自定義動作。修改使用者自定義操作

string urlWebsite = "http://MyServer/sites/SiteCollection";
ClientContext clientContext = new ClientContext(urlWebsite);
Web oWebsite = clientContext.Web;

List oList = oWebsite.Lists.GetByTitle("My List");
UserCustomActionCollection collUserCustomAction = oList.UserCustomActions;

clientContext.Load(collUserCustomAction,
    userCustomActions => userCustomActions.Include(
        userCustomAction => userCustomAction.Title));

clientContext.ExecuteQuery();

foreach (UserCustomAction oUserCustomAction in collUserCustomAction)
{
    if (oUserCustomAction.Title == "My First User Custom Action")
    {
        oUserCustomAction.ImageUrl = "http://MyServer/_layouts/images/MyIcon.png";
        oUserCustomAction.Update();

        clientContext.ExecuteQuery();
    }
}