using System;
using System.Runtime.InteropServices;
using static Vanara.PInvoke.User32_Gdi;
// ReSharper disable InconsistentNaming ReSharper disable FieldCanBeMadeReadOnly.Global
namespace Vanara.PInvoke
{
public static partial class ComCtl32
{
public const int CBEN_FIRST = -800;
public const int CBM_FIRST = 0x1700;
public const string WC_COMBOBOXEX = "ComboBoxEx32";
/// A value that specifies the action that generated the CBEN_ENDEDIT notification code.
[PInvokeData("Commctrl.h", MSDNShortId = "bb775750")]
public enum CBEN_ENDEDIT_FLAG
{
/// The edit box lost the keyboard focus.
CBENF_KILLFOCUS = 1,
/// The user completed the edit operation by pressing ENTER.
CBENF_RETURN = 2,
/// The user pressed ESC.
CBENF_ESCAPE = 3,
/// The user activated the drop-down list.
CBENF_DROPDOWN = 4,
}
///
/// A set of bit flags that specify attributes of COMBOBOXEXITEM or of an operation that is using this structure. The flags specify members that are
/// valid or must be filled in.
///
[PInvokeData("Commctrl.h", MSDNShortId = "bb775746")]
[Flags]
public enum ComboBoxExItemMask
{
/// The pszText member is valid or must be filled in.
CBEIF_TEXT = 0x00000001,
/// The iImage member is valid or must be filled in.
CBEIF_IMAGE = 0x00000002,
/// The iSelectedImage member is valid or must be filled in.
CBEIF_SELECTEDIMAGE = 0x00000004,
/// The iOverlay member is valid or must be filled in.
CBEIF_OVERLAY = 0x00000008,
/// The iIndent member is valid or must be filled in.
CBEIF_INDENT = 0x00000010,
/// The lParam member is valid or must be filled in.
CBEIF_LPARAM = 0x00000020,
///
/// Set this flag when processing CBEN_GETDISPINFO; the ComboBoxEx control will retain the supplied information and will not request it again.
///
CBEIF_DI_SETITEM = 0x10000000,
}
/// Support the extended styles that are listed in this section as well as most standard combo box control styles.
[PInvokeData("Commctrl.h", MSDNShortId = "bb775742")]
public enum ComboBoxExStyle
{
/// The edit box and the dropdown list will not display item images.
CBES_EX_NOEDITIMAGE = 0x00000001,
/// The edit box and the dropdown list will not display item images.
CBES_EX_NOEDITIMAGEINDENT = 0x00000002,
///
/// Windows NT only. The edit box will use the slash (/), backslash (\), and period (.) characters as word delimiters. This makes keyboard shortcuts
/// for word-by-word cursor movement effective in path names and URLs.
///
CBES_EX_PATHWORDBREAKPROC = 0x00000004,
///
/// Allows the ComboBoxEx control to be vertically sized smaller than its contained combo box control. If the ComboBoxEx is sized smaller than the
/// combo box, the combo box will be clipped.
///
CBES_EX_NOSIZELIMIT = 0x00000008,
///
/// BSTR searches in the list will be case sensitive. This includes searches as a result of text being typed in the edit box and the
/// CB_FINDSTRINGEXACT message.
///
CBES_EX_CASESENSITIVE = 0x00000010,
///
/// Windows Vista and later. Causes items in the drop-down list and the edit box (when the edit box is read only) to be truncated with an ellipsis
/// ("...") rather than just clipped by the edge of the control. This is useful when the control needs to be set to a fixed width, yet the entries in
/// the list may be long.
///
CBES_EX_TEXTENDELLIPSIS = 0x00000020,
}
/// Contains combo box status information.
[PInvokeData("Winuser.h", MSDNShortId = "bb775798")]
[Flags]
public enum ComboBoxInfoState
{
/// The button exists and is not pressed.
None = 0,
/// There is no button.
STATE_SYSTEM_INVISIBLE = 0x00008000,
/// The button is pressed.
