How to create new components in Visual Studio 2010

问题:

Can you tell me how to create new visual component for .net 4.0 in Visual Studio 2010, i have a book about component creation in Russian Language (Pavel Agurov -Razrabotka Komponentov v MS Visual Studio 2005/2008), but methods in this book covers VS 2005 and 2008. And methods gives some errors in VS 2010.

EDIT: There is my code

public partial class exComboBox : ComboBox
{
    /*public exComboBox()
    {
        InitializeComponent();
    }*/
    private System.Collections.Specialized.StringCollection _itemValues = new System.Collections.Specialized.StringCollection();

    [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
    [Editor("System.Windows.Forms.Design.StringCollectionEditor,System.Editor","System.Drawing.Design.UITypeEditor,System.Drawing")]
    public System.Collections.Specialized.StringCollection ItemValues
    {
        get
        {
            return _itemValues;
        }
        set
        {
            _itemValues = value;
        }
    }
    public object SelectedItemValue
    {
        get
        {
            return _itemValues[SelectedIndex];
        }
    }
}

And when I try to add this component to new form and add values for ItemValues it says
Constructor on type 'System.String' not found.

回答1:

Right click your project, choose to add a new item. Go to the C# section and select User Control.

This will create a windows control that will appear at the top of the Toolbox when you use the forms designer. Just drag and drop it into your form like any other control.

If you wish to derive it from Combo Box, then just edit the class that is created and change it's base class from a UserControl to a combo box. You might also need to change your constructor top call three base class constructor rather than doing InitialiseComponent for itself.

If you want to use this control in many applications, then you can put the code into a Class Library project, which will make a .dll assembly that other projects can reference to gain access to the control.

回答2:

Create a Windows Application and then go to Add New Item menu by right clicking on Project in Solution Explorer and you can see there the Component AFAIR.

回答3:

Assuming you're talking about Winforms...

Deriving from existing controls is probably not something you'll want to do. Especially if you want to change their default behavior or replace their existing properties. Sooner or later you will be facing severe limitations. Believe me, I've been there.

If you want an easy way to repeat some kind of pattern for a ComboBox, I suggest you take a look at IExtenderProvider interface. You can implement it on a Component-derived class that you can drag on the design surface. In this component, you can declare properties that will be attached as extra properties to any comboboxes (or anything else, it's all up to you).

Since the component will know about whatever is attached to it, it will be able to declare event handlers over any attached control / component. For example, if you want your combobox to have items already present, you could handle it's Load event and add the items there.

To learn more about IExtenderProvider, go here.