复选框检查不起作用

Question

我在 gridview 中有 4-5 checkbox 个。我想将其值保存到数据库中，例如

如果checked == true，则"Y"否则"N"

但出现错误

object reference not set to an instance of an object

我将所有复选框定义如下

GridDataControlFieldCell chkcellAdd = GrdRights.RowsInViewState[i].Cells[4] as GridDataControlFieldCell;
GridDataControlFieldCell chkcellView = GrdRights.RowsInViewState[i].Cells[5] as GridDataControlFieldCell;
GridDataControlFieldCell chkcellEdit= GrdRights.RowsInViewState[i].Cells[6] as GridDataControlFieldCell;
GridDataControlFieldCell chkcellDelete = GrdRights.RowsInViewState[i].Cells[7] as GridDataControlFieldCell;

CheckBox chkadd = chkcellAdd.FindControl("ChkIDAdd") as CheckBox;
CheckBox chkview = chkcellView.FindControl("ChkIDView") as CheckBox;
CheckBox chkedit = chkcellEdit.FindControl("ChkIDEdit") as CheckBox;
CheckBox chkdelete = chkcellDelete.FindControl("ChkIDDelete") as CheckBox;

我尝试了 here 中的 link，但出现了同样的错误。

请指出这里有什么问题

HTML 我的 gridview:-

<cc2:Grid ID="GrdRights" runat="server" FolderStyle="../Styles/Grid/style_12"
    AllowSorting="False" AutoGenerateColumns="False" AllowColumnResizing="true" AllowAddingRecords="false"
    AllowMultiRecordSelection="true" OnRowDataBound="GrdRights_RowDataBound" ViewStateMode="Enabled"
    PageSize="100">
    <ClientSideEvents OnClientSelect="FunMonthList" />
    <ScrollingSettings ScrollHeight="400px" />
    <Columns>
        <cc2:Column ID="Column1" DataField="MKEY" ShowHeader="false" HeaderText="Select" ReadOnly="true"
            Width="5%" runat="server">
            <TemplateSettings TemplateId="TemplateWithCheckbox" />
        </cc2:Column>

        <cc2:Column ID="Column2" DataField="parent_menu" HeaderText="MENU" Visible="true"
            ReadOnly="true" Width="10%" runat="server">
        </cc2:Column>
        <cc2:Column ID="Column4" DataField="child_menu_mkey" Visible="false" ReadOnly="true"
            Width="10%" runat="server">
        </cc2:Column>
        <cc2:Column ID="Column3" DataField="child_menu" HeaderText="SUB MENU" runat="server"
            Visible="true" Width="30%">
        </cc2:Column>

          <%--<cc2:Column ID="Column5" DataField="MKEY" ShowHeader="false" HeaderText="Select"                                                  ReadOnly="true" Width="5%" runat="server">
            <TemplateSettings TemplateId="TemplateWithCheckbox" />
        </cc2:Column>--%>

        <cc2:CheckBoxColumn Id="chkAdd" DataField="ADD_FLAG" ShowHeader="true" HeaderText="Add"
            Width="5%" runat="server" Align="right">
            <TemplateSettings TemplateId="TemplateWithChecAdd"  />
        </cc2:CheckBoxColumn>

        <cc2:CheckBoxColumn Id="chkEdit" DataField="MODIFY_FLAG" ShowHeader="true" HeaderText="Edit"
            Width="5%" runat="server" Align="right">
            <TemplateSettings TemplateId="TemplateWithChecEdit" />
        </cc2:CheckBoxColumn>

        <cc2:CheckBoxColumn Id="ChkView" DataField="VIEW_FLAG" ShowHeader="true" HeaderText="View"
            Width="6%" runat="server" Align="right">
            <TemplateSettings TemplateId="TemplateWithChecView" />
        </cc2:CheckBoxColumn>

        <cc2:CheckBoxColumn Id="ChkDelete" DataField="DEL_FLAG" ShowHeader="true" HeaderText="Delete"
            Width="8%" runat="server" Align="right"> 
            <TemplateSettings TemplateId="TemplateWithChecDelete" />
        </cc2:CheckBoxColumn>

