IsNull

System\Windows\Forms\Accessibility\Control.ControlAccessibleObject.cs (3)

258if (_handle.IsNull) 465if (HandleInternal.IsNull || AppContextSwitches.NoClientNotifications) 539if (HandleInternal.IsNull)

System\Windows\Forms\ActiveX\AxHost.cs (1)

3206if (!handle.IsNull)

System\Windows\Forms\ActiveX\AxHost.OleInterfaces.cs (1)

312if (!hwnd.IsNull)

System\Windows\Forms\ActiveX\Control.ActiveXImpl.cs (2)

360HWND hwndMap = hwnd.IsNull ? hwndParent : hwnd; 855if (PInvoke.SetParent(_control, hwndParent).IsNull)

System\Windows\Forms\Application.cs (1)

405if (hwnd.IsNull)

System\Windows\Forms\Application.ParkingWindow.cs (1)

93if (hwndChild.IsNull)

System\Windows\Forms\Application.ThreadContext.cs (3)

751if (!hwndOwner.IsNull) 801if (!hwndOwner.IsNull) 976if (!hwndRoot.IsNull && PInvoke.IsDialogMessage(hwndRoot, in msg))

System\Windows\Forms\Application.ThreadWindows.cs (2)

84if (!_activeHwnd.IsNull && PInvoke.IsWindow(_activeHwnd)) 89if (!_focusedHwnd.IsNull && PInvoke.IsWindow(_focusedHwnd))

System\Windows\Forms\Control.cs (25)

1491return !focusHwnd.IsNull && (focusHwnd == Handle || PInvoke.IsChild(this, focusHwnd)); 2445while (!parentHandle.IsNull) 2516!(next = PInvoke.GetWindow(prev, GET_WINDOW_CMD.GW_HWNDPREV)).IsNull; 5449while (!hwnd.IsNull) 5692!hWndChild.IsNull; 6019return hwnd.IsNull || PInvoke.IsWindow(hwnd) 7683if (PInvoke.SetParent(this, parent).IsNull) 9831PInvoke.GetParent(topMostParent).IsNull ? PInvokeCore.WM_CHANGEUISTATE : PInvokeCore.WM_UPDATEUISTATE, 10075!parentHandle.IsNull 10173if (!handle.IsNull) 10997if (parentHandle != value || (parentHandle.IsNull && !topLevel)) 11001bool recreate = (parentHandle.IsNull && !topLevel) 11002|| (value.IsNull && topLevel); 11027if (value.IsNull) 11034if (PInvoke.SetParent(this, value).IsNull) 11047else if (value.IsNull && parentHandle.IsNull && topLevel) 11052if (PInvoke.SetParent(this, HWND.Null).IsNull) 11687while (!(hWnd = PInvoke.GetWindow(hWnd, GET_WINDOW_CMD.GW_HWNDPREV)).IsNull) 11726if (!parentHandle.IsNull) 11871while (!parentHandle.IsNull) 11883if (!lastParentHandle.IsNull) 12527if (dialogItem.IsNull) 12543if (!handle.IsNull && FromHandle(handle) is { } control) 12774if (hWnd.IsNull || !ReflectMessage(hWnd, ref m))

System\Windows\Forms\Control.Ime.cs (2)

270if (!focusHandle.IsNull) 280if (!focusHandle.IsNull)

System\Windows\Forms\Controls\ComboBox\ComboBox.ComboBoxChildNativeWindow.cs (1)

60if (!HWND.IsNull)

System\Windows\Forms\Controls\ComboBox\ComboBox.cs (6)

589return !focus.IsNull 1952if (_childEdit is not null && !_childEdit.HWND.IsNull) 1957if (_childListBox is not null && !_childListBox.HWND.IsNull) 2368if (!hwnd.IsNull) 3450if (_dropDownHandle.IsNull) 3546if (_childEdit is not null && !_childEdit.HWND.IsNull)

System\Windows\Forms\Controls\ComboBox\ComboBox.Modern.cs (6)

67|| comboBoxInfo.hwndItem.IsNull 72&& !comboBoxInfo.hwndList.IsNull 293|| comboBoxInfo.hwndList.IsNull 437if (editHandle.IsNull) 467if (childHandle.IsNull 592|| dropDownHandle.IsNull

System\Windows\Forms\Controls\DateTimePicker\DateTimePicker.cs (1)

1442if (!c.hwndFound.IsNull)

System\Windows\Forms\Controls\ListView\ColumnHeader.cs (1)

396if (!hwndHdr.IsNull)

System\Windows\Forms\Controls\ListView\ListView.cs (3)

2188if (hwnd.IsNull) 3797if (!header.IsNull) 4943if (!headerWindow.IsNull)

System\Windows\Forms\Controls\PropertyGrid\PropertyGrid.cs (1)

3385if (!hWndParent.IsNull)

System\Windows\Forms\Controls\PropertyGrid\PropertyGridInternal\PropertyGridView.cs (3)

850gotFocus = !PInvoke.SetFocus(this).IsNull; 2562for (HWND hwnd = PInvokeCore.GetForegroundWindow(); !hwnd.IsNull; hwnd = PInvoke.GetParent(hwnd)) 4915if (!priorFocus.IsNull)

System\Windows\Forms\Controls\PropertyGrid\PropertyGridInternal\PropertyGridView.DropDownHolder.cs (2)

266while (!hWnd.IsNull) 269if (hWnd.IsNull)

System\Windows\Forms\Controls\TabControl\TabControl.cs (1)

1256if (!tooltipHwnd.IsNull)

