TableLayoutSettings.SetCellPosition Method (Object, TableLayoutPanelCellPosition)


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Sets the TableLayoutPanelCellPosition that represents the row and the column of the cell.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public void SetCellPosition(
	object control,
	TableLayoutPanelCellPosition cellPosition


Type: System.Object

A control contained within a cell.

Type: System.Windows.Forms.TableLayoutPanelCellPosition

A TableLayoutPanelCellPosition that represents the cell position.

Exception Condition

control is null.

The following example shows how to use a TableLayoutSettings object to set a cell position in a TableLayoutPanel control. For a full code listing, see How to: Implement a Custom ToolStripRenderer.

// The following class implements a sliding-tile puzzle.
// The GridStrip control is a custom ToolStrip that arranges
// its ToolStripButton controls in a grid layout. There is 
// one empty cell, into which the user can slide an adjacent
// tile with a drag-and-drop operation. Tiles that are eligible 
// for moving are highlighted.
public class GridStrip : ToolStrip
    // The button that is the drag source.
    private ToolStripButton dragButton = null;

    // Settings for the ToolStrip control's TableLayoutPanel.
    // This provides access to the cell position of each
    // ToolStripButton.
    private TableLayoutSettings tableSettings = null;

    // The empty cell. ToolStripButton controls that are
    // adjacent to this button can be moved to this button's
    // cell position.
    private ToolStripButton emptyCellButton = null;

    // The dimensions of each tile. A tile is represented
    // by a ToolStripButton controls.
    private Size tileSize = new Size(128, 128);

    // The number of rows in the GridStrip control.
    private readonly int rows = 5;

    // The number of columns in the GridStrip control.
    private readonly int columns = 5;

    // The one-time initialzation behavior is enforced
    // with this field. For more information, see the 
    // OnPaint method.
    private bool firstTime = false;

    // This is a required by the Windows Forms designer.
    private System.ComponentModel.IContainer components;

    // The default constructor.  
    public GridStrip()


    // This property exposes the empty cell to the 
    // GridStripRenderer class.
    internal ToolStripButton EmptyCell
            return this.emptyCellButton;

    // This utility method initializes the TableLayoutPanel 
    // which contains the ToolStripButton controls.
    private void InitializeTableLayoutSettings()
        // Specify the numbers of rows and columns in the GridStrip control.
        this.tableSettings = base.LayoutSettings as TableLayoutSettings;
        this.tableSettings.ColumnCount = this.rows;
        this.tableSettings.RowCount = this.columns;

        // Create a dummy bitmap with the dimensions of each tile.
        // The GridStrip control sizes itself based on these dimensions.
        Bitmap b = new Bitmap(tileSize.Width, tileSize.Height);

        // Populate the GridStrip control with ToolStripButton controls.
        for (int i = 0; i < this.tableSettings.ColumnCount; i++)
            for (int j = 0; j < this.tableSettings.RowCount; j++)
                // Create a new ToolStripButton control.
                ToolStripButton btn = new ToolStripButton();
                btn.DisplayStyle = ToolStripItemDisplayStyle.Image;
                btn.Image = b;
                btn.ImageAlign = ContentAlignment.MiddleCenter;
                btn.ImageScaling = ToolStripItemImageScaling.None;
                btn.Margin = Padding.Empty;
                btn.Padding = Padding.Empty;

                // Add the new ToolStripButton control to the GridStrip.

                // Set the cell position of the ToolStripButton control.
                TableLayoutPanelCellPosition cellPos = new TableLayoutPanelCellPosition(i, j);
                this.tableSettings.SetCellPosition(btn, cellPos);

                // If this is the ToolStripButton control at cell (0,0),
                // assign it as the empty cell button.
                if( i == 0 && j == 0 )
                    btn.Text = "Empty Cell";
                    btn.Image = b;
                    this.emptyCellButton = btn;

    // This method defines the Paint event behavior.
    // The GridStripRenderer requires that the GridStrip
    // be fully layed out when it is renders, so this
    // initialization code cannot be placed in the
    // GridStrip constructor. By the time the Paint
    // event is raised, the control layout has been 
    // completed, so the GridStripRenderer can paint
    // correctly. This one-time initialization is
    // implemented with the firstTime field.
    protected override void OnPaint(PaintEventArgs e)

        if (!this.firstTime)
            this.Renderer = new GridStripRenderer();

            // Comment this line to see the unscrambled image.
            this.firstTime = true;

