protected void HideCheckBox(TV_ITEM tv_item)
{
if (tv_item.ItemHandle != IntPtr.Zero)
{
// get TreeNode-object, that corresponds to TV_ITEM-object
TreeNode currentTN = TreeNode.FromHandle(this, tv_item.ItemHandle);
HiddenCheckBoxTreeNode hiddenCheckBoxTreeNode = currentTN as HiddenCheckBoxTreeNode;
// check if it's HiddenCheckBoxTreeNode and
// if its checkbox already has been hidden
if (hiddenCheckBoxTreeNode != null)
{
HandleRef treeHandleRef = new HandleRef(this, Handle);
// check if checkbox already has been hidden
TV_ITEM currentTvItem = new TV_ITEM();
currentTvItem.ItemHandle = tv_item.ItemHandle;
currentTvItem.StateMask = TVIS_STATEIMAGEMASK;
currentTvItem.State = 0;
IntPtr res = SendMessage(treeHandleRef, TVM_GETITEM, 0, ref currentTvItem);
bool needToHide = res.ToInt32() > 0 && currentTvItem.State != 0;
if (needToHide)
{
// specify attributes to update
TV_ITEM updatedTvItem = new TV_ITEM();
updatedTvItem.ItemHandle = tv_item.ItemHandle;
updatedTvItem.Mask = TVIF_STATE;
updatedTvItem.StateMask = TVIS_STATEIMAGEMASK;
updatedTvItem.State = 0;
// send TVM_SETITEM message
SendMessage(treeHandleRef, TVM_SETITEM, 0, ref updatedTvItem);
}
}
}
}
protected void HideCheckBox(TV_ITEM tv_item)
{
if (tv_item.ItemHandle != IntPtr.Zero)
{
// get TreeNode-object, that corresponds to TV_ITEM-object
TreeNode currentTN = TreeNode.FromHandle(this, tv_item.ItemHandle);
Custom_HiddenCheckBoxTreeNode hiddenCheckBoxTreeNode = currentTN as Custom_HiddenCheckBoxTreeNode;
// check if it's HiddenCheckBoxTreeNode and
// if its checkbox already has been hidden
if (hiddenCheckBoxTreeNode != null && !hiddenCheckBoxTreeNode.CheckboxHidden)
{
// to evade repeat hiding, we set CheckboxHidden to true
hiddenCheckBoxTreeNode.CheckboxHidden = true;
// specify attributes to update
TV_ITEM updatedTvItem = new TV_ITEM();
updatedTvItem.ItemHandle = tv_item.ItemHandle;
updatedTvItem.Mask = TVIF_STATE;
updatedTvItem.StateMask = TVIS_STATEIMAGEMASK;
updatedTvItem.State = 0;
// send TVM_SETITEM message
SendMessage(new HandleRef(this, Handle), TVM_SETITEM, 0, ref updatedTvItem);
}
}
}
protected void HideCheckBox(TV_ITEM tv_item)
{
if (tv_item.ItemHandle != IntPtr.Zero)
{
// get TreeNode-object, that corresponds to TV_ITEM-object
TreeNode currentTN = TreeNode.FromHandle(this, tv_item.ItemHandle);
Custom_HiddenCheckBoxTreeNode hiddenCheckBoxTreeNode = currentTN as Custom_HiddenCheckBoxTreeNode;
// check if it's HiddenCheckBoxTreeNode and
// if its checkbox already has been hidden
if (hiddenCheckBoxTreeNode != null && !hiddenCheckBoxTreeNode.CheckboxHidden)
{
// to evade repeat hiding, we set CheckboxHidden to true
hiddenCheckBoxTreeNode.CheckboxHidden = true;
// specify attributes to update
TV_ITEM updatedTvItem = new TV_ITEM();
updatedTvItem.ItemHandle = tv_item.ItemHandle;
updatedTvItem.Mask = TVIF_STATE;
updatedTvItem.StateMask = TVIS_STATEIMAGEMASK;
updatedTvItem.State = 0;
// send TVM_SETITEM message
SendMessage(new HandleRef(this, Handle), TVM_SETITEM, 0, ref updatedTvItem);
}
}
}
private void SetNodeStateToMixed(TreeNode node)
{
var lParam = new TV_ITEM
{
mask = 0x18, // TVIF_HANDLE | TVIF_STATE
hItem = node.Handle,
stateMask = 0xf000, // TVIS_STATEIMAGEMASK
state = 0x3000
};
// ReSharper disable once InconsistentNaming
const int TVM_SETITEM = 0x110d;
SendMessage(new HandleRef(this.BackgroundObjectTree, this.BackgroundObjectTree.Handle), TVM_SETITEM, 0, ref lParam);