    </Columns>
    <Templates>

        <cc2:GridTemplate ID="TemplateWithChecAdd">
            <Template>
                <asp:CheckBox runat="server" ID="ChkIDAdd" ToolTip="<%# Container.Value %>"  />
            </Template>
        </cc2:GridTemplate>

        <cc2:GridTemplate ID="TemplateWithChecView">
            <Template>
                <asp:CheckBox runat="server" ID="ChkIDView" ToolTip="<%# Container.Value %>" />
            </Template>
        </cc2:GridTemplate>

        <cc2:GridTemplate ID="TemplateWithChecEdit">
            <Template>
                <asp:CheckBox runat="server" ID="ChkIDEdit" ToolTip="<%# Container.Value %>" />
            </Template>
        </cc2:GridTemplate>

        <cc2:GridTemplate ID="TemplateWithChecDelete">
            <Template>
                <asp:CheckBox runat="server" ID="ChkIDDelete" ToolTip="<%# Container.Value %>" />
            </Template>
        </cc2:GridTemplate>

    </Templates>
</cc2:Grid>

更新

根据我现在的代码，我得到了复选框值，但数据没有插入到 table 中，我收到错误消息

Column name 'ADD_FLAG' appears more than once in the result column list. Msg 264, Level 16, State 1, Line 1

Column name 'MODIFY_FLAG' appears more than once in the result column list. Msg 264, Level 16, State 1, Line 1

Column name 'VIEW_FLAG' appears more than once in the result column list. Msg 264, Level 16, State 1, Line 1

Column name 'DEL_FLAG' appears more than once in the result column list.

下面是我的代码：-

public bool Save()
{
    try
    {
        for (int i = 0; i < GrdRights.RowsInViewState.Count; i++)
        {
            string strSQLMKEY = "SELECT WMS_User_Rights.MKEY  FROM WMS_User_Rights Inner JOIN WMS_Menu_Rights on " +
                                       "WMS_User_Rights.User_Id = WMS_Menu_Rights.Mkey " +
                                       "where WMS_User_Rights.User_Id='" + Hid_Selected_user.Value + "' " +
                                       "AND WMS_User_Rights.DELETE_FLAG = 'N'";
            if (GrdRights.Rows[i].Cells[GrdRights.Columns.GetColumnIndexByDataField("child_menu_mkey")].Text.Trim().ToString() == "0")
            {
                strSQLMKEY += " and MENU_MKEY='" + GrdRights.Rows[i].Cells[GrdRights.Columns.GetColumnIndexByDataField("MKEY")].Text.Trim() + "'";
            }
            else
            {
                strSQLMKEY += " and MENU_MKEY='" + GrdRights.Rows[i].Cells[GrdRights.Columns.GetColumnIndexByDataField("child_menu_mkey")].Text.Trim() + "'";
            }
            con.Open();
            SqlCommand cmdMKEY = new SqlCommand(strSQLMKEY, con);
            if (cmdMKEY.ExecuteScalar() != null)
            {
                strMode = "M";
                iMKey = Convert.ToInt32(cmdMKEY.ExecuteScalar());
            }
            else
            {
                strMode = "A";
                iMKey = 0;
            }
            con.Close();
            System.Text.StringBuilder StrPubBldg = new System.Text.StringBuilder();
            XmlWriter xw = XmlWriter.Create(StrPubBldg);
            xw.WriteStartElement("DocumentElement");
            {
                xw.WriteStartElement("WMS_Menu_Rights");
                for (int j = 0; j < GrdRights.RowsInViewState.Count; j++)
                {
                    bool str_checkadd = ((CheckBox)((GridDataControlFieldCell)GrdRights.RowsInViewState[j].Cells[4]).FindControl("ChkIDAdd")).Checked;
                    bool str_checkEdit = ((CheckBox)((GridDataControlFieldCell)GrdRights.RowsInViewState[j].Cells[5]).FindControl("ChkIDEdit")).Checked;
                    bool str_checkView = ((CheckBox)((GridDataControlFieldCell)GrdRights.RowsInViewState[j].Cells[6]).FindControl("ChkIDView")).Checked;
                    bool str_checkdel = ((CheckBox)((GridDataControlFieldCell)GrdRights.RowsInViewState[j].Cells[7]).FindControl("ChkIDDelete")).Checked;

