Class

RadMultiColumnComboBox

Initializes a new instance of the RadMultiColumnComboBox class with default settings. Sets up basic control properties including auto-sizing, tab behavior, and selection capabilities.

Declaration

public RadMultiColumnComboBox()

Gets or sets the automatic completion mode for the text entry portion of the combo box. This property is not applicable for RadMultiColumnComboBox and should not be used.

Declaration

[Browsable(false)]
public AutoCompleteMode AutoCompleteMode { get; set; }

Property Value

Gets or sets a value indicating whether automatic filtering is enabled based on user input. When enabled, the dropdown list is filtered as the user types in the text box.

Declaration

public bool AutoFilter { get; set; }

Property Value

Gets or sets the delay in milliseconds between the last key press and the start of the filtering operation. This property helps optimize performance by preventing excessive filtering during rapid typing.

Declaration

public int AutoFilterDelay { get; set; }

Property Value

Gets or sets a value indicating whether the control is automatically resized to display its entire contents. This property controls the auto-sizing behavior of the entire combo box control.

Declaration

[Browsable(true)]
public override bool AutoSize { get; set; }

Property Value

Overrides RadControl.AutoSize

Gets or sets the mode for automatically sizing columns in the dropdown portion of the control. Determines whether columns are sized based on visible cells, all cells, or other criteria.

Declaration

public virtual BestFitColumnMode AutoSizeDropDownColumnMode { get; set; }

Property Value

Gets or sets a value indicating whether the dropdown height automatically adjusts when filtering is applied. When enabled, the dropdown shrinks or expands based on the number of filtered results.

Declaration

public bool AutoSizeDropDownHeight { get; set; }

Property Value

Gets or sets a value indicating whether the dropdown automatically resizes to best fit all columns. The DropDownWidth property must be set to its default value (-1) for this setting to work properly.

Declaration

public bool AutoSizeDropDownToBestFit { get; set; }

Property Value

Gets or sets a value indicating whether the text is automatically cleared when it does not match any value in the DisplayMember column. When enabled, invalid text entries are automatically removed during validation.

Declaration

[Browsable(true)]
public bool ClearTextOnValidation { get; set; }

Property Value

Gets the collection of columns displayed in the dropdown grid. Use this collection to define, configure, and manage the columns that appear in the dropdown interface.

Declaration

public GridViewColumnCollection Columns { get; }

Property Value

Gets or sets the data source for the combo box. The data source provides the items that are displayed in the dropdown grid.

Declaration

public object DataSource { get; set; }

Property Value

Gets or sets a value indicating whether double-clicking in the text edit area rotates through available items. When enabled, double-clicking cycles through the selectable values in the dropdown.

Declaration

[Browsable(true)]
public bool DblClickRotate { get; set; }

Property Value

Gets the default size of the control when no explicit size is specified. The default size provides a reasonable starting point for the control's dimensions.

Declaration

protected override Size DefaultSize { get; }

Property Value

Overrides Control.DefaultSize

Gets or sets the name of the data source member used to supply the display text for items in the combo box. This property determines which field from the data source is shown to the user.

Declaration

[TypeConverter("System.Windows.Forms.Design.DataMemberFieldConverter, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")]
public string DisplayMember { get; set; }

Property Value

Gets or sets the maximum size allowed for the dropdown portion of the combo box. This prevents the dropdown from becoming too large and overwhelming the interface.

Declaration

public Size DropDownMaxSize { get; set; }

Property Value

Gets or sets the minimum size allowed for the dropdown portion of the combo box. This prevents the dropdown from becoming too small to be usable.

Declaration

public Size DropDownMinSize { get; set; }

Property Value

Gets or sets the sizing mode for the dropdown portion of the control. The mode can be horizontal, vertical, or a combination that determines how the dropdown is resized.

Declaration

[Browsable(true)]
public SizingMode DropDownSizingMode { get; set; }

Property Value

Gets or sets the dropdown style of the combo box, which determines the appearance and editing behavior. This controls whether the text portion is editable and how the dropdown is presented.

Declaration

[Browsable(true)]
public RadDropDownStyle DropDownStyle { get; set; }

Property Value

Gets the RadGridView control hosted in the popup form that provides the multi-column interface. This grid displays the data and handles user selection within the dropdown.

