Question

I have code as below, and my question is why in the cell A[0][0] setWindowText put nothing?

if(LOWORD( wParam ) == 104){
    int td;
    int td_width=80;
    int tr = 0;
    int tr_height=20; 

    for (tr=0;tr<2;tr++) {
        for (td=0;td<10;td++) {
            HWND A[tr][td];

            A[tr][td] = CreateWindowEx( 0, "EDIT", NULL, WS_CHILD | WS_VISIBLE | WS_BORDER | ES_MULTILINE | ES_AUTOVSCROLL,
td*td_width, tr*tr_height+50, td_width+1, tr_height+1, hwnd, NULL, hInstance, NULL );
        }
        SetWindowText(A[0][0], "MK" );
    }

}

Answer 1

As Peter said, you are declaring your array in the wrong spot. But more than that, you are also declaring the array as fixed-length but using run-time values to specify its bounds. That will not work, and should not even compile. A fixed-length array’s bounds must be known at compile-time, not at run-time.

Try this instead:

if (LOWORD(wParam) == 104)
{
    const int td_width = 80;
    const int tr_height = 20; 

    HWND A[2][10];

    for (int tr = 0; tr < 2; ++tr)
    {
        for (int td = 0; td < 10; ++td)
        {
            A[tr][td] = CreateWindowEx( 0, TEXT("EDIT"), NULL, WS_CHILD | WS_VISIBLE | WS_BORDER | ES_MULTILINE | ES_AUTOVSCROLL, td*td_width, tr*tr_height+50, td_width+1, tr_height+1, hwnd, NULL, hInstance, NULL );
        }
    }

    SetWindowText(A[0][0], TEXT("MK") );
}