Multi-line string in a PropertyGrid

Question

Is there a built-in editor for a multi-line string in a PropertyGrid.

Answer 1

I found that System.Design.dll has System.ComponentModel.Design.MultilineStringEditor which can be used as follows:

public class Stuff
{
    [Editor(typeof(MultilineStringEditor), typeof(UITypeEditor))]
    public string MultiLineProperty { get; set; }
}

Answer 2

No, you will need to create what's called a modal UI type editor. You'll need to create a class that inherits from UITypeEditor. This is basically a form that gets shown when you click on the ellipsis button on the right side of the property you are editing.

The only drawback I found, was that I needed to decorate the specific string property with a specific attribute. It's been a while since I had to do that. I got this information from a book by Chris Sells called "Windows Forms Programming in C#"

There's a commercial propertygrid called Smart PropertyGrid.NET by VisualHint.

Answer 3

Yes. I don't quite remember how it is called, but look at the Items property editor for something like ComboBox

Edited: As of @fryguybob, ComboBox.Items uses the System.Windows.Forms.Design.ListControlStringCollectionEditor

Answer 4

We need to write our custom editor to get the multiline support in property grid.

Here is the customer text editor class implemented from UITypeEditor

public class MultiLineTextEditor : UITypeEditor
{
    private IWindowsFormsEditorService _editorService;

    public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context)
    {
        return UITypeEditorEditStyle.DropDown;
    }

    public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
    {
        _editorService = (IWindowsFormsEditorService)provider.GetService(typeof(IWindowsFormsEditorService));

        TextBox textEditorBox = new TextBox();
        textEditorBox.Multiline = true;
        textEditorBox.ScrollBars = ScrollBars.Vertical;
        textEditorBox.Width = 250;
        textEditorBox.Height = 150;
        textEditorBox.BorderStyle = BorderStyle.None;
        textEditorBox.AcceptsReturn = true;
        textEditorBox.Text = value as string;

        _editorService.DropDownControl(textEditorBox);

        return textEditorBox.Text;
    }
}

Write your custom property grid and apply this Editor attribute to the property

class CustomPropertyGrid
{
    private string multiLineStr = string.Empty;

    [Editor(typeof(MultiLineTextEditor), typeof(UITypeEditor))]
    public string MultiLineStr
    {
        get { return multiLineStr; }
        set { multiLineStr = value; }
    }
}

In main form assign this object

 propertyGrid1.SelectedObject = new CustomPropertyGrid();