                    xw.WriteElementString("ADD_FLAG", str_checkadd == true ? "Y" : "N");
                    xw.WriteElementString("MODIFY_FLAG", str_checkEdit == true ? "Y" : "N");
                    xw.WriteElementString("VIEW_FLAG", str_checkView == true ? "Y" : "N");
                    xw.WriteElementString("DEL_FLAG", str_checkdel == true ? "Y" : "N");

                    if (GrdRights.Rows[i].Cells[GrdRights.Columns.GetColumnIndexByDataField("child_menu_mkey")].Text.Trim().ToString() == "0")
                    {
                        xw.WriteElementString("MENU_MKEY", GrdRights.Rows[i].Cells[GrdRights.Columns.GetColumnIndexByDataField("MKEY")].Text.Trim());
                    }
                    else
                    {
                        xw.WriteElementString("MENU_MKEY", GrdRights.Rows[i].Cells[GrdRights.Columns.GetColumnIndexByDataField("child_menu_mkey")].Text.Trim());
                    }
                    xw.WriteElementString("USER_ID", Hid_Selected_user.Value);
                    xw.WriteElementString("DELETE_FLAG", "N");
                    xw.WriteElementString("CREATION_DATE", System.DateTime.Now.ToString("dd/MM/yyyy hh:mm:ss"));
                }

                xw.WriteEndElement();
                xw.Close();
                MainEnqMkey = InsertUpdateDelete.InsertUpdateDeleteCls.InsertUpdateDelete_sql(strMode, Convert.ToInt16(iMKey), "WMS_Menu_Rights", "MKEY", "MUR", StrPubBldg.ToString());
            }

        }
        if (MainEnqMkey.Equals(0))
        {
            ClientScript.RegisterStartupScript(this.GetType(), "SuccessScript", "alert('Some Error Occured While Saving Data !!')", true);
        }
        else
        {
            con.Open();
            SqlCommand ObjPriCmd = new SqlCommand("delete from WMS_User_rights where MKEY=" + HidTempMkey.Value, con);
            ObjPriCmd.ExecuteNonQuery();
            con.Close();

            if (!Directory.Exists(Server.MapPath(StrFolder)))
            {
                Directory.CreateDirectory(Server.MapPath(StrFolder));
            }
            if (File.Exists(Server.MapPath(StrFolder + StrFileName)) == false)
            {
                using (System.IO.StreamWriter sw = File.CreateText(Server.MapPath(StrFolder + StrFileName)))
                {
                    sw.WriteLine("\n");

                    sw.WriteLine("\n"); sw.NewLine = "\n------------------------------------------------------------------";
                    sw.WriteLine("\n");
                    sw.Close();
                    sw.Dispose();
                }
            }
            else
            {
                using (System.IO.StreamWriter sw = File.AppendText(Server.MapPath(StrFolder + StrFileName)))
                {

                    sw.WriteLine("\n");

                    sw.WriteLine("\n"); sw.NewLine = "------------------------------------------------------------------";
                    sw.WriteLine("\n");
                    sw.Close();
                    sw.Dispose();
                }
            }
        }
        return true;
    }
    catch (Exception ex)
    {
        if (!Directory.Exists(Server.MapPath(StrFolder)))
        {
            Directory.CreateDirectory(Server.MapPath(StrFolder));
        }
        if (File.Exists(Server.MapPath(StrFolder + StrFileName)) == false)
        {
            using (System.IO.StreamWriter sw = File.CreateText(Server.MapPath(StrFolder + StrFileName)))
            {
                sw.WriteLine("\n");

                sw.WriteLine("\n"); sw.NewLine = "\n------------------------------------------------------------------";
                sw.WriteLine("\n");
                sw.Close();
                sw.Dispose();
            }
        }
        else
        {
            using (System.IO.StreamWriter sw = File.AppendText(Server.MapPath(StrFolder + StrFileName)))
            {

                sw.WriteLine("\n");

                sw.WriteLine("\n"); sw.NewLine = "------------------------------------------------------------------";
                sw.WriteLine("\n");
                sw.Close();
                sw.Dispose();
            }
        }
        return false;
    }

