ComponentEditor Class
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Provides the base class for a custom component editor.
public ref class ComponentEditor abstract
public abstract class ComponentEditor
type ComponentEditor = class
Public MustInherit Class ComponentEditor
- Inheritance
-
ComponentEditor
- Derived
The following code example demonstrates an example ComponentEditor implementation.
using System;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Drawing;
using System.Windows.Forms;
// This example demonstrates how to implement a component editor that hosts
// component pages and associate it with a component. This example also
// demonstrates how to implement a component page that provides a panel-based
// control system and Help keyword support.
namespace ComponentEditorExample
{
// The ExampleComponentEditor displays two ExampleComponentEditorPage pages.
public class ExampleComponentEditor : System.Windows.Forms.Design.WindowsFormsComponentEditor
{
// This method override returns an type array containing the type of
// each component editor page to display.
protected override Type[] GetComponentEditorPages()
{
return new Type[] { typeof(ExampleComponentEditorPage),
typeof(ExampleComponentEditorPage) };
}
// This method override returns the index of the page to display when the
// component editor is first displayed.
protected override int GetInitialComponentEditorPageIndex()
{
return 1;
}
}
// This example component editor page type provides an example
// ComponentEditorPage implementation.
internal class ExampleComponentEditorPage : System.Windows.Forms.Design.ComponentEditorPage
{
Label l1;
Button b1;
PropertyGrid pg1;
public ExampleComponentEditorPage()
{
// Initialize the page, which inherits from Panel, and its controls.
this.Size = new Size(400, 250);
this.Icon = new Icon("myicon.ico");
this.Text = "Example Page";
b1 = new Button();
b1.Size = new Size(200, 20);
b1.Location = new Point(200, 0);
b1.Text = "Set a random background color";
b1.Click += new EventHandler(this.randomBackColor);
this.Controls.Add(b1);
l1 = new Label();
l1.Size = new Size(190, 20);
l1.Location = new Point(4, 2);
l1.Text = "Example Component Editor Page";
this.Controls.Add(l1);
pg1 = new PropertyGrid();
pg1.Size = new Size(400, 280);
pg1.Location = new Point(0, 30);
this.Controls.Add(pg1);
}
// This method indicates that the Help button should be enabled for this
// component editor page.
public override bool SupportsHelp()
{
return true;
}
// This method is called when the Help button for this component editor page is pressed.
// This implementation uses the IHelpService to show the Help topic for a sample keyword.
public override void ShowHelp()
{
// The GetSelectedComponent method of a ComponentEditorPage retrieves the
// IComponent associated with the WindowsFormsComponentEditor.
IComponent selectedComponent = this.GetSelectedComponent();
// Retrieve the Site of the component, and return if null.
ISite componentSite = selectedComponent.Site;
if (componentSite == null)
return;
// Acquire the IHelpService to display a help topic using a indexed keyword lookup.
IHelpService helpService = (IHelpService)componentSite.GetService(typeof(IHelpService));
if (helpService != null)
helpService.ShowHelpFromKeyword("System.Windows.Forms.ComboBox");
}
// The LoadComponent method is raised when the ComponentEditorPage is displayed.
protected override void LoadComponent()
{
this.pg1.SelectedObject = this.Component;
}
// The SaveComponent method is raised when the WindowsFormsComponentEditor is closing
// or the current ComponentEditorPage is closing.
protected override void SaveComponent()
{
}
// If the associated component is a Control, this method sets the BackColor to a random color.
// This method is invoked by the button on this ComponentEditorPage.
private void randomBackColor(object sender, EventArgs e)
{
if (typeof(System.Windows.Forms.Control).IsAssignableFrom(this.Component.GetType()))
{
// Sets the background color of the Control associated with the
// WindowsFormsComponentEditor to a random color.
Random rnd = new Random();
((System.Windows.Forms.Control)this.Component).BackColor =
Color.FromArgb(rnd.Next(255), rnd.Next(255), rnd.Next(255));
pg1.Refresh();
}
}
}
// This example control is associated with the ExampleComponentEditor
// through the following EditorAttribute.
[EditorAttribute(typeof(ExampleComponentEditor), typeof(ComponentEditor))]
public class ExampleUserControl : System.Windows.Forms.UserControl
{
}
}
A component editor is used to edit a component as a whole and can be used to implement a user interface similar to that of the property pages. You associate a component editor with a component by using the EditorAttribute attribute.
When you inherit from this class, you must override the EditComponent(Object) method.
Component |
Initializes a new instance of the ComponentEditor class. |
Edit |
Edits the component and returns a value indicating whether the component was modified based upon a given context. |
Edit |
Edits the component and returns a value indicating whether the component was modified. |
Equals(Object) |
Determines whether the specified object is equal to the current object. (Inherited from Object) |
Get |
Serves as the default hash function. (Inherited from Object) |
Get |
Gets the Type of the current instance. (Inherited from Object) |
Memberwise |
Creates a shallow copy of the current Object. (Inherited from Object) |
To |
Returns a string that represents the current object. (Inherited from Object) |
Product | Versions |
---|---|
.NET | Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 2.0, 2.1 |
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