Databases
StackOverflow2013
Postsdbo
POGridView with DropDownList throws exception in Edit mode
Body
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POGridView with DropDownList throws exception in Edit mode
    text
    copied!<p>This is my full grid</p> <pre><code> &lt;div id="grid"&gt; &lt;asp:GridView ID="gridProduct" runat="server" AutoGenerateColumns="false" ShowFooter="true" onrowcancelingedit="gridProduct_RowCancelingEdit" onrowdeleting="gridProduct_RowDeleting" onrowediting="gridProduct_RowEditing" onrowupdating="gridProduct_RowUpdating" onrowcommand="gridProduct_RowCommand" onrowdatabound="gridProduct_RowDataBound"&gt; &lt;Columns&gt; &lt;asp:TemplateField&gt; &lt;EditItemTemplate&gt; &lt;asp:Button ID="buttonUpdate" CommandName="Update" runat="server" ToolTip="Update" Text="Update" /&gt; &lt;asp:Button ID="buttonCancel" CommandName="Cancel" runat="server" ToolTip="Cancel" Text="Cancel" /&gt; &lt;/EditItemTemplate&gt; &lt;ItemTemplate&gt; &lt;asp:Button ID="buttonEdit" CommandName="Edit" runat="server" Text="Edit" ToolTip="Edit"/&gt; &lt;asp:Button ID="buttonDelete" CommandName="Delete" runat="server" Text="Delete" ToolTip="Delete"/&gt; &lt;/ItemTemplate&gt; &lt;FooterTemplate&gt; &lt;asp:Button ID="buttonAdd" runat="server" Text="Ajouter" CommandName="AddNew" ToolTip="Add new User" ValidationGroup="validaiton" /&gt; &lt;/FooterTemplate&gt; &lt;/asp:TemplateField&gt; &lt;asp:TemplateField HeaderText="#Piece"&gt; &lt;EditItemTemplate&gt; &lt;asp:DropDownList ID="dropDownListPartsEdit" DataTextField="Nom" DataValueField="ID_AchatTemplate" runat="server" Text='&lt;%#Eval("Piece") %&gt;'/&gt; &lt;/EditItemTemplate&gt; &lt;ItemTemplate&gt; &lt;asp:Label ID="labelItemPiece" runat="server" Text='&lt;%#Eval("Piece") %&gt;'/&gt; &lt;/ItemTemplate&gt; &lt;FooterTemplate&gt; &lt;asp:DropDownList ID="dropDownListPartsFooter" runat="server" DataTextField="Nom" DataValueField="ID_AchatTemplate"&gt; &lt;/asp:DropDownList&gt; &lt;%--&lt;asp:TextBox ID="txtBoxPiece" runat="server"/&gt;--%&gt; &lt;%--&lt;asp:RequiredFieldValidator ID="fieldValidPiece" runat="server" ControlToValidate="txtBoxPiece" Text="*" ValidationGroup="validaiton"/&gt;--%&gt; &lt;/FooterTemplate&gt; &lt;/asp:TemplateField&gt; &lt;asp:TemplateField HeaderText="Series"&gt; &lt;EditItemTemplate&gt; &lt;asp:TextBox ID="txtBoxEditSeries" runat="server" Text='&lt;%#Eval("Series") %&gt;'/&gt; &lt;/EditItemTemplate&gt; &lt;ItemTemplate&gt; &lt;asp:Label ID="labelItemSeries" runat="server" Text='&lt;%#Eval("Series") %&gt;'/&gt; &lt;/ItemTemplate&gt; &lt;FooterTemplate&gt; &lt;asp:TextBox ID="txtBoxSeries" runat="server"/&gt; &lt;asp:RequiredFieldValidator ID="fieldValidSeries" runat="server" ControlToValidate="txtBoxSeries" Text="*" ValidationGroup="validaiton"/&gt; &lt;/FooterTemplate&gt; &lt;/asp:TemplateField&gt; &lt;asp:TemplateField HeaderText="Revision"&gt; &lt;EditItemTemplate&gt; &lt;asp:TextBox ID="textBoxEditRevision" runat="server" Text='&lt;%#Eval("Rev") %&gt;'/&gt; &lt;/EditItemTemplate&gt; &lt;ItemTemplate&gt; &lt;asp:Label ID="labelItemRevision" runat="server" Text='&lt;%#Eval("Rev") %&gt;'/&gt; &lt;/ItemTemplate&gt; &lt;FooterTemplate&gt; &lt;asp:TextBox ID="txtBoxRevision" runat="server"/&gt; &lt;asp:RequiredFieldValidator ID="fieldValidRevision" runat="server" ControlToValidate="txtBoxRevision" Text="*" ValidationGroup="validaiton"/&gt; &lt;/FooterTemplate&gt; &lt;/asp:TemplateField&gt; &lt;asp:TemplateField HeaderText="Firmware"&gt; &lt;EditItemTemplate&gt; &lt;asp:TextBox ID="textBoxEditFirmware" runat="server" Text='&lt;%#Eval("Firmware") %&gt;'/&gt; &lt;/EditItemTemplate&gt; &lt;ItemTemplate&gt; &lt;asp:Label ID="labelItemFirmware" runat="server" Text='&lt;%#Eval("Firmware") %&gt;'/&gt; &lt;/ItemTemplate&gt; &lt;FooterTemplate&gt; &lt;asp:TextBox ID="txtBoxFirmware" runat="server"/&gt; &lt;asp:RequiredFieldValidator ID="fieldValidFirmware" runat="server" ControlToValidate="txtBoxFirmware" Text="*" ValidationGroup="validaiton"/&gt; &lt;/FooterTemplate&gt; &lt;/asp:TemplateField&gt; &lt;/Columns&gt; &lt;/asp:GridView&gt; </code></pre> <p>This is my method event for editing. First I try to bind my dropDownList but I get an error "Object reference not set to an instance of an object."</p> <pre><code> protected void gridProduct_RowEditing(object sender, GridViewEditEventArgs e) { ClientParts getclient = new ClientParts(); ClientPartsSearchCriteria criteria = new ClientPartsSearchCriteria(); ((DropDownList)gridProduct.Rows[e.NewEditIndex].FindControl("dropDownListPartsEdit")).DataSource = getclient.Get(criteria); ((DropDownList)gridProduct.Rows[e.NewEditIndex].FindControl("dropDownListPartsEdit")).DataBind(); gridProduct.EditIndex = e.NewEditIndex; PsaDataSet psaList = (PsaDataSet)ViewState["psaList"]; BindGrid(psaList, false); } </code></pre> <p>I don't understand why "Object reference not set to an instance of an object." from this line</p> <pre><code>((DropDownList)gridProduct.Rows[e.NewEditIndex].FindControl("dropDownListPartsEdit")).DataSource = getclient.Get(criteria); </code></pre>
 

Querying!

 
Guidance
An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload