How to Move Controls at RunTime in a flowLayoutPanel Control?

How to Move Controls at RunTime in a flowLayoutPanel Control?

• Andrej Burger

  Thanks a lot!

  It is exactly what I needed

  Deza

  
  

• tbthtbth

  Hi Deza,

  Here are the basic steps:

  1) Dragdrop requires handling specific type names. Since your FlowLayoutPanel is likely to have multiple types, the easiest way is to use a wrapper to reduce all types to one. This way you avoid having to use extensive if then constructions. Example:
  class MyWrapper
  {
      private Control control;
  
      public MyWrapper(Control control)
      {
          this.control = control;
      }

      public Control Control
      {
          get { return control; }
      }
  }

  2) Create a MouseDown event to start your dragging operation. Example:
  private void MyMouseDown(object sender, MouseEventArgs e)
  {
      Control source = (Control)sender;
      source.DoDragDrop(new MyWrapper(source), DragDropEffects.Move);
  }

  3) Assign the mouse event to all controls on your FlowLayoutPanel. Example:
  foreach (Control control in flowLayoutPanel1.Controls)
  {
      control.MouseDown += MyMouseDown;
  }
  If you add or remove controls at run-time, you can use the ControlAdded / ControlRemoved events of the FlowLayoutPanel to update your controls.

  4) Set the AllowDrop property of your FlowLayoutPanel to true.

  5) Create a DragEnter event for the FlowLayoutPanel. Example:
  private void flowLayoutPanel1_DragEnter(object sender, DragEventArgs e)
  {
      if (e.Data.GetDataPresent(typeof(MyWrapper)))
          e.Effect = DragDropEffects.Move;
      else
          e.Effect = DragDropEffects.None;
  }

  6) Create a DragDrop event for the FlowLayoutPanel. Example:
  private void flowLayoutPanel1_DragDrop(object sender, DragEventArgs e)
  {
      MyWrapper wrapper = (MyWrapper)e.Data.GetData(typeof(MyWrapper));
      Control source = wrapper.Control;
  
      Point mousePosition = flowLayoutPanel1.PointToClient(new Point(e.X, e.Y));
      Control destination = flowLayoutPanel1.GetChildAtPoint(mousePosition);
  
      int indexDestination = flowLayoutPanel1.Controls.IndexOf(destination);
      if (flowLayoutPanel1.Controls.IndexOf(source) < indexDestination)
          indexDestination--;
  
      flowLayoutPanel1.Controls.SetChildIndex(source, indexDestination);
  }

  Note: controls like Buttons, Labels, TextBoxes, etc. will behave nicely. Controls like RichTextBoxes require extra attention.

  Regards, Tonn

  
  
• How to Move Controls at RunTime in a flowLayoutPanel Control?