#1,051 – How the GridSplitter Behaves when Cells Use Auto Sizing

If one or both columns on either size of a GridSplitter (in its own column) have a width set to Auto, the behavior is as follows (“proportional” refers to star sizing):

• Both columns set to Auto: Left column changes size and is switched to Absolute sizing
• Left column Auto, right column proportional: Both columns change size, left switches to Absolute, right remains at original proportion (e.g. “1*”)
• Right column Auto, left column proportional: Both columns change size, right switches to Absolute, left remains at original proportion

In the example below, columns 0 and 2 surround a GridSplitter in column 1.  Columns 0 and 2 are set to Auto size (as is the column with the GridSplitter) and column 3 is set to proportional.

Initially, we see that both columns 0 and 2 are auto-sized.

If we slide the GridSplitter to the right, column 0 changes size and switches to Absolute sizing.  Column 2 remains as Auto.