値の選択が開始する位置
スピン編集 (PRIM_MD.SpinEdit) のメンバ
データタイプ - 整数
The SelectionStart property is the character position that selection begins within the text.
If the cursor is to the left of the first character, the value will be 0.
SelectionStart is provided for completeness and is unlikely to be required for most development purposes.