How do I read a text file and put the data in my DataGridView?

private void write(object sender, EventArgs e)
{
    FileStream outputFileStream = new FileStream("test.txt", FileMode.Create, FileAccess.Write);
    StreamWriter writer = new StreamWriter(outputFileStream);
    Random r = new Random();

    for (int i = 0; i < dataGridView1.RowCount; i++)
    {
        for (int j = 0; j < dataGridView1.ColumnCount; j++)
        {
            double d = 0;
            Double.TryParse(Convert.ToString(dataGridView1.Rows[i].Cells[j].Value), out d);

            writer.Write(d + "\t");
        }
        writer.Write("\n");
    }

    writer.Close();
    outputFileStream.Close();
}

So this is my write method. It is supposed to save anything that the user entered on the DataGridView. It saves into a text file. I even tried opening the text file with an Excel and it displays exactly values and cell positions that were put in. It works fine.

Now the part I'm missing is how do I read the file back onto a DataGridView?

private void read(object sender, EventArgs e)
{

    char TAB = '\t';
    char NEWLINE = '\n';

    FileStream inputFileStream = new FileStream("test.txt", FileMode.Open, FileAccess.Read);
    StreamReader reader = new StreamReader(inputFileStream);

    string line;
    string[] fields;

    for (int i = 0; i < dataGridView1.RowCount; i++)
    {
        for (int j = 0; j < dataGridView1.ColumnCount; j++)
        {
            line = reader.ReadLine();
            fields = line.Split(TAB, NEWLINE);
            dataGridView1.Rows[i].Cells[j].Value = fields;
        }
    }
    inputFileStream.Close();
    reader.Close();
}

This is what I've tried so far. However, it will not display the values properly like an Excel. Now I don't want to save my file into an Excel but how do I read a text file and display all the grid data on the screen?