Question

I wrote a simple class to generate arrays as I needed some hard-coded random arrays for my own debugging purposes, however despite calling the timely operations in a separate worker thread my UI still hangs! Here’s the code…

    private static Random randGenerator = new Random();

    private void generateButton_Click(object sender, EventArgs e)
    {
        string dataType = "System.";
        if (typeComboBox.Text != "Byte")
            dataType += signedCheckBox.Checked ? "" : "U";
        else if (typeComboBox.Text == "Byte")
            dataType += signedCheckBox.Checked ? "S" : "";
        dataType += typeComboBox.Text;

        generateButton.Enabled = false;

        new Thread(() =>
            {
                Process(Type.GetType(dataType), (int)sizeNumericUpDown.Value, hexCheckBox.Checked);
            }).Start();
    }

    private void Process(Type type, int size, bool hex)
    {
        StringBuilder sBuilder = new StringBuilder();
        sBuilder.Append(string.Format(@"{0}[] values = new {0}[{1}] {{", type.Name, size));

        for (int i = 0; i < size; i++)
        {
            int random = randGenerator.Next(0, GetIntegralMaxValue(type));
            sBuilder.Append((hex ? "0x" + random.ToString("x2") : random.ToString()) + (i < size - 1 ? ", " : " };"));
        }

        outputTextBox.BeginInvoke((MethodInvoker)delegate
        {
            outputTextBox.Text = sBuilder.ToString();
        });
    }

    private int GetIntegralMaxValue(Type type)
    {
        var field = type.GetField("MaxValue").GetValue(null);
        return Convert.ToInt32(field);
    }

I thought that maybe the issue lied with trying to access objects created on the main thread so instead I passed them to the method. I also tried declaring my randGenerator object within the class but still no luck. Could anybody identify the issue?

Answer 1

The TextBox is not designed to hold a large set of data – it becomes very slow when amount of data increases. I would say that populating of the StringBuilder takes about 5% of time while assigning this data to TextBox (which executes in UI thread) takes remaining 95% of time. You can easily check this. Just run this code in debug mode and click “Pause” button during hanging. It should break on “outputTextBox.Text = sBuilder.ToString();” line.