System\Windows\Forms\Controls\ToolStrips\StatusStrip.cs (2)

172if (!rootHwnd.IsNull) 581if (!rootHwnd.IsNull && !PInvoke.IsZoomed(rootHwnd))

System\Windows\Forms\Controls\ToolStrips\ToolStrip.cs (3)

3999if (!_hwndThatLostFocus.IsNull && (_hwndThatLostFocus != Handle)) 4431if (thisHwndRoot == otherHwndRoot && !thisHwndRoot.IsNull) 4648if (!rootHwnd.IsNull)

System\Windows\Forms\Controls\ToolStrips\ToolStripManager.ModalMenuFilter.cs (4)

133if (!hwndActive.IsNull) 188if (!ActiveHwnd.Handle.IsNull) 403if (!hwndActive.IsNull) 533if (activeWindowHandle.Handle.IsNull)

System\Windows\Forms\Controls\WebBrowser\WebBrowser.cs (1)

1105return !hwndFocus.IsNull && PInvoke.IsChild(this, hwndFocus);

System\Windows\Forms\Controls\WebBrowser\WebBrowserSiteBase.cs (1)

192if (!hwnd.IsNull)

System\Windows\Forms\Dialogs\CommonDialogs\FileDialog.cs (1)

565if (!_dialogHWnd.IsNull)

System\Windows\Forms\Dialogs\TaskDialog\TaskDialog.cs (1)

917bool isFirstNotification = _handle.IsNull;

System\Windows\Forms\Form.cs (4)

3415if (icon is not null && !TaskbarOwner.Handle.IsNull) 3914if (!ownerHandle.IsNull) 3970desktop = !hWndOwner.IsNull ? Screen.FromHandle(hWndOwner) : Screen.FromPoint(MousePosition); 5726if (!captureHwnd.IsNull)

System\Windows\Forms\Internal\WinFormsUtils.cs (1)

155if (hwnd.IsNull)

System\Windows\Forms\Layout\Containers\ContainerControl.cs (1)

629if (focusHandle.IsNull || FromChildHandle(focusHandle) != _activeControl)

System\Windows\Forms\NativeWindow.cs (12)

99if (!handle.IsNull) 129if (!HWND.IsNull) 136if (!handle.IsNull && ownedHandle) 238Debug.Assert(!handle.IsNull, "Should never insert a zero handle into the hash"); 299Debug.Assert(!hwnd.IsNull); 409if (!HWND.IsNull) 470if (createResult.IsNull) 531if (!HWND.IsNull) 615if (!handle.IsNull && handle != (HWND)(-1)) 664if (HWND.IsNull) 671if (HWND.IsNull) 704Debug.Assert(!hwnd.IsNull);

System\Windows\Forms\NativeWindow.WindowClass.cs (1)

44Debug.Assert(!hwnd.IsNull, "Windows called us with an HWND of 0");

System\Windows\Forms\OLE\DropSource.cs (1)

93if (!lastHwndTarget.IsNull && (Cursor.Position is Point point))

System\Windows\Forms\Timer.cs (8)

208public bool IsTimerRunning => _timerID != 0 && !HWND.IsNull; 212if (HWND.IsNull) 230Debug.Assert(!HWND.IsNull, "Could not create timer HWND."); 231return !HWND.IsNull; 239if (!hwnd.IsNull) 275if (hwnd.IsNull) 290if (_stoppingTimer || hwnd.IsNull || !PInvoke.IsWindow(hwnd)) 344Debug.Assert(m.HWND == HWND && !HWND.IsNull, "Timer getting messages for other windows?");

System\Windows\Forms\ToolTip\ToolTip.cs (4)

1041if (!hwndControl.IsNull) 1071else if (found.IsNull) 1095if (!hwnd.IsNull) 1534if (!hwnd.IsNull)

System\Windows\Forms\UserControl.cs (1)

249if (hwndFocus.IsNull)

System\Windows\Forms\VisualStyles\VisualStyleRenderer.cs (3)

226if (!hwnd.IsNull) 253if (!hwnd.IsNull) 584if (!hwnd.IsNull && ScaleHelper.IsThreadPerMonitorV2Aware)

System\Windows\Forms\WindowSubclassHandler.cs (1)

63if (hwnd.IsNull)

System\ComponentModel\Design\DesignerActionPanel.EditorPropertyLine.FlyoutDialog.cs (3)

108while (!hWnd.IsNull) 111if (hWnd.IsNull) 145if (!hWndCapture.IsNull)

System\ComponentModel\Design\DesignerActionUI.DesignerActionToolStripDropDown.cs (2)

201while (!hWndDescendant.IsNull) 204if (hWndDescendant.IsNull)

System\Drawing\Design\ColorEditor.ColorPalette.cs (1)

257if (!hwndFocus.IsNull)

System\Drawing\Design\FontEditor.cs (1)

48if (!hwndFocus.IsNull)

System\Drawing\Design\IconEditor.cs (1)

84if (!hwndFocus.IsNull)

System\Drawing\Design\ImageEditor.cs (1)

113if (!hwndFocus.IsNull)

System\Windows\Forms\Design\CommandSet.cs (1)

685if (!hwnd.IsNull)

System\Windows\Forms\Design\ControlDesigner.cs (1)

2406while (!hwndChild.IsNull)

System\Windows\Forms\Design\ImageListImageEditor.cs (1)

83if (!hwndFocus.IsNull)

System\Windows\Forms\Design\ListViewDesigner.cs (1)

79if (!hwndHit.IsNull && hwndHit != listView.Handle)