}
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
// trap TVM_SETITEM message
if (m.Msg == TVM_SETITEM || m.Msg == TVM_SETITEMA || m.Msg == TVM_SETITEMW)
// check if CheckBoxes are turned on
if (CheckBoxes)
{
// get information about the node
TV_ITEM tv_item = (TV_ITEM)m.GetLParam(typeof(TV_ITEM));
HideCheckBox(tv_item);
}
}
protected void HideCheckBox(TV_ITEM tv_item)
{
if (tv_item.ItemHandle != IntPtr.Zero && tv_item.ItemHandle != hidingItemHandle)
{
// get TreeNode-object, that corresponds to TV_ITEM-object
TreeNode currentTN = TreeNode.FromHandle(this, tv_item.ItemHandle);
HiddenCheckBoxTreeNode hiddenCheckBoxTreeNode = currentTN as HiddenCheckBoxTreeNode;
// check if it's HiddenCheckBoxTreeNode and
// if its checkbox already has been hidden
if (hiddenCheckBoxTreeNode != null)
{
HandleRef treeHandleRef = new HandleRef(this, Handle);
// check if checkbox already has been hidden
TV_ITEM currentTvItem = new TV_ITEM();
currentTvItem.ItemHandle = tv_item.ItemHandle;
currentTvItem.StateMask = TVIS_STATEIMAGEMASK;
currentTvItem.State = 0;
IntPtr res = SendMessage(treeHandleRef, TVM_GETITEM, 0, ref currentTvItem);
bool needToHide = res.ToInt32() > 0 && currentTvItem.State != 0;
if (needToHide)
{
// specify attributes to update
TV_ITEM updatedTvItem = new TV_ITEM();
updatedTvItem.ItemHandle = tv_item.ItemHandle;
updatedTvItem.Mask = TVIF_STATE;
updatedTvItem.StateMask = TVIS_STATEIMAGEMASK;
updatedTvItem.State = 0;
hidingItemHandle = tv_item.ItemHandle;
try
{
// send TVM_SETITEM message
SendMessage(treeHandleRef, TVM_SETITEM, 0, ref updatedTvItem);
}
finally
{
hidingItemHandle = IntPtr.Zero;
}
}
}
}
}
protected void HideCheckBox(TV_ITEM tv_item)
{
if (tv_item.ItemHandle != IntPtr.Zero)
{
// get TreeNode-object, that corresponds to TV_ITEM-object
var currentTN = TreeNode.FromHandle(this, tv_item.ItemHandle);
// check if it's HiddenCheckBoxTreeNode and
// if its checkbox already has been hidden
if (currentTN is HiddenCheckBoxTreeNode)
{
var treeHandleRef = new HandleRef(this, Handle);
// check if checkbox already has been hidden
var currentTvItem = new TV_ITEM
{
ItemHandle = tv_item.ItemHandle,
StateMask = TVIS_STATEIMAGEMASK,
State = 0
};
var res = SendMessage(treeHandleRef, TVM_GETITEM, 0, ref currentTvItem);
var needToHide = res.ToInt32() > 0 && currentTvItem.State != 0;
if (needToHide)
{
// specify attributes to update
var updatedTvItem = new TV_ITEM
{
ItemHandle = tv_item.ItemHandle,
Mask = TVIF_STATE,
StateMask = TVIS_STATEIMAGEMASK,
State = 0
};
// send TVM_SETITEM message
SendMessage(treeHandleRef, TVM_SETITEM, 0, ref updatedTvItem);
}
}
}
}
protected override void WndProc(ref Message m)
{
if (m.Msg == 0x0203) // WM_LBUTTONDBLCLK. dblclick is misbehaving with checkboxes.
{
m.Result = IntPtr.Zero;
return;
}
base.WndProc(ref m);
// trap TVM_SETITEM message
if (m.Msg == TVM_SETITEM || m.Msg == TVM_SETITEMA || m.Msg == TVM_SETITEMW)
{
// check if CheckBoxes are turned on
if (CheckBoxes)
{
// get information about the node
TV_ITEM tv_item = (TV_ITEM)m.GetLParam(typeof(TV_ITEM));
HideCheckBox(tv_item);
}
}
}
public static extern IntPtr SendMessage(HandleRef hWnd, int msg, int wParam, ref TV_ITEM lParam);
public static extern IntPtr SendMessage(HandleRef hWnd, int msg, int wParam, ref TV_ITEM lParam);
internal static extern IntPtr SendMessage(HandleRef hWnd, int Msg, IntPtr wParam, ref TV_ITEM lParam);