    finally
    {

    }

}

protected void CmdSave_Click(object sender, EventArgs e)
{
    if (Save() == true)
    {
        fillGrid();
        if (strMode == "M")
        {
            ClientScript.RegisterStartupScript(this.GetType(), "CloseScript", "alert('Record Modified Successfully');window.location.href='Frm_User_Rights.aspx?TranType=MUR&Mode=A&Key=0&PView=N&userid=" + Request.QueryString["userid"].ToString() + "';", true);
        }
        else
        {
            ClientScript.RegisterStartupScript(this.GetType(), "CloseScript", "alert('Record Saved Successfully');window.location.href='Frm_User_Rights.aspx?TranType=MUR&Mode=A&Key=0&PView=N&userid=" + Request.QueryString["userid"].ToString() + "';", true);
        }
    }
}

Answer 1

每个 GridViewRow 都包含这些复选框，并且是它们的 NamingContainer-控件，其中每个 ID 必须是唯一的，因此您需要在每一行上使用 FindControl：

foreach (GridViewRow row in GrdRights.Rows)
{
    CheckBox chkadd = row.FindControl("ChkIDAdd") as CheckBox;
    CheckBox chkview = row.FindControl("ChkIDView") as CheckBox;
    CheckBox chkedit = row.FindControl("ChkIDEdit") as CheckBox;
    CheckBox chkdelete = row.FindControl("ChkIDDelete") as CheckBox;
    xw.WriteElementString("ADD_FLAG", chkadd.Checked == true ? "Y" : "N");
    xw.WriteElementString("MODIFY_FLAG", chkedit.Checked == true ? "Y" : "N");
    xw.WriteElementString("VIEW_FLAG", chkview.Checked == true ? "Y" : "N");
    xw.WriteElementString("DEL_FLAG", chkdelete.Checked == true ? "Y" : "N");
}

我对 obout Grid 不熟悉，但这似乎适合你：

for (int j = 0; j < GrdRights.RowsInViewState.Count; j++)
{
    bool str_checkadd = ((CheckBox)((GridDataControlFieldCell)GrdRights.RowsInViewState[j].Cells[4]).FindControl("ChkIDAdd")).Checked;
    bool str_checkEdit = ((CheckBox)((GridDataControlFieldCell)GrdRights.RowsInViewState[j].Cells[5]).FindControl("ChkIDEdit")).Checked;
    bool str_checkView = ((CheckBox)((GridDataControlFieldCell)GrdRights.RowsInViewState[j].Cells[6]).FindControl("ChkIDView")).Checked;
    bool str_checkdel = ((CheckBox)((GridDataControlFieldCell)GrdRights.RowsInViewState[j].Cells[7]).FindControl("ChkIDDelete")).Checked;
    // ....
}

但即使有了这个我不知道的RowsInViewState，也应该可以使用这个更简单的代码：

for (int j = 0; j < GrdRights.RowsInViewState.Count; j++) { CheckBox checkadd = (CheckBox) GrdRights.RowsInViewState[j].FindControl("ChkIDAdd"); CheckBox checkEdit = (CheckBox) GrdRights.RowsInViewState[j].FindControl("ChkIDEdit"); CheckBox chkView = (CheckBox) GrdRights.RowsInViewState[j].FindControl("ChkIDView"); CheckBox chkDel= (CheckBox) GrdRights.RowsInViewState[j].FindControl("ChkIDDel"); // .... }

Answer 2

好吧，我在 grid-view 方面经验不多，但我认为你循环的方式不对..你正在循环每一行，包括 header，所以请检查该行是否 data-row 然后尝试找到 check-boxes

这是我找到的一些代码，希望对您有所帮助

 foreach (GridViewRow row in GridView1.Rows)
{
    if (row.RowType == DataControlRowType.DataRow)
    {
        CheckBox chkRow = (row.Cells[0].FindControl("chkRow") as CheckBox);
        if (chkRow.Checked)
        {
    //your code
        }
    }
}

复选框检查不起作用

Checkbox check is not working

c#

asp.net

gridview

checkbox

obout