Windows Forms: How to read text file (*.txt) in C#

Step 1: Click New Project, then select Visual C# on the left, then Windows and then select Windows Forms Application. Name your project "ReadTxtFile" and then click OK

Step 2: Design your form as below

Step 3: Add code to button click event handler as below

private async void btnOpen_Click(object sender, EventArgs e)
{
    try
    {
        //Open file dialog, allows you to select a txt file
        using (OpenFileDialog ofd = new OpenFileDialog() { Filter = "Text Documents|*.txt", Multiselect = false, ValidateNames = true })
        {
            if (ofd.ShowDialog() == DialogResult.OK)
            {
                using (StreamReader sr = new StreamReader(ofd.FileName))
                {
                    txtValue.Text = await sr.ReadToEndAsync();
                }
            }
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message, "Message", MessageBoxButtons.OK, MessageBoxIcon.Error);
    }
}

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