STATE_SYSTEM_PRESSED = 0x00000008
}
public enum ComboBoxMessage
{
CB_GETEDITSEL = 0x0140,
CB_LIMITTEXT = 0x0141,
CB_SETEDITSEL = 0x0142,
CB_ADDSTRING = 0x0143,
CB_DELETESTRING = 0x0144,
CB_DIR = 0x0145,
CB_GETCOUNT = 0x0146,
CB_GETCURSEL = 0x0147,
CB_GETLBTEXT = 0x0148,
CB_GETLBTEXTLEN = 0x0149,
CB_INSERTSTRING = 0x014A,
CB_RESETCONTENT = 0x014B,
CB_FINDSTRING = 0x014C,
CB_SELECTSTRING = 0x014D,
CB_SETCURSEL = 0x014E,
CB_SHOWDROPDOWN = 0x014F,
CB_GETITEMDATA = 0x0150,
CB_SETITEMDATA = 0x0151,
CB_GETDROPPEDCONTROLRECT = 0x0152,
CB_SETITEMHEIGHT = 0x0153,
CB_GETITEMHEIGHT = 0x0154,
CB_SETEXTENDEDUI = 0x0155,
CB_GETEXTENDEDUI = 0x0156,
CB_GETDROPPEDSTATE = 0x0157,
CB_FINDSTRINGEXACT = 0x0158,
CB_SETLOCALE = 0x0159,
CB_GETLOCALE = 0x015A,
CB_GETTOPINDEX = 0x015b,
CB_SETTOPINDEX = 0x015c,
CB_GETHORIZONTALEXTENT = 0x015d,
CB_SETHORIZONTALEXTENT = 0x015e,
CB_GETDROPPEDWIDTH = 0x015f,
CB_SETDROPPEDWIDTH = 0x0160,
CB_INITSTORAGE = 0x0161,
CB_MULTIPLEADDSTRING = 0x0163,
CB_GETCOMBOBOXINFO = 0x0164,
CB_SETMINVISIBLE = CBM_FIRST + 1,
CB_GETMINVISIBLE = CBM_FIRST + 2,
CB_SETCUEBANNER = CBM_FIRST + 3,
CB_GETCUEBANNER = CBM_FIRST + 4,
CBEM_SETIMAGELIST = WindowMessage.WM_USER + 2,
CBEM_GETIMAGELIST = WindowMessage.WM_USER + 3,
CBEM_DELETEITEM = ComboBoxMessage.CB_DELETESTRING,
CBEM_GETCOMBOCONTROL = WindowMessage.WM_USER + 6,
CBEM_GETEDITCONTROL = WindowMessage.WM_USER + 7,
CBEM_SETEXSTYLE = WindowMessage.WM_USER + 8, // use SETEXTENDEDSTYLE instead
CBEM_SETEXTENDEDSTYLE = WindowMessage.WM_USER + 14, // lparam == new style, wParam (optional) == mask
CBEM_GETEXSTYLE = WindowMessage.WM_USER + 9, // use GETEXTENDEDSTYLE instead
CBEM_GETEXTENDEDSTYLE = WindowMessage.WM_USER + 9,
CBEM_SETUNICODEFORMAT = CommonControlMessage.CCM_SETUNICODEFORMAT,
CBEM_GETUNICODEFORMAT = CommonControlMessage.CCM_GETUNICODEFORMAT,
CBEM_HASEDITCHANGED = WindowMessage.WM_USER + 10,
CBEM_INSERTITEM = WindowMessage.WM_USER + 11,
CBEM_SETITEM = WindowMessage.WM_USER + 12,
CBEM_GETITEM = WindowMessage.WM_USER + 13,
CBEM_SETWINDOWTHEME = CommonControlMessage.CCM_SETWINDOWTHEME,
}
/// Combo Box Notification Codes
[PInvokeData("Winuser.h", MSDNShortId = "ff485902")]
public enum ComboBoxNotification
{
///
/// Sent when a combo box cannot allocate enough memory to meet a specific request. The parent window of the combo box receives this notification
/// code through the WM_COMMAND message.
///
/// -
/// wParam
/// The LOWORD contains the control identifier of the combo box. The HIWORD specifies the notification code.
///
/// -
/// lParam
/// Handle to the combo box.
///
///
///
CBN_ERRSPACE = (-1),
///
/// Sent when the user changes the current selection in the list box of a combo box. The user can change the selection by clicking in the list box or
/// by using the arrow keys. The parent window of the combo box receives this notification code in the form of a WM_COMMAND message.
///
/// -
/// wParam
/// The LOWORD contains the control identifier of the combo box. The HIWORD specifies the notification code.
///
/// -
/// lParam
/// Handle to the combo box.