    // This utility method changes the ToolStripButton control 
    // positions in the TableLayoutPanel. This scrambles the 
    // buttons to initialize the puzzle.
    private void ScrambleButtons()
        int i = 0;
        int lastElement = this.Items.Count - 1;

        while ( (i != lastElement ) &&
                (lastElement - i > 1) )
            TableLayoutPanelCellPosition pos1 = 

            TableLayoutPanelCellPosition pos2 = 



    // This method defines the MouseDown event behavior. 
    // If the user has clicked on a valid drag source, 
    // the drag operation starts.
    protected override void OnMouseDown(MouseEventArgs mea)

        ToolStripButton btn = this.GetItemAt(mea.Location) as ToolStripButton;

        if (btn != null)
            if (this.IsValidDragSource(btn))
                this.dragButton = btn;

    // This method defines the MouseMove event behavior. 
    protected override void OnMouseMove(MouseEventArgs mea)

        // Is a drag operation pending?
        if (this.dragButton != null)
            // A drag operation is pending. Call DoDragDrop to 
            // determine the disposition of the operation.
            DragDropEffects dropEffect = this.DoDragDrop(
                new DataObject(this.dragButton), 

    // This method defines the DragOver event behavior. 
    protected override void OnDragOver(DragEventArgs dea)

        // Get the ToolStripButton control 
        // at the given mouse position.
        Point p = new Point(dea.X, dea.Y);
        ToolStripButton item = this.GetItemAt(
            this.PointToClient(p)) as ToolStripButton;

        // If the ToolStripButton control is the empty cell,
        // indicate that the move operation is valid.
        if( item == this.emptyCellButton )
            // Set the drag operation to indicate a valid move.
            dea.Effect = DragDropEffects.Move;

    // This method defines the DragDrop event behavior. 
    protected override void OnDragDrop(DragEventArgs dea)

        // Did a valid move operation occur?
        if (dea.Effect == DragDropEffects.Move)
            // The move operation is valid. Adjust the state
            // of the GridStrip control's TableLayoutPanel,
            // by swapping the positions of the source button
            // and the empty cell button.

            // Get the cell of the control to move.
            TableLayoutPanelCellPosition sourcePos = 

            // Get the cell of the emptyCellButton.
            TableLayoutPanelCellPosition dropPos = 

            // Move the control to the empty cell.
            tableSettings.SetCellPosition(this.dragButton, dropPos);

            // Set the position of the empty cell to 
            // that of the previously occupied cell.
            tableSettings.SetCellPosition(this.emptyCellButton, sourcePos);

            // Reset the drag operation.
            this.dragButton = null;

    // This method defines the DragLeave event behavior. 
    // If the mouse leaves the client area of the GridStrip
    // control, the drag operation is canceled.
    protected override void OnDragLeave(EventArgs e)

        // Reset the drag operation.
        this.dragButton = null;

    // This method defines the ueryContinueDrag event behavior. 
    // If the mouse leaves the client area of the GridStrip
    // control, the drag operation is canceled.
    protected override void OnQueryContinueDrag(QueryContinueDragEventArgs qcdevent)

        // Get the current mouse position, in screen coordinates.
        Point mousePos = this.PointToClient(Control.MousePosition);

        // If the mouse position is outside the GridStrip control's
        // client area, cancel the drag operation. Be sure to
        // transform the mouse's screen coordinates to client coordinates. 
        if (!this.ClientRectangle.Contains(mousePos))
            qcdevent.Action = DragAction.Cancel;

    // This utility method determines if a button
    // is positioned relative to the empty cell 
    // such that it can be dragged into the empty cell.
    private bool IsValidDragSource(ToolStripButton b)
        TableLayoutPanelCellPosition sourcePos = 

        TableLayoutPanelCellPosition emptyPos = 

        return (IsValidDragSource(sourcePos, emptyPos));

    // This utility method determines if a cell position
    // is adjacent to the empty cell.
    internal static bool IsValidDragSource(
        TableLayoutPanelCellPosition sourcePos, 
        TableLayoutPanelCellPosition emptyPos)
        bool returnValue = false;

        // A cell is considered to be a valid drag source if it
        // is adjacent to the empty cell. Cells that are positioned
        // on a diagonal are not valid.
        if (((sourcePos.Column == emptyPos.Column - 1) && (sourcePos.Row == emptyPos.Row)) ||
            ((sourcePos.Column == emptyPos.Column + 1) && (sourcePos.Row == emptyPos.Row)) ||
            ((sourcePos.Column == emptyPos.Column) && (sourcePos.Row == emptyPos.Row - 1)) ||
            ((sourcePos.Column == emptyPos.Column) && (sourcePos.Row == emptyPos.Row + 1)))
            returnValue = true;

        return returnValue;

.NET Framework
Available since 2.0
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