可為 Null 的型別概觀

http://msdn.microsoft.com/zh-tw/library/1t3y8s4s.aspx

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//20110218 jenny 法院解交
if (cmb_TrxTypeCode.SelectedItem.ToString() == "一般過戶" || cmb_TrxTypeCode.SelectedItem.ToString() == "法院解交")
{
if (frm_ReciverQ.cmb_ExcAcc.SelectedIndex != -1)//null處理
{
txt_ExcAccId.Tag = frm_ReciverQ.cmb_ExcAcc.SelectedValue.ToString();
txt_ExcAccId.Text = frm_ReciverQ.cmb_ExcAcc.SelectedText.ToString();
}
}