///
///
///
CBN_SELCHANGE = 1,
///
/// Sent when the user double-clicks a string in the list box of a combo box. The parent window of the combo box receives this notification code
/// through the WM_COMMAND message.
///
/// -
/// wParam
/// The LOWORD contains the control identifier of the combo box. The HIWORD specifies the notification code.
///
/// -
/// lParam
/// Handle to the combo box.
///
///
///
CBN_DBLCLK = 2,
///
/// Sent when a combo box receives the keyboard focus. The parent window of the combo box receives this notification code through the WM_COMMAND message.
///
/// -
/// wParam
/// The LOWORD contains the control identifier of the combo box. The HIWORD specifies the notification code.
///
/// -
/// lParam
/// Handle to the combo box.
///
///
///
CBN_SETFOCUS = 3,
///
/// Sent when a combo box loses the keyboard focus. The parent window of the combo box receives this notification code through the WM_COMMAND message.
///
/// -
/// wParam
/// The LOWORD contains the control identifier of the combo box. The HIWORD specifies the notification code.
///
/// -
/// lParam
/// Handle to the combo box.
///
///
///
CBN_KILLFOCUS = 4,
///
/// Sent after the user has taken an action that may have altered the text in the edit control portion of a combo box. Unlike the CBN_EDITUPDATE
/// notification code, this notification code is sent after the system updates the screen. The parent window of the combo box receives this
/// notification code through the WM_COMMAND message.
///
/// -
/// wParam
/// The LOWORD contains the control identifier of the combo box. The HIWORD specifies the notification code.
///
/// -
/// lParam
/// Handle to the combo box.
///
///
///
CBN_EDITCHANGE = 5,
///
/// Sent when the edit control portion of a combo box is about to display altered text. This notification code is sent after the control has
/// formatted the text, but before it displays the text. The parent window of the combo box receives this notification code through the WM_COMMAND message.
///
/// -
/// wParam
/// The LOWORD contains the control identifier of the combo box. The HIWORD specifies the notification code.
///
/// -
/// lParam
/// Handle to the combo box.
///
///
///
CBN_EDITUPDATE = 6,
///
/// Sent when the list box of a combo box is about to be made visible. The parent window of the combo box receives this notification code through the
/// WM_COMMAND message.
///
/// -
/// wParam
/// The LOWORD contains the control identifier of the combo box. The HIWORD specifies the notification code.
///
/// -
/// lParam
/// Handle to the combo box.
///
///
///
CBN_DROPDOWN = 7,
///
/// Sent when the list box of a combo box has been closed. The parent window of the combo box receives this notification code through the WM_COMMAND message.
///
/// -
/// wParam
/// The LOWORD contains the control identifier of the combo box. The HIWORD specifies the notification code.
///
/// -
/// lParam
/// Handle to the combo box.
///
///
///
CBN_CLOSEUP = 8,
///
/// Sent when the user selects a list item, or selects an item and then closes the list. It indicates that the user's selection is to be processed.
/// The parent window of the combo box receives this notification code through the WM_COMMAND message.
///
/// -
/// wParam
/// The LOWORD contains the control identifier of the combo box. The HIWORD specifies the notification code.
///
/// -
/// lParam
/// Handle to the combo box.
///
///
///
CBN_SELENDOK = 9,
///
/// Sent when the user selects an item, but then selects another control or closes the dialog box. It indicates the user's initial selection is to be
/// ignored. The parent window of the combo box receives this notification code through the WM_COMMAND message.
///
/// -
/// wParam
/// The LOWORD contains the control identifier of the combo box. The HIWORD specifies the notification code.
///
/// -
/// lParam
/// Handle to the combo box.
///
///
///
CBN_SELENDCANCEL = 10,
///
/// Sent when a new item has been inserted in the control. This notification code is sent in the form of a WM_NOTIFY message.
///
/// -
/// lParam
///
/// A pointer to an structure containing information about the notification code and the item that was inserted.
///
///
///
///
CBEN_INSERTITEM = CBEN_FIRST - 1,
///
/// Sent when an item has been deleted. This notification code is sent in the form of a WM_NOTIFY message.
///
/// -
/// lParam
///
/// A pointer to an structure that contains information about the notification code and the deleted item.
///
///
///
///
CBEN_DELETEITEM = CBEN_FIRST - 2,
///
/// Sent when the user activates the drop-down list or clicks in the control's edit box. This notification code is sent in the form of a WM_NOTIFY message.
