Gets or sets a value indicating whether the downward diagonal border should be displayed in a cell.
true, to display a downward diagonal border; otherwise, false.
Use the DiagonalDown property to display a diagonal border that extends from the top-left to the bottom-right corner of a cell. Note that this property takes effect only when the border line style is specified. To set the line style for the cell’s diagonal borders, use the XlBordersBase.DiagonalLineStyle property.
To set the color of a downward diagonal border, use the XlBorder.DiagonalColor property. If you do not define the border color, the automatic color is used.
You can also use the XlBordersBase.DiagonalDownLineStyle property to specify and display a downward diagonal border in a cell. This property automatically assigns the selected line style to the XlBordersBase.DiagonalLineStyle property and sets the DiagonalDown property to true.
To specify any other cell borders (e.g., top, bottom, left, right and outside borders), use the corresponding properties and methods of the XlBorder object. For more information on how to set cell borders, refer to the How to: Add Cell Borders example.