c++ - 我如何处理更改插入符位置的事件？

Question

我需要处理在编辑控件(而不是 richedit 控件)中更改插入符号位置的事件。

我知道如何处理在编辑中更改文本的事件，但我不知道如何处理在编辑控件中更改插入符号位置的事件。

我希望有人能帮助我。感谢大家。

Answer 1

完成此操作后，我通过子类化编辑控件 (SetWindowLongPtr) 并向父窗口发送可能会移动插入符号的消息来在状态栏上显示行号。

#define CARET_MOVED_COMMAND_ID    50001

WNDPROC OriginalEditProc = 0;
HWND OriginalEditParent = 0;

LRESULT WINAPI MyEditProc( HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam )
{
    // Handle message by original edit control procedure.
    LRESULT result = CallWindowProc( OriginalEditProc, hwnd, msg, wparam, lparam );

    switch ( msg )
    {
    case WM_CHAR:
    case WM_KEYDOWN:
    case WM_KEYUP:
    case WM_LBUTTONDOWN:
    case WM_LBUTTONUP:
    case WM_LBUTTONDBLCLK:
    case WM_RBUTTONDOWN:
    case WM_RBUTTONUP:
    case WM_RBUTTONDBLCLK:
    case WM_MBUTTONDOWN:
    case WM_MBUTTONUP:
    case WM_MBUTTONDBLCLK:
    case EM_SETSEL:
    // And maybe others...
        // Notify parent of posible caret move.
        // You can recreate EN_SELCHANGE behavior, I have been too lazy
        // and was just sending command (like from menu).
        SendMessage( OriginalEditParent, WM_COMMAND, MAKEWPARAM( CARET_MOVED_COMMAND_ID, 0 ), 0 );
        break;
    }
    return result;
}

// ---- In initialization code ----
// subclass
OriginalEditParent = MyMainWindow;
OriginalEditProc = (WNDPROC) SetWindowLongPtr( EditBoxHwnd, GWLP_WNDPROC, (LONG_PTR)MyEditProc );

// ---- In parent window message handling ----
case WM_COMMAND:
    switch ( LOWORD( wparam ) )
    {
    case CARET_MOVED_COMMAND_ID:
        {
            // You sould execute this code in EN_CHANGE handler,
            // so it can handle cuting, pasting, undo etc.
            int line = (int) SendMessage( EditBoxHwnd, EM_LINEFROMCHAR, -1, 0 );
            // Update status bar. Could be optimized by remembering
            // displayed line number and updating only when it changes.
            wchar_t buff[50];
            wsprintf( buff, L"%d", line );
            SendMessage( StatusBarHwnd, SB_SETTEXT, MAKEWPARAM( 1, SBT_NOBORDERS ), (LPARAM) buff );
        }
        break;
    }
    break;