The following sections describe how to use and create custom grid editors.

Using Custom Editors

The built-in editors provide a lot of flexibility and power, but in some cases you may want to use external controls as specialized editors. For example, you may want to use the C1NumericEdit control that provides a drop-down calculator for entering numbers, or an editor for selecting from multi-column lists, or a specialized control that you wrote to edit your business objects.

Any control that derives from the base Control class can be used as a basic grid editor. Controls that implement the IC1EmbeddedEditor interface can provide better integration with the grid and more advanced features. For details on the IC1EmbeddedEditor interface, see the Editor property.

To use a control as a custom editor, all you have to do is associate an instance of the control with a grid column using the Editor property. You can do this in code using the Editor property. After that, the control will be automatically used by the grid.

For example, to use a C1NumericEdit control as a grid editor, follow these steps:

1. Add a C1TrueDBGrid control and a C1NumericInput control to the form.
2. For the C1NumericInput control, set the BorderStyle property to None and the Visible property to False either in the Properties window or by adding the following code to the Form_Load event:

   C#	Copy Code
   // Set up the custom editor. this.c1NumericEdit1.BorderStyle = BorderStyle.None; this.c1NumericEdit1.Visible = false;

3. In the Form_Load event assign the custom editor to the grid column.

   C#	Copy Code
   private void Form_Load(object sender, EventArgs e) { // Assign the custom editor to the grid. this.c1TrueDBGrid1.Columns[0].Editor = this.c1NumericEdit1; }

Run the project and edit some values in the first column. Notice how the grid positions and initializes the C1NumericEdit control so you can edit cell values. When you are done editing a cell, click a different cell or press the TAB key to move to the next one. Notice how the new value is applied to the cell.

Creating Custom Editors

Any control that derives from the Control base class can be used as a grid editor. This is possible because the grid knows enough about the base class to access properties such as Text and Bounds, and events such as Leave and TextChanged. In many cases this level of support is adequate.

In some cases, however, you may want to use controls that do not follow the base class that closely. For example, a DateTimePicker control has a Value property that should be used to retrieve the edited value instead of Text. In these cases, you can implement one or more methods in the IC1EmbeddedEditor interface to override the default behavior. For example, all controls in the C1Input library support IC1EmbeddedEditor and therefore integrate closely with C1TrueDBGrid (and also C1FlexGrid).

The IC1EmbeddedEditor interface is fairly simple, and because the grid binds to it using late binding, you do not even have to implement all its members. Only implement the ones that make sense to your editor control.

The interface does provide enough flexibility to allow virtually any control to be used as a grid editor. You can even use UITypeEditor classes as grid editors. To do this, you need a wrapper class that:

1. Derives from Control (UITypeEditor does not).
2. Implements the IC1EmbeddedEditor interface.
3. Encapsulates the appropriate UITypeEditor.

Using the UITypeEditor wrapper class, you can use any UITypeEditors with the C1TrueDBGrid. .NET provides several UITypeEditors for editing colors, fonts, file names, and so on. You can also write your own UITypeEditors, in some cases that is easier than writing a control.