///
/// -
/// lParam
/// A pointer to an structure that contains information about the notification code.
///
///
///
CBEN_BEGINEDIT = CBEN_FIRST - 4,
///
/// Sent when the user has concluded an operation within the edit box or has selected an item from the control's drop-down list. This notification
/// code is sent in the form of a WM_NOTIFY message.
///
/// -
/// lParam
/// A pointer to an structure that contains information about how the user concluded the edit operation.
///
///
///
CBEN_ENDEDITA = CBEN_FIRST - 5,
///
/// Sent when the user has concluded an operation within the edit box or has selected an item from the control's drop-down list. This notification
/// code is sent in the form of a WM_NOTIFY message.
///
/// -
/// lParam
/// A pointer to an structure that contains information about how the user concluded the edit operation.
///
///
///
CBEN_ENDEDITW = CBEN_FIRST - 6,
///
/// Sent to retrieve display information about a callback item. This notification code is sent in the form of a WM_NOTIFY message.
///
/// -
/// lParam
/// A pointer to an structure that contains information about the notification code.
///
///
///
CBEN_GETDISPINFO = CBEN_FIRST - 7,
///
/// Sent when the user begins dragging the image of the item displayed in the edit portion of the control. This notification code is sent in the form
/// of a WM_NOTIFY message.
///
/// -
/// lParam
/// A pointer to a structure that contains information about the notification code.
///
///
///
CBEN_DRAGBEGIN = CBEN_FIRST - 9,
}
///
/// To create a combo box using the CreateWindow or CreateWindowEx function, specify the COMBOBOX class, appropriate window style constants, and a
/// combination of the following combo box styles.
///
[PInvokeData("CommCtrl.h", MSDNShortId = "bb775796")]
public enum ComboBoxStyle
{
/// Displays the list box at all times. The current selection in the list box is displayed in the edit control.
CBS_SIMPLE = 0x0001,
/// Similar to CBS_SIMPLE, except that the list box is not displayed unless the user selects an icon next to the edit control.
CBS_DROPDOWN = 0x0002,
///
/// Similar to CBS_DROPDOWN, except that the edit control is replaced by a static text item that displays the current selection in the list box.
///
CBS_DROPDOWNLIST = 0x0003,
///
/// Specifies that the owner of the list box is responsible for drawing its contents and that the items in the list box are all the same height. The
/// owner window receives a WM_MEASUREITEM message when the combo box is created and a WM_DRAWITEM message when a visual aspect of the combo box has changed.
///
CBS_OWNERDRAWFIXED = 0x0010,
///
/// Specifies that the owner of the list box is responsible for drawing its contents and that the items in the list box are variable in height. The
/// owner window receives a WM_MEASUREITEM message for each item in the combo box when you create the combo box and a WM_DRAWITEM message when a
/// visual aspect of the combo box has changed.
///
CBS_OWNERDRAWVARIABLE = 0x0020,
///
/// Automatically scrolls the text in an edit control to the right when the user types a character at the end of the line. If this style is not set,
/// only text that fits within the rectangular boundary is allowed.
///
CBS_AUTOHSCROLL = 0x0040,
///
/// Converts text entered in the combo box edit control from the Windows character set to the OEM character set and then back to the Windows
/// character set. This ensures proper character conversion when the application calls the CharToOem function to convert a Windows string in the
/// combo box to OEM characters. This style is most useful for combo boxes that contain file names and applies only to combo boxes created with the
/// CBS_SIMPLE or CBS_DROPDOWN style.
///
CBS_OEMCONVERT = 0x0080,
/// Automatically sorts strings added to the list box.
CBS_SORT = 0x0100,
///
/// Specifies that an owner-drawn combo box contains items consisting of strings. The combo box maintains the memory and address for the strings so
/// the application can use the CB_GETLBTEXT message to retrieve the text for a particular item.
///
CBS_HASSTRINGS = 0x0200,
///
/// Specifies that the size of the combo box is exactly the size specified by the application when it created the combo box. Normally, the system
/// sizes a combo box so that it does not display partial items.
///
CBS_NOINTEGRALHEIGHT = 0x0400,
///
/// Shows a disabled vertical scroll bar in the list box when the box does not contain enough items to scroll. Without this style, the scroll bar is
/// hidden when the list box does not contain enough items.
///
CBS_DISABLENOSCROLL = 0x0800,
/// Converts to uppercase all text in both the selection field and the list.
