![]() ![]()
However, from what I can see, this would require the Presenter to know about controls on the Form (at least control names) as the Presenter would call for example: Public void SetError(string controlName, string errorMessage) One possible solution I have read about is to have a SetError method defined in the View and implemented by the Form which takes the control name and error message as arguments and sets the error for the specified control e.g. #VISUAL STUDIO USING ERRORPROVIDER HOW TO#One issue I can't seem to find a clean solution to is how to wire up a Presenter with a windows forms ErrorProvider control. #VISUAL STUDIO USING ERRORPROVIDER CODE#/ parent control that contains databound controlsįoreach (Control control in ctl.I have been looking through the Patterns in Action solution especially in terms of the MVP pattern as I would like to refactor an existing application to use MVP as a lot of logic is tied up in the code behind the Forms. / Recursively check all controls contained See corrected versionĭataBindings may be DataSet. Provider.SetError(control,"Required Field") ĭataBinding property could have DataSet value. String tablename = ĭataColumn colunm = table.Columns get the bound table - if we're bound to a dataview,ĭataTable table = ( as DataTable) ĭataView view = ( as DataView) ĭataSet ds = ( as DataSet) If (null = boundField || 0 = boundField.Length) continue (control is ComboBox & (control as ComboBox).SelectedIndex = -1)) If ((control is TextBox & control.Text = "") || if the current control contains additional controls, run recursivelyĬheckNewRecordRequiredControls(control, provider) Public virtual void CheckNewRecordRequiredControls(Control ctl, ErrorProvider provider) ![]() If all you want to do is make sure a value has been entered, then you could use a procedure similar to ' CheckNewRecordRequiredControls', and if the control has a value then clear the WarningProvider like this: I check to see if the control is valid and then I clear the WarningProvider. I have event handlers for the ' Leave' event of my controls. Once the WarningProvider has been set, you do need to manage clearing it when it's appropriate. WarningProvider.SetError(control, " Required Field") not set up to handle bindings to anything // other than DataView or DataTable continue ![]() If ( is DataView)īoundTable = (Įlse if ( is DataTable) get the bound table - if we're bound to a dataview, // we need to get the table from that // otherwise just get to the DataTable string boundTable = string.Empty get bound field name string boundField =Ĭ if the current control contains additional controls, run recursively if ( > 0) / /// parent control that contains databound controls private void CheckNewRecordRequiredControls(Control ctl)įoreach (Control control in ctl.Controls) / within to see if they required a value / /// Recursively check all controls contained In your form/control, in the declarations section, add the following lines of code: Setting up the 'Warning Provider'įor the sake of this article, let's assume you have a strongly typed DataSet called AppDataSet, and that it contains a DataTable called Customer, with two required fields: Customer_Name and Customer_Type. Thirdly, if you don't want the default error icon for your 'warning', then add an ImageList control to your control/form, and add the 16x16 icon that you wish to use.įourthly, create a method called ' GetDataSet()' which will give you your DataSet object. If you're not using Strongly-Typed DataSets, the 'Warning Provider' will still work, as long as you have set the appropriate constraints. If you are not, please give yourself a little slap on the wrist, and then go read some articles about Strongly-Typed DataSets. #VISUAL STUDIO USING ERRORPROVIDER FULL#Hopefully anyone reading this article is making full use of Strongly-Typed DataSets. Secondly, we will be checking constraints on our DataSet. So, you need to be using bound controls for this to work. Prerequisitesįirst of all, I need to point out that we will be accessing the DataBinding information on our controls. Since the icon and message associated with the ErrorProvider can easily be changed, I figured that would be a good way to create a 'Warning Provider'. Examples The following code example demonstrates using the ErrorProvider class to notify the user of a data entry error. Exceptions ArgumentNullException control is null. value String The error description string, or null or Empty to remove the error. It's not interfering with my Save method, but it's really. The control to set the error description string for. I erased all the code related to it and also de ErrorProvider component in Dashboard.cs Design. However, it keeps popping up every time I insert a new row in DB even after deleting. I have always liked using the ErrorProvider as an easy way to alert the user that something is wrong. I tried to erase an ErrorProvider (called ErrorProvider1) for the FirstName column after a quick test. One way to do that is to 'point out' required fields, when they're adding new records. I like providing a friendly user interface for users of the applications I work on. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |