从文件中读取并根据c#字符分割信息

我正在从文本文件中读取信息，我想通过文本文件一行一行，并在每一行我想根据一个字符(例如)从其他分裂每个句子。'，')，我想把数据保存在数组中，但当我打印它时，我得到的只是最后的结果。

     private void button1_Click_1(object sender, EventArgs e)
    {
        string StringArray = null;
        //to get the browsed file and get sure it is not curropted
        try 
        {
            DialogResult result = openFileDialog1.ShowDialog();
            if (result == DialogResult.OK)
            {
                using (StreamReader sr = new StreamReader(openFileDialog1.FileName))
                {
                    string data;
                    while ((data = sr.ReadLine()) != null)
                    {
                    StringArray = data.Split(',');
                    }
                }
                   for (int i = 0; i < StringArray.Length; i++)
                    {
                        textBox1.Text = StringArray[i];
                    }
                FilePath.Text = openFileDialog1.FileName;
                textBox1.Text = (string)File.ReadAllText(FilePath.Text);
            }
        }
        catch(IOException ex) 
        {
            MessageBox.Show("there is an error" + ex+ "in the file please try again");
        }

    }