Declaration

public virtual RadGridView EditorControl { get; }

Property Value

Gets the hosted RadMultiColumnComboBoxElement that provides the core functionality of the combo box. This element contains all the logic for dropdown management, data binding, and user interaction.

Declaration

[Browsable(false)]
public RadMultiColumnComboBoxElement MultiColumnComboBoxElement { get; }

Property Value

Gets the popup form that contains the multi-column grid interface. This form is displayed when the dropdown is opened and contains the RadGridView for data selection.

Declaration

protected MultiColumnComboPopupForm MultiColumnPopupForm { get; }

Property Value

Gets or sets the placeholder text that is displayed when the Text property contains an empty string or is null. This provides a visual hint to users about the expected input or purpose of the control.

Declaration

[Browsable(true)]
[Bindable(true)]
public string NullText { get; set; }

Property Value

Gets or sets a value indicating whether the control is in read-only mode. When read-only, users can view and select items but cannot edit the text portion.

Declaration

[Browsable(true)]
public bool ReadOnly { get; set; }

Property Value

Gets or sets a value indicating whether the user can scroll through items using the mouse wheel when the popup is closed. This enables convenient item navigation without opening the dropdown.

Declaration

public bool ScrollOnMouseWheel { get; set; }

Property Value

Gets or sets the index of the currently selected item in the combo box. A value of -1 indicates that no item is selected.

Declaration

[Browsable(false)]
public int SelectedIndex { get; set; }

Property Value

Gets or sets the currently selected item in the combo box. This represents the entire data object corresponding to the selected row.

Declaration

[Browsable(false)]
[Bindable(true)]
public object SelectedItem { get; set; }

Property Value

Gets or sets the value of the currently selected item as determined by the ValueMember property. This property provides the underlying value associated with the selected item.

Declaration

[Browsable(false)]
[Bindable(true)]
public object SelectedValue { get; set; }

Property Value

Gets or sets a value indicating whether ToolTips are shown for the RadItem objects contained in the control. When enabled, tooltips are displayed for both the control and its dropdown grid items.

Declaration

public override bool ShowItemToolTips { get; set; }

Property Value

Overrides RadControl.ShowItemToolTips

Gets or sets the text displayed in the text box portion of the combo box. This text represents the current selection or user input and can be bound to data sources.

Declaration

public override string Text { get; set; }

Property Value

Overrides RadControl.Text

Gets or sets the name of the data source member used to supply the value for items in the combo box. This property determines which field from the data source provides the actual value for each item.

Declaration

[TypeConverter("System.Windows.Forms.Design.DataMemberFieldConverter, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")]
public string ValueMember { get; set; }

Property Value

Automatically adjusts the width of all columns based on the content of visible rows. This method resizes columns to optimally display their content without horizontal scrolling.

Declaration

public void BestFitColumns()

Automatically adjusts the width of all columns with options for dropdown sizing and row analysis. This overload provides more control over the best-fit operation.

Declaration

public void BestFitColumns(bool adjustComboBoxSize, bool bestFitAllRows)

Parameters

Determines whether the control defines a theme for the specified element. This method prevents theme duplication by indicating which elements have control-defined themes.

Declaration

public override bool ControlDefinesThemeForElement(RadElement element)

Parameters

Returns

Overrides RadControl.ControlDefinesThemeForElement(RadElement)

Creates the child element hierarchy for the combo box control. This method establishes the main combo box element and wires up all necessary event handlers.

Declaration

protected override void CreateChildItems(RadElement parent)

Parameters

Overrides RadControl.CreateChildItems(RadElement)

Creates and returns a new instance of the RadMultiColumnComboBoxElement that serves as the main element for this control. This method can be overridden to provide custom element implementations.

Declaration

protected virtual RadMultiColumnComboBoxElement CreateMultiColumnComboBoxElement()

Returns

Releases the unmanaged resources used by the RadMultiColumnComboBox and optionally releases the managed resources.

Declaration

protected override void Dispose(bool disposing)

Parameters

Overrides RadControl.Dispose(bool)

Completes the initialization of the combo box control that is used on a form or by another component. The initialization occurs at run time and finalizes the setup of the control.

Declaration

public override void EndInit()

Overrides RadControl.EndInit()

Determines whether the specified key is an input key that should be processed by the control. This method handles special keys like Up and Down arrows for dropdown-style controls.

