Question

I’ve created a number of buttons on a form based on database entries, and they work just fine. Here’s the code for creating them. As you can see I’ve given them a tag:

for (int i = 0; i <= count && i < 3; i++)
{
    btnAdd.Text = dataTable.Rows[i]["deviceDescription"].ToString();
    btnAdd.Location = new Point(x, y);
    btnAdd.Tag = i;

    this.Controls.Add(btnAdd);
}

I use these buttons for visualising a polling system. For example, I want the button to be green when everything is fine, and red when something is wrong.

So the problem I’m running into is referencing the buttons later so that I can change their properties. I’ve tried stuff like the following:

this.Invoke((MethodInvoker)delegate
{
    // txtOutput1.Text = (result[4] == 0x00 ? "HIGH" : "LOW"); // runs on UI thread
    Button foundButton = (Button)Controls.Find(buttonNumber.ToString(), true)[0];
    if (result[4] == 0x00)
    {
        foundButton.BackColor = Color.Green;
    }
    else
    {
        foundButton.BackColor = Color.Red;
    }
});

But to no avail… I’ve tried changing around the syntax of Controls.Find() but still have had no luck. Has anyone encountered this problem before or know what to do?

Answer 1

If you name your buttons when you create them then you can find them from the this.controls(…

like this

for (int i = 0; i <= count && i < 3; i++)
    {
        Button btnAdd = new Button();
        btnAdd.Name="btn"+i;

        btnAdd.Text = dataTable.Rows[i]["deviceDescription"].ToString();
        btnAdd.Location = new Point(x, y);
        btnAdd.Tag = i;

        this.Controls.Add(btnAdd);
    }

then you can find it like this

this.Controls["btn1"].Text="New Text";

or

 for (int i = 0; i <= count && i < 3; i++)
{
//**EDIT**  I added some exception catching here
    if (this.Controls.ContainsKey("btn"+buttonNumber))
        MessageBox.Show("btn"+buttonNumber + " Does not exist");
    else
        this.Controls["btn"+i].Text="I am Button "+i;
}