sharepoint-2010 - Sharepoint 自定义字段和 SPFieldMultiColumnValue

Question

我正在尝试研究 SharePoint 中的自定义字段。谁能帮我研究下面指定的 SPFieldMultiColumnValue。

    public override object Value
    {
        get
        {
            this.EnsureChildControls();

            SPFieldMultiColumnValue mcv = new SPFieldMultiColumnValue(2);
            mcv[0] = txtDurationId.Text;
            mcv[1] = DDLDurationID.SelectedValue;

            return mcv;
        }
        set
        {
            this.EnsureChildControls();

            SPFieldMultiColumnValue mcv = (SPFieldMultiColumnValue)this.ItemFieldValue;
            txtDurationId.Text = mcv[0];
            DDLDurationID.SelectedValue = mcv[1];
        }
    }