Question

i want open a text,where i already type many strings and in after all that rows
i want to create a new row and write the information in.all the informations
about the new line i want to write i take it from textboxes

//button open file
private void button4_Click(object sender, EventArgs e)
    {
        if(openFileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
        {

            label7.Text = openFileDialog1.FileName;
            textBox7.Text = File.ReadAllText(label7.Text);
        }
    }


    //button save file
    private void button5_Click(object sender, EventArgs e)
    {
        if (saveFileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
        {

            File.WriteAllText(saveFileDialog1.FileName, textBox7.Text);
        }

    }

      //this is the add button
    private void button1_Click(object sender, EventArgs e)
       {

        string inValue1, inValue2, inValue3, inValue4, inValue5, inValue6;
        inValue1 = textBox1.Text;
        inValue2 = textBox2.Text;
        inValue3 = textBox3.Text;
        inValue4 = textBox4.Text;
        inValue5 = textBox5.Text;
        inValue6 = textBox6.Text;


        string result = (inValue1 + "," + inValue2 + "," + inValue3 + ","
            +inValue4+ "," +inValue5 + "," +inValue6);
        //File.WriteAllText("C:\\text.txt", textBox1.Text);
        System.IO.File.WriteAllText(@"C:\Users\v\Desktop\text.txt", result);
    }

Answer 1

It’s not entirely clear what you mean, but I suspect you just want File.AppendAllText:

File.AppendAllText(filename, "new line of text");

Or possibly, if the file doesn’t end with a line break at the moment:

File.AppendAllText(filename, Environment.NewLine + "new line of text");