid and need to add a ButtonColumn to the DataTable so that when I DataBind it to the DataGrid it all works.
Although when I try
dt.Columns.Add(buttonColumn)
This is not allowed. It has to be a basic DataColumn.
Anyone have any ideas what would prevent my data from not be ing able to be bound to my data column? [code]My error says cant bind to column named SellingPrice? I have many other columns ALL binding the same way and other parts of my program recognize SellingPrice ?
View 9 RepliesI am using a picture box. I want to be able to use the Space or Enter key to change the image in it. For that, I try to use the keydown function as follow:
Private Sub ChestWindow_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown
Select Case e.KeyCode
Case Keys.NumPad1[code]....
is the function which changes the image. It works well when I press '1' on my numeric part of the keyboard as a test.The issue is that when I press Space or Enter, the form containing the picturebox closes. (I've already put the keyPreview property to True)
Is there a way to change when an expression in a datacolumn is evaluated?
I'm trying to make a simple total function which sums the values of a particular column in a data grid. Normally the expression is evaluated when I leave from the datagridview, but I wish it to be evaluated when the row is changed.
in my datatable I've a String.Byte[] column which contains the array of bytes of an image. So, when the datatable is binded to the datagrid, I can see the picture, if present, and the red cross if is not presente. So I can remove the red cross, by assign a value to the DefaultValue property of the datacolumn. But what default value I've to assign?? I tried with system.dbnull.value but the red cross is still present.
View 8 RepliesFirst of all - It`s my first post here so welcome I have a short question.I have an array with strings values, and a datacolumn with values of the same data type. The question is - what is the most efficient method to find values which are in the array, but aren`t in the datacolumn?
View 18 RepliesThis is the code I have:
Sub Main()
Dim dts As New DataSet
Dim da As New SqlDataAdapter
Dim SolTabla As New DataTable
[code]....
For example, I want to access the second cell value in "Columna". How can I do this with no using a Datagrid?
I have a dataset with a number of data columns, due to sizing issues I've updated a number of the varchar columns from say VARCHAR(20) to VARCHAR(50).I'd like the DataTable to automatically grab the new column information, is this possible? I'd rather not go through each column in the table and update the length.
View 1 Repliesi read an article about datacolumn.expression property here [URL]. this is really great. but i was just wondering, for my case i want to use my custom function to use in the expression. basically, on my datatable i added an unbound column AGE. when i display records, i just want the age textbox to be populated with the computation of the person's age based on birthdate.
View 7 RepliesPrevent an empty column in Excel to be loaded into a dataset column?
View 3 Replieshow to prevent an empty column in Excel to be loaded into a dataset column?
View 10 RepliesI defined a DateTime datacolumn in a datatable dt as [code]]....
View 5 RepliesI'm adding a DateTime DataColumn to a DataTable like this:
Dim colDate As DataColumn = New DataColumn("Date")
colDate.DataType = System.Type.GetType("System.DateTime")
dt.Columns.Add(colDate)
Then when I try to add it to my datatable, if the value is Nothing I get an error saying string was not recognized as a valid DateTime. I'm having trouble getting this to work.
Can anyone demonstrate with an example how to shift the position of a datacolumn in a specific position after it is added at the end of a datatable.For example lets say I have a datatable with 9 columns and 5 rows. Now I added a 10th column. However I need this new column as the 5th column which requires shifting. How do I perform this shifting?
View 3 RepliesI'm using MySQL to store some numbers. One of the columns in the database is defined as unique, but it does allow multiple NULL-values. That is exactly how I want it.ut when I'm trying to load the data into my strongly typed DataSet, I get a error saying that a constraint fails... I do understand why that happens (several rows with NULL-values in a unique column), but is it a way to keep a DataColumn in vb.net unique, but still allow several rows with NULL-values like in MySQL?
