private void btnDeleteStep_Click(object sender, EventArgs e)
{
if (_presentation != null && selectPointIndex != -1)
{
_presentation.DeleteStep(indexInPresentation);
//更新表格
dt.Rows.RemoveAt(selectPointIndex);
for (int i = selectPointIndex; i < dt.Rows.Count; i++)
{
DataRow dr = dt.Rows[i];
int oldValue = int.Parse(dr[0].ToString());
dr[0] = oldValue - 1;
}
}
}