CBS_UPPERCASE = 0x2000,
/// Converts to lowercase all text in both the selection field and the list.
CBS_LOWERCASE = 0x4000,
}
///
/// Sends the specified message to a window or windows. The SendMessage function calls the window procedure for the specified window and does not return
/// until the window procedure has processed the message.
///
///
/// A handle to the window whose window procedure will receive the message. If this parameter is HWND_BROADCAST ((HWND)0xffff), the message is sent to
/// all top-level windows in the system, including disabled or invisible unowned windows, overlapped windows, and pop-up windows; but the message is not
/// sent to child windows.
///
/// The message to be sent.
/// Additional message-specific information.
/// Additional message-specific information.
/// The return value specifies the result of the message processing; it depends on the message sent.
public static IntPtr SendMessage(HandleRef hWnd, ComboBoxMessage Msg, int wParam, ref COMBOBOXINFO item) => User32_Gdi.SendMessage(hWnd, Msg, wParam, ref item);
/// Contains combo box status information.
[PInvokeData("Winuser.h", MSDNShortId = "bb775798")]
[StructLayout(LayoutKind.Sequential)]
public struct COMBOBOXINFO
{
/// The size, in bytes, of the structure. The calling application must set this to sizeof(COMBOBOXINFO).
public int cbSize;
/// A RECT structure that specifies the coordinates of the edit box.
public RECT rcItem;
/// A RECT structure that specifies the coordinates of the button that contains the drop-down arrow.
public RECT rcButton;
/// The combo box button state.
public ComboBoxInfoState buttonState;
/// A handle to the combo box.
public IntPtr hwndCombo;
/// A handle to the edit box.
public IntPtr hwndEdit;
/// A handle to the drop-down list.
public IntPtr hwndList;
/// Creates an instance of the structure from a handle and retrieves its values.
/// The handle to a ComboBox.
/// A structure with values from the supplied handle.
[System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.LinkDemand, Flags = System.Security.Permissions.SecurityPermissionFlag.UnmanagedCode)]
public static COMBOBOXINFO FromHandle(HandleRef hComboBox)
{
if (hComboBox.Handle == IntPtr.Zero)
throw new ArgumentException("ComboBox handle cannot be NULL.", nameof(hComboBox));
var cbi = new COMBOBOXINFO() { cbSize = Marshal.SizeOf(typeof(COMBOBOXINFO)) };
SendMessage(hComboBox, ComboBoxMessage.CB_GETCOMBOBOXINFO, 0, ref cbi);
return cbi;
}
/// Gets a value indicating whether this is invisible.
/// true if invisible; otherwise, false.
public bool Invisible => (buttonState & ComboBoxInfoState.STATE_SYSTEM_INVISIBLE) == ComboBoxInfoState.STATE_SYSTEM_INVISIBLE;
/// Gets a value indicating whether this is pressed.
/// true if pressed; otherwise, false.
public bool Pressed => (buttonState & ComboBoxInfoState.STATE_SYSTEM_PRESSED) == ComboBoxInfoState.STATE_SYSTEM_PRESSED;
/// Gets the item rectangle.
/// The item rectangle.
public System.Drawing.Rectangle ItemRectangle => rcItem;
/// Gets the button rectangle.
/// The button rectangle.
public System.Drawing.Rectangle ButtonRectangle => rcButton;
}
/// Contains information used with the CBEN_DRAGBEGIN notification code.
[PInvokeData("Commctrl.h", MSDNShortId = "bb775748")]
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct NMCBEDRAGBEGIN
{
/// The NMHDR structure that contains information about the notification code.
public NMHDR hdr;
///
/// The zero-based index of the item being dragged. This value will always be -1, indicating that the item being dragged is the item displayed in the
/// edit portion of the control.
///
public int iItemId;
/// The character buffer that contains the text of the item being dragged.
public string szText;
}
///
/// Contains information about the conclusion of an edit operation within a ComboBoxEx control. This structure is used with the CBEN_ENDEDIT notification code.
///
[PInvokeData("Commctrl.h", MSDNShortId = "bb775750")]
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct NMCBEENDEDIT
{
/// The NMHDR structure that contains information about the notification code.
public NMHDR hdr;
///
/// A value indicating whether the contents of the control's edit box have changed. This value is nonzero if the contents have been modified, or zero otherwise.
