Error when Updating a web part - sharepoint-2010

Question

I am developping a web part that I can't update on the SharePoint server without deleting it in webpart gallery. Then, I run in power shell :
Update-SPSolution ...
Disable-SPFeature ...
Enable-SPFeature ...
I tried to delete the web part in the gallery programmatically in the event receiver, but it causes SharePoint to fail :
public override void FeatureDeactivating(SPFeatureReceiverProperties properties)
{
SPSite site = properties.Feature.Parent as SPSite;
using (SPWeb web = site.RootWeb)
{
SPList list = web.Lists["Web Part Gallery"];
// go through the items in reverse
for (int i = list.ItemCount - 1; i >= 0; i--)
{
// format name to look like a feature name
string webpartName = list.Items[i].Name;
webpartName = webpartName.Substring(0, webpartName.IndexOf('.'));
// delete web parts that have been added
if (properties.Feature.Definition.DisplayName == webpartName)
{
list.Items[i].Delete();
break;
}
}
}
}
Any idea what am i doing wrong ? thx

Answer 1

I am coming back to share the solution.
Here is the correct code to delele the web part from the gallery when deactivating the feature :
public override void FeatureDeactivating(SPFeatureReceiverProperties properties)
{
try
{
int ItemID = -1;
using (SPSite oSite = (SPSite)(properties.Feature.Parent))
{
using (SPWeb oWeb = oSite.RootWeb)
{
SPList oList = oWeb.Lists["Galerie de composants WebPart"];
if (oList == null)
{
// si SharePoint en anglais
oList = oWeb.Lists["Web Part Gallery"];
}
// si oList == null, alors aucun de traitement
// on ne connais pas le nom de la liste
// de la gallerie de web part
if (oList != null)
{
for (int i = 0; i < oList.ItemCount; i++)
{
if (oList.Items[i].Title.Equals(WebPartTitle))
{
ItemID = oList.Items[i].ID;
break;
}
}
if (ItemID != -1)
{
SPListItem oItem = oList.GetItemById(ItemID);
oItem.Delete();
oList.Update();
}
}
}
}
}
catch (Exception e)
{
//will throw to and error page
throw new Exception(String.Format("The has been an error "
+ "removing the WebPart from the Gallery; {0}", e.ToString()));
}
}
Finally, after adding this code in the event receiver, the procedure for updating the Web Part solution is :
Disable-SPFeature ...
Uninstall-SPFeature ...
Update-SPSolution ...
Install-SPFeature ...
Enable-SPFeature ...
Hope it helps