Declaration

protected override bool IsInputKey(Keys keyData)

Parameters

Returns

Overrides RadControl.IsInputKey(Keys)

Raises the BindingContextChanged event and synchronizes the binding context with the editor control. This method ensures that data binding contexts are properly propagated to the dropdown grid.

Declaration

protected override void OnBindingContextChanged(EventArgs e)

Parameters

Overrides RadControl.OnBindingContextChanged(EventArgs)

Raises the CaseSensitiveChanged event. This method is called when the case sensitivity setting changes.

Declaration

protected virtual void OnCaseSensitiveChanged(EventArgs e)

Parameters

Raises the DataBindingComplete event when the underlying grid completes its data binding process. This method is called after the grid has been populated with data from the data source.

Declaration

protected virtual void OnDataBindingComplete(GridViewBindingCompleteEventArgs e)

Parameters

Raises the DropDownClosed event. This method is called after the dropdown window has closed.

Declaration

protected virtual void OnDropDownClosed(RadPopupClosedEventArgs e)

Parameters

Raises the DropDownClosing event. This method is called when the dropdown window is about to close and allows cancellation.

Declaration

protected virtual void OnDropDownClosing(RadPopupClosingEventArgs e)

Parameters

Raises the DropDownOpened event. This method is called after the dropdown window has opened.

Declaration

protected virtual void OnDropDownOpened(EventArgs e)

Parameters

Raises the DropDownOpening event. This method is called when the dropdown window is about to open and allows cancellation.

Declaration

protected virtual void OnDropDownOpening(CancelEventArgs e)

Parameters

Raises the DropDownStyleChanged event. This method is called when the dropdown style changes.

Declaration

protected virtual void OnDropDownStyleChanged(EventArgs e)

Parameters

Raises the Enter event and transfers focus to the text box element. This method ensures proper focus handling when the control receives focus.

Declaration

protected override void OnEnter(EventArgs e)

Parameters

Overrides Control.OnEnter(EventArgs)

Raises the GotFocus event and selects all text in the text box. This method provides convenient text selection when the control gains focus.

Declaration

protected override void OnGotFocus(EventArgs e)

Parameters

Overrides RadControl.OnGotFocus(EventArgs)

Raises the Leave event and closes the popup if it is open. This method handles cleanup when the control loses focus.

Declaration

protected override void OnLeave(EventArgs e)

Parameters

Overrides Control.OnLeave(EventArgs)

Raises the LostFocus event and handles selection state when focus is lost. This method processes the current selection and clears text selection if appropriate.

Declaration

protected override void OnLostFocus(EventArgs e)

Parameters

Overrides RadControl.OnLostFocus(EventArgs)

Raises the ParentChanged event and closes the popup when the parent changes. This method ensures proper cleanup when the control is moved to a different parent.

Declaration

protected override void OnParentChanged(EventArgs e)

Parameters

Overrides RadEditorControl.OnParentChanged(EventArgs)

Raises the ParentVisibleChanged event and closes the popup when the parent's visibility changes. This method handles popup closure when the parent container becomes invisible.

Declaration

protected override void OnParentVisibleChanged(EventArgs e)

Parameters

Overrides Control.OnParentVisibleChanged(EventArgs)

Raises the SelectedIndexChanged event. This method is called when the selected index changes.

Declaration

protected virtual void OnSelectedIndexChanged(EventArgs e)

Parameters

Raises the SelectedValueChanged event. This method is called when the selected value changes.

Declaration

protected virtual void OnSelectedValueChanged(EventArgs e)

Parameters

Raises the SortedChanged event. This method is called when the sorting configuration changes.

Declaration

protected virtual void OnSortedChanged(EventArgs e)

Parameters

Raises the VisibleChanged event and closes the popup if the control becomes invisible. This method ensures the popup is closed when the control is hidden.

Declaration

protected override void OnVisibleChanged(EventArgs e)

Parameters

Overrides RadControl.OnVisibleChanged(EventArgs)

Processes auto-size mode changes and adjusts the element's stretch behavior accordingly. When auto-sizing is enabled, the control stretches horizontally but not vertically.