///
[MarshalAs(UnmanagedType.Bool)] public bool fChanged;
///
/// The zero-based index of the item that will be selected after completing the edit operation. This value can be CB_ERR if no item will be selected.
///
public int iNewSelection;
/// A zero-terminated string that contains the text from within the control's edit box.
public string szText;
/// A value that specifies the action that generated the CBEN_ENDEDIT notification code.
public CBEN_ENDEDIT_FLAG iWhy;
}
/// Contains information specific to ComboBoxEx items for use with notification codes.
[PInvokeData("Commctrl.h", MSDNShortId = "bb775752")]
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct NMCOMBOBOXEX
{
/// The NMHDR structure that contains information about the notification code.
public NMHDR hdr;
///
/// The COMBOBOXEXITEM structure that holds item information specific to the current notification. Upon receiving a notification code, the
/// COMBOBOXEXITEM structure holds information required for the owner to respond. The members of this structure are often used as fields for the
/// owner to return values in response to the notification.
///
public COMBOBOXEXITEM ceItem;
}
/// Contains information about an item in a ComboBoxEx control.
///
[PInvokeData("Commctrl.h", MSDNShortId = "bb775746")]
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public sealed class COMBOBOXEXITEM : IDisposable
{
///
/// A set of bit flags that specify attributes of this structure or of an operation that is using this structure. The flags specify members that are
/// valid or must be filled in.
///
public ComboBoxExItemMask mask;
/// The zero-based index of the item.
[MarshalAs(UnmanagedType.SysInt)] public int iItem;
///
/// A pointer to a character buffer that contains or receives the item's text. If text information is being retrieved, this member must be set to the
/// address of a character buffer that will receive the text. The size of this buffer must also be indicated in cchTextMax. If this member is set to
/// LPSTR_TEXTCALLBACK, the control will request the information by using the CBEN_GETDISPINFO notification codes.
///
public IntPtr pszText;
/// The length of pszText, in TCHARs. If text information is being set, this member is ignored.
public int cchTextMax;
///
/// The zero-based index of an image within the image list. The specified image will be displayed for the item when it is not selected. If this
/// member is set to I_IMAGECALLBACK, the control will request the information by using CBEN_GETDISPINFO notification codes.
///
public int iImage;
///
/// The zero-based index of an image within the image list. The specified image will be displayed for the item when it is selected. If this member is
/// set to I_IMAGECALLBACK, the control will request the information by using CBEN_GETDISPINFO notification codes.
///
public int iSelectedImage;
///
/// The one-based index of an overlay image within the image list. If this member is set to I_IMAGECALLBACK, the control will request the information
/// by using CBEN_GETDISPINFO notification codes.
///
public int iOverlay;
///
/// The number of indent spaces to display for the item. Each indentation equals 10 pixels. If this member is set to I_INDENTCALLBACK, the control
/// will request the information by using CBEN_GETDISPINFO notification codes.
///
public int iIndent;
/// A value specific to the item.
public IntPtr lParam;
/// Initializes a new instance of the class.
/// Size of the text buffer. If this value is 0, no buffer is created.
public COMBOBOXEXITEM(int textBufferSize = 0) : this(textBufferSize == 0 ? null : new string('\0', textBufferSize)) { }
/// Initializes a new instance of the class.
/// The text.
public COMBOBOXEXITEM(string text) { Text = text; }
/// Gets or sets the item's text.
/// The text value.
public string Text
{
get => pszText == LPSTR_TEXTCALLBACK ? null : Marshal.PtrToStringAuto(pszText);
set
{
((IDisposable)this).Dispose();
if (value == null) return;
pszText = Marshal.StringToCoTaskMemAuto(value);
cchTextMax = value.Length;
mask |= ComboBoxExItemMask.CBEIF_TEXT;
}
}
/// Gets or sets a value indicating whether to use a text callback method.
/// true if using text callback method; otherwise, false.
public bool UseTextCallback
{
get => pszText == LPSTR_TEXTCALLBACK;
set
{
if (value)
{
((IDisposable)this).Dispose();
pszText = LPSTR_TEXTCALLBACK;
}
mask |= ComboBoxExItemMask.CBEIF_TEXT;
}
}
/// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
void IDisposable.Dispose()
{
if (pszText != IntPtr.Zero && pszText != LPSTR_TEXTCALLBACK)
{
Marshal.FreeCoTaskMem(pszText);
pszText = IntPtr.Zero;
cchTextMax = 0;
}
}
}
}
}