Vb net datagridview validating
Adding Items into a Data Grid View Combo Box Column Control The previous section showed how to display a Combo Box control within a cell in the Data Grid View control. This event is fired when the user is done with the typing and leaves the cell: Private Sub Data Grid View1_Cell Validating( _ By Val sender As Object, _ By Val e As System. Cell Validating Dim combo Box Column As Data Grid View Combo Box Column = _ Data Grid View1. If the Combo Box control is bound to a data source, you will not be able to add new items into it during runtime. Next, service the Cell Validating event of the Data Grid View control. _ Data Grid View Cell Validating Event Args) _ Handles Data Grid View1. First, service the Cell Validating event, which is fired when the user has finished modifying the value of a cell and leaves the cell: Private Sub Data Grid View1_Cell Validating( _ By Val sender As Object, _ By Val e As System. In this case, you need to add a Combo Box to the cells in the desired column. The following code snippet adds a Combo Box control to the fifth column of the Data Grid View control: '---add columns to the Data Grid View control--- Data Grid View1. Add(combo Box Col) The latter approach is more flexible as it allows the user to add new items into the drop-down list during runtime (see the next section for details). If it is, the drop-down style of the Combo Box control is set to Drop Down so that the user can type into it. To validate that the data entered is of the correct type, you need to service two events. _ Data Grid View Cell Validating Event Args) _ Handles Data Grid View1. Drop Down End If End If End Sub Here, you essentially check to see if the cell being edited is the one containing the Combo Box. Therefore, it is important to perform validation so that the users enter the correct type of data. Before we validate data to grid cell, we need to cancel the Validate Cell event to prevent the users from exiting the cell until entering a valid editor value or cancelling the edit process.Meanwhile, we can use the Validate Row event in the same way to prevent the user from exiting the current row.
To validate data to grid cells and rows, we need to use the Validate Cell event, which will be raised by the Kettic Data Grid View when there are any changes to the current cell or when the grid cell loses input focus like. Figure 12shows that originally the Combo Box contains three items. Locking Rows/Columns You can prevent users from modifying a particular row by setting the Read Only property for that particular row to True: Note that while setting the Read Only property to True prevents the user from editing the values in the cell, this does not affect his ability to delete rows. For example, in the above example, you will check that the fourth column (column index 3—the Price field) contains only numeric values. Formatted Value) End If End If End Sub Here, you will perform the usual checks and then add the newly typed item into the Combo Box. Note that for subsequent rows (as well as the rows above it) the Combo Box control will now contain four items. Cancel = True End If End If End Sub In this event, you will perform the necessary validation. Very often, users will input data into the individual cells in the control. To ensure that the error message goes away when the correct data is entered, service the Cell End Edit event, as follows: Private Sub Data Grid View1_Cell End Edit( _ By Val sender As Object, _ By Val e As System. Cell End Edit '---clear the error message--- Data Grid View1. If you want, you can lock the entire Data Grid View control: Validating Users' Edit A common use of the Data Grid View control is for data entry. If not, an error message is displayed on the leftmost column of the Data Grid View control (set via the Error Text property). The error must be corrected before the user can switch to the other cells. Data Grid View Cell Event Args) _ Handles Data Grid View1.