Create dynamic buttons while reading from SQL Server

Question

I'm using this code while reading from SQL Server. The problem is that it runs the loop as many times are my SQL Server results.

SqlCommand sqlCmd = new SqlCommand("Select Name from TablesDesigner", con);

SqlDataReader sqlReader = sqlCmd.ExecuteReader();

while (sqlReader.Read())
{
    for (int row = 0; row < NUM_ROWS; row++)
    {
        TableRow tablerow = new TableRow(this);

        TableLayout.LayoutParams linearLayoutParams = new TableLayout.LayoutParams(TableLayout.LayoutParams.MatchParent, TableLayout.LayoutParams.MatchParent, 1.0f);
        tablerow.LayoutParameters = linearLayoutParams;
        table.AddView(tablerow);

        for (int col = 0; col < NUM_COLS; col++)
        {
            int FINAL_COL = col;
            int FINAL_ROW = row;

            Button btn = new Button(this);
            TableRow.LayoutParams linearLayoutParams2 = new TableRow.LayoutParams(TableRow.LayoutParams.MatchParent, TableRow.LayoutParams.MatchParent, 1.0f);
            btn.LayoutParameters = linearLayoutParams2;
            btn.Text = sqlReader["Name"].ToString();
            tablerow.AddView(btn);
        }
    }
}

My result is below:

And my desired result is:

Where should I place my loop for getting the desired result? Or should I break it somehow?

Thanks.

Also what if I want to use two rows??

The inner loop with `col` variable is executing upto `NUM_COLS` for each iteration of `row` variable. You may use only one loop here. — shahsani, Oct 17 '17 at 00:25

John Wu · Answer 1 · 2017-10-17T01:34:01.397

When confronted with a difficult problem, break it down into manageable bits (this is good coding practice anyway).

First, get the data you need into a single list. Don't forget to Dispose your DataReader.

public List<string> GetButtonNames()
{
    var buttonNames = new List<string>();
    SqlCommand sqlCmd = new SqlCommand("Select Name from TablesDesigner", con);
    using (var sqlReader = sqlCmd.ExecuteReader())
    {
        while (sqlReader.Read())
        {
            buttonNames.Add(sqlReader["Name"].ToString());
        }
    }
    return buttonNames;
}

Then write a function to organize it into a 2D list. I stole the logic for this from this question.

public static List<List<string>> Make2DList(List<string> input, int width=4)  
{        
    var output = new List<List<string>>(); 

    for (int i=0; i < input.Count; i+= width) 
    { 
        output.Add(input.GetRange(i, Math.Min(width, input.Count - i))); 
    } 

    return output; 
}

Now you have a list of lists. The "outer" list corresponds to each table row. The inner list is a list of column values within that row.

Now all you need is code to make it into a table. Because we organized the data into a grid already, we can use normal foreach syntax which makes it very easy.

public void RenderButtonTable(List<List<string>> names)
{
    var layout = new TableLayout.LayoutParams
        (
            TableLayout.LayoutParams.MatchParent,
            TableLayout.LayoutParams.MatchParent, 
            1.0f
        );
    tablerow.LayoutParameters = layout;

    foreach (var row in names)
    {
        TableRow tablerow = new TableRow(this);
        tablerow.LayoutParameters = layout;
        table.AddView(tablerow);
        foreach (var col in row)
        {
            Button btn = new Button(this);
            btn.Text = col;
            tablerow.AddView(btn);
        }
    }
}

Put it all together:

void CreateDynamicButtonsWhileReadingFromSQLServer()
{
    var buttonNames = GetButtonNames();
    var gridData = Make2DList(buttonNames, NUM_COLS);
    RenderButtonTable(gridData);
}

Thank you very much it works exellent!!! But where should i place a btn.Click += (sender, e) => { Toast.MakeText(this, btn.Text, ToastLength.Short); }; For taking Button click name? — dSaos, Oct 17 '17 at 08:18
[Link](https://stackoverflow.com/questions/6187944/how-can-i-create-a-dynamic-button-click-event-on-a-dynamic-button) — John Wu, Oct 17 '17 at 09:46

Create dynamic buttons while reading from SQL Server

1 Answers1