Using the Flexgrid in VC++

Introduction

When I had to use the flexgrid for the first time, I was too frustrated to find out that no proper documentation existed on the net. The ones available were too complicated for me to understand. And the ones that were easy were in VB. This article is to help persons who are going to use the flexgrid in their applications using VC++. Also take a look at the Warning note at the end of this article.

Implementation

Step 1

First, include the msflexgrid control in the project. To do that :-

1. In the VC++ IDE Menu, go to Project->Add To Project->Components and Controls menu.
2. Then , in the dialog box that appears, select Registered ActiveX Controls. There, You can see a control named "Microsoft Hierarchical FlexGrid Control...".
3. Select that and add it to your project using the Insert button. You can now see the FlexGrid control in the resource editor's CONTROLS toolbar.
4. Add it to your dialog as you add a control usually.

Step 2

Then, set the properties as you want it to be. Right click on the grid and select the Properties option. Change the settings there as per your requirements.

Step 3

Add a member variable for that grid. E.g. m_Grid. The sample given below is for an example. Use it as a guideline to make your application.

Step 4

Its better to clear the flexgrid before you do any operations on it. To do that, use :-

m_Grid.Clear();

Step 5

To add records to the Grid, use something like this.

CString strName,strRemarks;

m_nCount = 0;

// Clear and refresh the grid   

m_Grid.Clear();
m_Grid.Refresh();

// Get the value for strName from the database here 

// Get the strRemarks from the database here


m_nCols = m_Grid.GetCols();
m_Grid.SetTextArray(0, "Name " );      // First  Column

m_Grid.SetTextArray(1, "Remarks " );   // Second  Column


m_nCount++;

// Fill First Column 

m_Grid.SetTextArray(  m_nCols * m_nCount + 0,strName );      
// Fill Second  Column

m_Grid.SetTextArray(  m_nCols * m_nCount + 1, strRemarks );  

// Redraw the grid

m_Grid.SetRedraw(TRUE);
m_Grid.Refresh();

Step 6

To retrieve data from the Grid when the user double clicks on a record, add a double click message handler for the grid using the class wizard. Assuming that you have named the function as OnDblClickGrid, then :-

void YourDialog::OnDblClickGrid()
{
    // Get the current row and column

    int nRow = m_Grid.GetRow();
    int nCol = m_Grid.GetCol();

    CString strName,strRemarks;

    // Get data from the First Column

    strName    =  m_Grid.GetTextMatrix(nRow,nCol+0);    
    // Get data from the Second Column

    strRemarks =  m_Grid.GetTextMatrix(nRow,nCol+1);    
}

Step 7

To move to the previous record, do this :-

void YourDialog::OnBtnPrevious()
{
    m_Grid.SetRedraw(FALSE);

    // Get the current selection


    int NextRow = m_Grid.GetRowSel();

    // If the position is at the last record, return

    if(NextRow <= 1)
    {
        return;
    }
    else
    {
        long BackColor[2],FontColor[2];

        int Column;

        // The BackColor and the FontColor variables 

        // are manipulated because we want a 

        // selected effect to be given to the previous

        // record. Here, we are merely changing 

        // the color of the selected

        // row to give it that effect.


        BackColor[0] = 0x00FFFFFF;
        BackColor[1] = 0x00FFFFB0;

        FontColor[0] = 0x00400000;
        FontColor[1] = 0x000000FF;

        for(Column = 1; Column < m_Grid.GetCols(); Column++)
        {
            m_Grid.SetCol(Column);
            m_Grid.SetCellBackColor(BackColor[0]);
            m_Grid.SetCellForeColor(FontColor[0]);
        }


        m_Grid.SetRow(--NextRow);

        for(Column = 1; Column < m_Grid.GetCols(); Column++)
        {
            m_Grid.SetCol(Column);
            m_Grid.SetCellBackColor(BackColor[1]);
            m_Grid.SetCellForeColor(FontColor[1]);
        }

        m_Grid.Refresh();
        m_Grid.SetRedraw(TRUE);
    }
}

Step 8

To got to the Next record, do the reverse of the code above. Instead of m_Grid.SetRow(--NextRow) it would be m_Grid.SetRow(++NextRow).

Warning

Whenever you use a flexgrid in your application, you have to be twice as careful. Be sure to take regular backups. Sometimes, you might note that your compilation time is too longer than usual. It would be more and more slow with each build. If you feel so, check the size of your .rc file. If its size is abnormal ( I cant specify a size because it depends on your project and its resource contents ),then delete the flexgrid from your application , Close Visual Studio and copy the .rc file from your backup. Open your project again. That should solve your problem. I'm not sure why this happens, maybe its a bug in flexgrid that corrupts or damages it. But from your side, be careful.

Conclusion

The flexgrid is a very easy control to use. But whenever you use it , repeat the mantra "take backups of your .rc file regularly" until it becomes a habit. That's it. All luck and have a great time.