Declaration

protected override void ProcessAutoSizeChanged(bool value)

Parameters

Overrides RadControl.ProcessAutoSizeChanged(bool)

Processes command keys and handles special key combinations. This method intercepts Tab key presses to properly set the current row in the dropdown grid.

Declaration

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)

Parameters

Returns

Overrides Control.ProcessCmdKey(ref Message, Keys)

Resets theme value overrides for the BackColor property and reapplies the default theme. This method clears custom background color overrides and restores theme-based coloring.

Declaration

protected override void ResetBackColorThemeOverrides()

Overrides RadControl.ResetBackColorThemeOverrides()

Resets theme value overrides for the ForeColor property and reapplies the default theme. This method clears custom foreground color overrides and restores theme-based coloring.

Declaration

protected override void ResetForeColorThemeOverrides()

Overrides RadControl.ResetForeColorThemeOverrides()

Sets theme value overrides for the BackColor property across all visual states. This method ensures consistent background color theming for the combo box and its text element.

Declaration

protected override void SetBackColorThemeOverrides()

Overrides RadControl.SetBackColorThemeOverrides()

Sets the binding context of the editor control to match the combo box's binding context. This ensures consistent data binding behavior between the control and its dropdown grid.

Declaration

protected virtual void SetEditorControlBindingContext()

Sets theme value overrides for the ForeColor property across all visual states. This method ensures consistent foreground color theming for the combo box element.

Declaration

protected override void SetForeColorThemeOverrides()

Overrides RadControl.SetForeColorThemeOverrides()

Unwires the data binding event handler from the editor control if it is available. This is called during cleanup to ensure proper event handler removal.

Declaration

protected virtual void UnwireEditorControlDataBindingEvent()

Unwires all event handlers that were previously attached to the combo box element. This method is called during disposal to prevent memory leaks.

Declaration

protected virtual void UnwireEvents()

Wires the data binding event handler for the editor control if it is available. This enables handling of data binding completion events from the underlying grid.

Declaration

protected virtual void WireEditorControlDataBindingEvent()

Wires all necessary event handlers between the combo box element and the control. This includes handlers for text changes, selection changes, popup events, and keyboard input.

Declaration

protected virtual void WireEvents()

Occurs when the CaseSensitive property value changes. This event is raised when the case sensitivity property value changes.

Declaration

[Browsable(true)]
public event EventHandler CaseSensitiveChanged

Event Value

Occurs when the data binding process for the underlying grid control finishes. This event is useful for performing actions after the grid has been populated with data.

Declaration

public event GridViewBindingCompleteEventHandler DataBindingComplete

Event Value

Occurs after the dropdown window has closed and is no longer visible. This event provides information about how and why the dropdown was closed.

Declaration

[Browsable(true)]
public event RadPopupClosedEventHandler DropDownClosed

Event Value

Occurs when the dropdown window is about to close. This event can be used to cancel the closing operation or perform cleanup actions.

Declaration

[Browsable(true)]
public event RadPopupClosingEventHandler DropDownClosing

Event Value

Occurs after the dropdown window has opened and is visible to the user. This event is useful for performing actions once the dropdown interface is available.

Declaration

[Browsable(true)]
public event EventHandler DropDownOpened

Event Value

Occurs when the dropdown window is about to open. This event can be used to cancel the opening operation or prepare the dropdown content.

Declaration

[Browsable(true)]
public event RadPopupOpeningEventHandler DropDownOpening

Event Value

Occurs when the DropDownStyle property value changes. This event is raised when the dropdown style is modified.

Declaration

[Browsable(true)]
public event EventHandler DropDownStyleChanged

Event Value

Occurs when the ReadOnly property value changes. This event is raised when the read-only state of the control is modified.

Declaration

public event EventHandler ReadOnlyChanged

Event Value

Occurs when the SelectedIndex property value changes. This event is raised whenever a different item is selected in the combo box.

Declaration

[Browsable(true)]
public event EventHandler SelectedIndexChanged

Event Value

Occurs when the SelectedValue property value changes. This event is raised whenever the value of the selected item changes.

Declaration

[Browsable(true)]
public event EventHandler SelectedValueChanged

Event Value

Occurs when the sorting configuration of the dropdown grid changes. This event is raised when columns are sorted or unsorted.

Declaration

[Browsable(true)]
public event EventHandler SortedChanged

Event Value