invalidcastexception derived treenode

invalidcastexception derived treenode

• Nazzo

  now i try...

  i have modified some lines

  if (node.Text == "organization"){

  Organization org;

  object objGeneral = node;

  string type = objGeneral.GetType().ToString();

  MessageBox.Show(type.ToString());

  if (objGeneral is Organization){

  org = (Organization)objGeneral;

  ecc...

  }}

  else{

  Object objGeneral2 = node;

  objGeneral2 = (Organization)xmlOrg;

  string type2= objGeneral2.GetType().ToString();

  MessageBox.Show(type2);

  if (objGeneral2 is Organization){

  xmlOrg = (Organization)objGeneral2;

  if (xmlOrg == null)

  ecc

  i see that when i save from a new treeview (here there arent exception) the type of the object objGeneral = node; is organization (so is a class type)

  when i save from an opened xml file the type of object objGeneral = node; is treenode

  here is the problem i want to convert the treenode in organization..

  what u think is possible

  tnx

  
  

• crystak

  org = (organization) treeview2.selectednode;

  Unable to cast object of type 'System.Windows.Forms.TreeNode' to type 'Tesi.Organization'.

  the exception is thrown on the selectednode and not on org...

  what i have to do to solve this problem really i dont know how to solve this...

  
  

• anderl

  hi,

  you lost me here , would you post part of your code which indicate where is the problem

  best regards

  
  
  

• Jiteshk

  Write like this to avoid invalid cast exceptions

  if (treeview2.SelectedNode is Organization)
  {
  org = treeview2.SelectedNode as Organization;
  // ...
  }

  this will also give same result

  org = treeview2.SelectedNode as Organization;
  if (org != null)
  {
  // ...
  }

  
  
  

• introne

  Did you try it where you able to resolve the problem
  
  Thank you,
  Bhanu.
  
  

• BLanders

  Are you really sure that the node that gives InvalidCastException is Organization derived from TreeNode

  You should not rely on exceptions to control flow of your program. You can use the is keyword to find out if a object is of a certain type

  if (node is Organization)
  {
  // handle if it is of type Organization
  }
  else
  {
  // handle node as if it is TreeNode
  }

  Also the code below is redundandt

  catch (InvalidCastException)
  {
  TreeNode nodeI = new TreeNode();
  nodeI = node;
  Object objGeneral = nodeI;

  node is enforced to be of type TreeNode because it is in the foreach() statement.

  
  
  

• DickM

  that's the function to save xml files...thanks for helping me

  private void saveNode(TreeNodeCollection tnc) {

  foreach (TreeNode node in tnc){

  if (node.Text == "organizations"){

  try{

  xr.WriteStartElement(node.Text);

  xr.WriteStartAttribute("default_organization");

  xr.WriteValue(orgs.p_default_organization);

  xr.WriteEndAttribute();

  saveNode(node.Nodes);

  xr.WriteEndElement();}

  catch (ArgumentNullException){

  MessageBox.Show("Please compile every field!", "Organizations Form Error", MessageBoxButtons.OK, MessageBoxIcon.Error);

  // orgform = new OrganizationForm;

  orgsform = new OrganizationsForm(orgs);

  orgs.FormOrgs = orgsform;

  orgs.FormOrgs.Show();}}

  if (node.Text == "organization"){

  try{

  org = (Organization)node;

  try{

  xr.WriteStartElement(node.Text);

  xr.WriteStartAttribute("id_organization");

  xr.WriteValue(org.p_id_organization);

  xr.WriteEndAttribute();

  xr.WriteStartAttribute("channel_type");

  xr.WriteValue(org.p_channel_organization);

  xr.WriteEndAttribute();

  xr.WriteStartAttribute("struct_organization");

  xr.WriteValue("hierarchical");

  xr.WriteEndAttribute();

  xr.WriteElementString("title", org.p_title_organization);

  saveNode(node.Nodes);

  xr.WriteEndElement();}

  catch (ArgumentNullException){

  MessageBox.Show("Please compile every field!", "Organization Form Error", MessageBoxButtons.OK, MessageBoxIcon.Error);

  orgform = new OrganizationForm(org);

  org.FormOrg = orgform;

  org.FormOrg.Show();}}

  catch (InvalidCastException){

  TreeNode nodeI = new TreeNode();

  nodeI = node;

  Object objGeneral = nodeI;

  Organization orgI = objGeneral as Organization;

  orgI = (Organization)objGeneral;

  if (orgI != null){

  try{

  xr.WriteStartElement(nodeI.Text);

  xr.WriteStartAttribute("id_organization");

  xr.WriteValue(org.p_id_organization);

  xr.WriteEndAttribute();

  xr.WriteStartAttribute("channel_type");

  xr.WriteValue(org.p_channel_organization);

  xr.WriteEndAttribute();

  xr.WriteStartAttribute("struct_organization");

  xr.WriteValue("hierarchical");

  xr.WriteEndAttribute();

  xr.WriteElementString("title", org.p_title_organization);

  saveNode(node.Nodes);

  xr.WriteEndElement();}

  catch (ArgumentNullException){

  MessageBox.Show("Please compile every field!", "Organization Form Error", MessageBoxButtons.OK, MessageBoxIcon.Error);

  orgform = new OrganizationForm(org);

  org.FormOrg = orgform;

  org.FormOrg.Show();}}

  else{

  break;

  }

  }

  }

  
  
• invalidcastexception derived treenode