Winforms TableLayoutPanel adding rows programmatically

I just did this last week. Set the GrowStyle on the TableLayoutPanel to AddRows or AddColumns, then your code should work:

// Adds "myControl" to the first column of each row
myTableLayoutPanel.Controls.Add(myControl1, 0 /* Column Index */, 0 /* Row index */);
myTableLayoutPanel.Controls.Add(myControl2, 0 /* Column Index */, 1 /* Row index */);
myTableLayoutPanel.Controls.Add(myControl3, 0 /* Column Index */, 2 /* Row index */);

Here is some working code that seems similar to what you are doing:

    private Int32 tlpRowCount = 0;

    private void BindAddress()
    {
        Addlabel(Addresses.Street);
        if (!String.IsNullOrEmpty(Addresses.Street2))
        {
            Addlabel(Addresses.Street2);
        }
        Addlabel(Addresses.CityStateZip);
        if (!String.IsNullOrEmpty(Account.Country))
        {
            Addlabel(Address.Country);
        }
        Addlabel(String.Empty); // Notice the empty label...
    }

    private void Addlabel(String text)
    {            
        label = new Label();
        label.Dock = DockStyle.Fill;
        label.Text = text;
        label.TextAlign = System.Drawing.ContentAlignment.MiddleLeft;
        tlpAddress.Controls.Add(label, 1, tlpRowCount);
        tlpRowCount++;
    }

The TableLayoutPanel always gives me fits with size. In my example above, I'm filing an address card that might grow or shrink depending on the account having an address line two, or a country. Because the last row, or column, of the table layout panel will stretch, I throw the empty label in there to force a new empty row, then everything lines up nicely.

Here is the designer code so you can see the table I start with:

        //
        // tlpAddress
        // 
        this.tlpAddress.AutoSize = true;
        this.tlpAddress.BackColor = System.Drawing.Color.Transparent;
        this.tlpAddress.ColumnCount = 2;
        this.tlpAddress.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Absolute, 25F));
        this.tlpAddress.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 100F));
        this.tlpAddress.Controls.Add(this.pictureBox1, 0, 0);
        this.tlpAddress.Dock = System.Windows.Forms.DockStyle.Fill;
        this.tlpAddress.Location = new System.Drawing.Point(0, 0);
        this.tlpAddress.Name = "tlpAddress";
        this.tlpAddress.Padding = new System.Windows.Forms.Padding(3);
        this.tlpAddress.RowCount = 2;
        this.tlpAddress.RowStyles.Add(new System.Windows.Forms.RowStyle());
        this.tlpAddress.RowStyles.Add(new System.Windows.Forms.RowStyle());
        this.tlpAddress.Size = new System.Drawing.Size(220, 95);
        this.tlpAddress.TabIndex = 0;

It's a weird design, but the TableLayoutPanel.RowCount property doesn't reflect the count of the RowStyles collection, and similarly for the ColumnCount property and the ColumnStyles collection.

What I've found I needed in my code was to manually update RowCount/ColumnCount after making changes to RowStyles/ColumnStyles.

Here's an example of code I've used:

    /// <summary>
    /// Add a new row to our grid.
    /// </summary>
    /// The row should autosize to match whatever is placed within.
    /// <returns>Index of new row.</returns>
    public int AddAutoSizeRow()
    {
        Panel.RowStyles.Add(new RowStyle(SizeType.AutoSize));
        Panel.RowCount = Panel.RowStyles.Count;
        mCurrentRow = Panel.RowCount - 1;
        return mCurrentRow;
    }

Other thoughts

I've never used DockStyle.Fill to make a control fill a cell in the Grid; I've done this by setting the Anchors property of the control.
If you're adding a lot of controls, make sure you call SuspendLayout and ResumeLayout around the process, else things will run slow as the entire form is relaid after each control is added.

Here's my code for adding a new row to a two-column TableLayoutColumn:

private void AddRow(Control label, Control value)
{
    int rowIndex = AddTableRow();
    detailTable.Controls.Add(label, LabelColumnIndex, rowIndex);
    if (value != null)
    {
        detailTable.Controls.Add(value, ValueColumnIndex, rowIndex);
    }
}

private int AddTableRow()
{
    int index = detailTable.RowCount++;
    RowStyle style = new RowStyle(SizeType.AutoSize);
    detailTable.RowStyles.Add(style);
    return index;
}

The label control goes in the left column and the value control goes in the right column. The controls are generally of type Label and have their AutoSize property set to true.

I don't think it matters too much, but for reference, here is the designer code that sets up detailTable:

this.detailTable.ColumnCount = 2;
this.detailTable.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle());
this.detailTable.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle());
this.detailTable.Dock = System.Windows.Forms.DockStyle.Fill;
this.detailTable.Location = new System.Drawing.Point(0, 0);
this.detailTable.Name = "detailTable";
this.detailTable.RowCount = 1;
this.detailTable.RowStyles.Add(new System.Windows.Forms.RowStyle());
this.detailTable.Size = new System.Drawing.Size(266, 436);
this.detailTable.TabIndex = 0;

This all works just fine. You should be aware that there appear to be some problems with disposing controls from a TableLayoutPanel dynamically using the Controls property (at least in some versions of the framework). If you need to remove controls, I suggest disposing the entire TableLayoutPanel and creating a new one.

Create a table layout panel with two columns in your form and name it tlpFields.

Then, simply add new control to table layout panel (in this case I added 5 labels in column-1 and 5 textboxes in column-2).

tlpFields.RowStyles.Clear();  //first you must clear rowStyles

for (int ii = 0; ii < 5; ii++)
{
    Label l1= new Label();
    TextBox t1 = new TextBox();

    l1.Text = "field : ";

    tlpFields.Controls.Add(l1, 0, ii);  // add label in column0
    tlpFields.Controls.Add(t1, 1, ii);  // add textbox in column1

    tlpFields.RowStyles.Add(new RowStyle(SizeType.Absolute,30)); // 30 is the rows space
}

Finally, run the code.

I just looked into my code. In one application, I just add the controls, but without specifying the index, and when done, I just loop through the row styles and set the size type to AutoSize. So just adding them without specifying the indices seems to add the rows as intended (provided the GrowStyle is set to AddRows).

In another application, I clear the controls and set the RowCount property to the needed value. This does not add the RowStyles. Then I add my controls, this time specifying the indices, and add a new RowStyle (RowStyles.Add(new RowStyle(...)) and this also works.

So, pick one of these methods, they both work. I remember the headaches the table layout panel caused me.

Winforms TableLayoutPanel adding rows programmatically

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