To reproduce:

1. Add three SplitPanels in horizontal mode.

2. Use the following code snippet.

3. Drag the second splitter upwards. It changes the height on the first panel

void RadForm1_Load(object sender, EventArgs e)
{
    FixHeight(splitPanel1);
    FixHeight(splitPanel3);
}

public static void FixHeight(SplitPanel panel)
{
    panel.SizeInfo.MinimumSize = new Size(0, 55);
    panel.SizeInfo.MaximumSize = new Size(0, 55);
}

In this particular case, the main monitor has 125% DPI. When showing a RadForm which contains RadSplitContainer with 2 panels, the control is not scaled correctly.

Expected:

Current behavior:

Workaround:

Set the RadControl.EnableRadAutoScale property to false.

To reproduce:
- Use relative sizing and save the RelativeRatio.
- Set the same value after restarting the application.
- The panel size is not the same. 

Workaround:
Use absolute size. 

To reproduce:

Add a RadSplitContainer with several SplitPanels and use the following code:
  this.radSplitContainer1.EnableCollapsing = true;
  this.radSplitContainer1.UseSplitterButtons = true;

If you run the project, you will notice that the next/previous buttons are displayed for manipulating the SplitPanel's collapsed/expanded state. If you click one of the next/previous buttons, the relevant SplitPanel will be collapsed and the splitter will remain visible. Thus, the user has the possibility to return the previous state of the SplitPanel. However, if you try to collapse the SplitPanel programmatically by setting the Collapsed property to true, the corresponding splitter will disapper.

The scenario that we want to cover is to disable resizing the split panels but still enable the option for expanding/collapsing them via the buttons.

Add right to left support.

This should be the same as in the standard split container – the panels should be swapped.

To reproduce: add a RadSplitContainer with 3 identical SplitPanels. The left panel needs to be initially collapsed. That is why we use the introduced public API (MoveSplitter method). When the form is shown and you try to expand the left (yellow) panel, you will notice that the splitter is not restored to the correct position. Please refer to the attached gif file.

This must be handled for Vertical and Horizontal orientation!!!

Workaround:

Private Sub RadForm1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    AddHandler Me.RadSplitContainer1.MouseDown, AddressOf SplitContainerMouseDown
End Sub
Private Sub SplitContainerMouseDown(sender As Object, e As MouseEventArgs)
    Dim clickedElement = Me.RadSplitContainer1.ElementTree.GetElementAtPoint(e.Location)
    If TypeOf clickedElement Is SplitterElement Or TypeOf (clickedElement.Parent) Is SplitterElementLayout Then
        RadSplitContainer1.RestoreSplitterPosition(Me.RadSplitContainer1.Splitters(0))
        RemoveHandler Me.RadSplitContainer1.MouseDown, AddressOf SplitContainerMouseDown
    End If
End Sub

How to reproduce: check the attached project
Workaround: check the attached project

I have three split panels and when the auto scroll is enabled some lines appear in the split panel.

The issue can be reproduced with RadPanel as well.

Workaround: http://www.telerik.com/forums/problem-with-auto-scroll#ygV1vwyA40KZ4KoD28AhvQ

If the AutoScroll of RadSplitContainer is true and I scroll the container a little, don’t work the resizes of the panels.

sample code:

public Form1()
    {
        InitializeComponent();
 
        RadSplitContainer radSplitContainer1 = new RadSplitContainer()
        {
            Dock = DockStyle.Fill,
            AutoScroll = true
        };
 
        this.Controls.Add(radSplitContainer1);
 
        for (int i = 0; i < 10; i++)
        {
            var panel = new SplitPanel();
            panel.SizeInfo.SizeMode = SplitPanelSizeMode.Absolute;
            panel.SizeInfo.AbsoluteSize = new Size(100, 0);
            radSplitContainer1.SplitPanels.Add(panel);
        }
    }

To reproduce:
- Add button to a split panel
- Set button Text property to "Button &X"
- Add a event handler for the button
- Start the application and press the "x" key

To work around this issue instead of using mnemonics you can set shortcuts like this:
radButton.ButtonElement.Shortcuts.Add(new RadShortcut(Keys.Alt, Keys.X));

Also you can set mnemonic like underline like this:
radButton.Text = "<html>Button <u>X";

To reproduce:
-add RadSplitContainer (horizontal) and add one left and one right split panel
-add two RadButtons to collapse and show one of the panels
private void radButton1_Click(object sender, EventArgs e)
{
    this.splitPanel1.Collapsed = true;
}

private void radButton2_Click(object sender, EventArgs e)
{          
    this.splitPanel1.Visible = true;
}
-click the first button to collapse the left panel; as a result the second panel fills the entire container size
-click the second button to show again the left panel; as a result the panels overlap each other