View 2 Repliesdatacolumn expression subtracting dates and taking to datagridview
View 1 RepliesI am trying to build a filter string for my DataView, but I have run into a problem. My underlying DataTable contains values that are formatted when displayed in my DataGridView.For example, if the DataColumn contains 1.52 and the DataGridViewColumn.DefaultCellStyle.Format = "n0" then 2 is displayed.So the user sees 2, then sets the DataView.RowFilter = "DataColumn = 2", and no DataRows are returned. Is there a way to format the DataColumn in the RowFilter string? For example, DataView.RowFilter = "FORMAT(DataColumn, "n0") IN (2, 4)". This filter string should return 3 rows. If not, can LINQ do this?
View 5 RepliesI am currently working with a datatable and I want to be able to show richtext in a column of the table. First question can this be done? I can force the column to be Type Of richtext box. However, when I try to view/display the table, I get something like..."System.Windows.Forms.RichTextbox, Text: Text That I have added" in the column.
Is there a way that I can get it to show the rich text in a cell of a datacolumn of a datatable?
I have a datatable which loads data from an Excel Spreadsheet. One of the columns in the Excel SpreadSheet was of type "Date/Time" in which date values are stored. Now I appended the datatable with three new rows and I wanted to store string values in these rows using the code below. However due to the fact that one of the columns are date/time type, an error is generated as date/time column does not accept string value. I have two questions
a. Is it possible to store string value in date/time DataColumn?
b. Is there a remedy to this situation? [code]
I have a DataColumn and call the MaxLength Property on it to get the length of data that can go into a field ... but it always returns -1 (yes even on a string field).
View 8 RepliesI have a DataTable with two DateTime columns: "start_time" and "end_time".Now, I want to add a third column that calculates the difference between the two DateTimes. But I can't seem to figure out how. I've tried to set the .Expression-value to "start_time - end_time", but it says that "-"-operator is not allowed on DateTime.
View 4 RepliesI have added a column to a Datatable called CallsPerDay which is there to tell me how many telephone calls have been made on a particular day or days.Is there a datacolumn.expression which will allow me to Filter on the day, count the rows and then populate this added column with the result.
View 1 RepliesI am trying to write following expression on a datacolumn. But it results in error:Replicate('*', nLevel) + NameWhere: Replicate() is a user defined function (in a module). nLevel and Name are two other columns in same data table.
View 3 RepliesI'm trying to assign some parameters for a stored procedure with some values that are stored in a data table. in the code, I can set the parameter values to the data table, and give a column header or index without issue, but when it tries to execute at runtime it bombs out.the error I get is a variation on "Failed to Convert Parameter Value from a DataColumn to a String" depending on exactly how I try to assign the value.the data types are all correct elsewhere in the code.
my code for this bit is
Try
ConnectionAttempt.Open()
Try
With NewYearCommand_Dates
[code]....
other things I've tried to get this to work are all variations on the .Value=dates bit, such as
.Value=dates(0) (so using column index)
.Value=dates.columns(0) (again using column index)
I've also tried declaring variables, and setting their values to the values in the columns, but the code returns an error saying that "Value of type 'System.Data.DataColumn' cannot be converted to string".I should point out that i'm doing this for 3 tables at once in this sub, 2 of them will only have a single row of data, but the third has an indeterminate number of rows.I'm afraid I don't know what else to do. I'm lead to believe by my mate and my lecturer that this should work, and of course it will work, but the evidence says otherwise.
i have a requirement that my <xsd:string> should allow space.it should not validate the space. but naturally it will not allow space. but i need it should allow space.
View 1 Repliesi want to add a space every 5 characters of a string. My code below able to do that only for those character in the beginning. For those at the back, it never insert the spacing.
[Code]...
I would like to get the width of some text drawn by GDI+ in an Integer so that I can adjust the position of a cursor.
I used:
"lCursor = g.MeasureString(vInputText, Font)"
In which 'lCursor' is the offset for the original location of the cursor. But apparently the output of MeasureString is not integer and can't even parse it to integer.
i tried to create a namespace but its giving error .Warning 5 Namespace or type specified in the Imports 'one' doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases.i opened a new class file ie class1.vb in that i cretaed namespace.[code...]
View 7 Replies