GridViewCheckedDropDownListColumn

[Paul]

I am trying to create a GridViewCheckedDropDownListColumn. I have some of it working.

It is creating the column and the drop-down is displaying as it should. However, the main cell does not show the checked items after the drop-down is no longer displayed. Nor does it remember which items had previously been checked when the drop-down is displayed a second time.

 

I wasn't able to attach my project, so here is the important code:

public class Foo
{
    public int Id { get; set; }

    public string Value { get; set; }

    public bool IsSelected { get; set; }
}

public class Boo : Foo
{
    public List<Foo> Foos { get; set; }

    public Boo()
    {
        this.Foos = new List<Foo>();
    }
}

 

public class RadCheckedDropDownListEditorElement : RadCheckedDropDownListElement
{
    ...
}

public class RadCheckedDropDownListEditor : BaseGridEditor
{
    public string ValueMember { get; set; }

    public string DisplayMember { get; set; }

    public string CheckedMember { get; set; }

    public override object Value
    {
        get
        {
            var listEditorElement = (RadCheckedDropDownListElement) this.EditorElement;
            return listEditorElement.DataSource;
        }
        set
        {
            var listEditorElement = (RadCheckedDropDownListElement) this.EditorElement;
            listEditorElement.ValueMember = this.ValueMember;
            listEditorElement.DisplayMember = this.DisplayMember;
            listEditorElement.CheckedMember = this.CheckedMember;
            listEditorElement.DataSource = value;
        }
    }

    [AttributeProvider(typeof(IListSource))]
    [RadDescription("DataSource", typeof(RadListElement))]
    [Category("Data")]
    [RadDefaultValue("DataSource", typeof(RadListElement))]
    public object DataSource
    {
        get
        {
            var listEditorElement = (RadCheckedDropDownListElement)this.EditorElement;
            return listEditorElement.DataSource;
        }
        set
        {
            var listEditorElement = (RadCheckedDropDownListElement)this.EditorElement;
            listEditorElement.DataSource = value;
        }
    }

    protected override RadElement CreateEditorElement()
    {
        return new RadCheckedDropDownListEditorElement();
    }
}

public class GridViewCheckedDropDownListColumn : GridViewComboBoxColumn
{
    private RadCheckedDropDownListEditor _editor;
    private string _checkedMember;

    [Browsable(true)]
    [Editor("System.Windows.Forms.Design.DataMemberFieldEditor, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", typeof(UITypeEditor))]
    [Category("Data")]
    [DefaultValue(null)]
    [Description("Gets or sets a string that specifies the property or database column from which to get values that correspond to the items in the RadDropDownListEditor.")]
    [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
    public string CheckedMember
    {
        get
        {
            return this._checkedMember;
        }
        set
        {
            if (this._checkedMember == value) return;
            this._checkedMember = value;
            this.DispatchEvent(KnownEvents.ColumnDataSourceInitializing, GridEventType.UI, GridEventDispatchMode.Send, (object)null, (object[])null);
        }
    }

    public GridViewCheckedDropDownListColumn()
    {
    }

    public GridViewCheckedDropDownListColumn(string fieldName) : base(fieldName)
    {
    }

    public GridViewCheckedDropDownListColumn(string uniqueName, string fieldName) : base(uniqueName, fieldName)
    {
    }

    public override Type GetDefaultEditorType()
    {
        return typeof(RadCheckedDropDownListEditor);
    }

    public override IInputEditor GetDefaultEditor()
    {
        return new RadCheckedDropDownListEditor();
    }

    public override void InitializeEditor(IInputEditor editor)
    {
        var dropDownListEditor = (RadCheckedDropDownListEditor) editor;

        if (dropDownListEditor == null) return;

        dropDownListEditor.ValueMember = this.ValueMember;
        dropDownListEditor.DisplayMember = this.DisplayMember;
        dropDownListEditor.CheckedMember = this.CheckedMember;
        dropDownListEditor.DataSource = this.DataSource;
    }

    public virtual void RadGridView_EditorRequired(object sender, EditorRequiredEventArgs e)
    {
        if (e.EditorType == typeof(RadCheckedDropDownListEditor))
        {
            e.Editor = this._editor ?? (this._editor = new RadCheckedDropDownListEditor());
        }
    }
}

 

public partial class Form1 : Form
{
    private List<Boo> _boos;

    public Form1()
    {
        this.InitializeComponent();
        this.InitializeList();
        this.InitializeColumns();
        this.radGridView.DataSource = this._boos;
    }

    private void InitializeList()
    {
        this._boos = new List<Boo>();

        for (int i = 0; i < 10; i++)
        {
            Boo b = new Boo
            {
                Id = i,
                Value = $"Boo-{i}"
            };

            for (int j = 0; j < 10; j++)
            {
                Foo f = new Foo
                {
                    Id = j,
                    Value = $"Foo-{i}.{j}"
                };
                b.Foos.Add(f);
            }

            this._boos.Add(b);
        }
    }

    private void InitializeColumns()
    {
        var c1 = new GridViewTextBoxColumn(nameof(Boo.Id));
        var c2 = new GridViewTextBoxColumn(nameof(Boo.Value));
        var c3 = new GridViewCheckedDropDownListColumn(nameof(Boo.Foos))
        {
            ValueMember = nameof(Foo.Id),
            DisplayMember = nameof(Foo.Value),
            CheckedMember = nameof(Foo.IsSelected),
            Width = 500
        };

        this.radGridView.Columns.Add(c1);
        this.radGridView.Columns.Add(c2);
        this.radGridView.Columns.Add(c3);

        this.radGridView.EditorRequired += c3.RadGridView_EditorRequired;
    }
}

[Hristo]

Hi Paul,

Thank you for writing.

Please check the attached project for an example how this can be achieved. You would only need to create a custom editor as a descendant of RadCheckedDropDownListElement. You can also find the example in our documentation: http://www.telerik.com/help/winforms/dropdown-and-listcontrol-checked-dropdownlist-how-to-use-as-radgridview-editor.html. 

I am also sending you a short video showing the result on my end. In case you need additional information or the solution does not fit your scenario please let me know.

I hope this helps. Should you have further questions please do not hesitate to write back.

Regards,
Hristo Merdjanov
Telerik