编辑后C＃保存DataGridView（覆盖导入的Excel文件）

Question

I have a small form which has 3 Buttons ( Browse & updateExcel & saveExcel ), a ComboBox ( comboBox1 ) and a DataGridView ( dataGridView1 )

The first button lets you select an Excel file and then loads in the file to the DataGridView :

private void Browse_Click(object sender, EventArgs e)
    {

        OpenFileDialog op = new OpenFileDialog();
        op.InitialDirectory = @"C:\";
        op.Title = "Browse Excel Files";
        op.CheckFileExists = true;
        op.CheckPathExists = true;
        op.DefaultExt = "xls";
        op.Filter = "Excel Files|*.xls;*.xlsx;*.xlsm;*.csv";
        op.FilterIndex = 2;
        op.RestoreDirectory = true;
        op.ReadOnlyChecked = true;
        op.ShowReadOnly = true;

        if (op.ShowDialog() == System.Windows.Forms.DialogResult.OK)
        {
            if (File.Exists(op.FileName))
            {
                string[] Arr = null;
                Arr = op.FileName.Split('.');
                if (Arr.Length > 0)
                {
                    if (Arr[Arr.Length - 1] == "xls")
                        sConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" +
                        op.FileName + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1'";
                }
                else if (Arr[Arr.Length - 1] == "xlsx")
                {
                    sConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + op.FileName + ";Extended Properties='Excel 12.0 Xml;HDR=YES';";
                }
            }
            FillData();
        }
    }

This also uses the following code:

    public string sConnectionString;
    private void FillData()
    {
        if (sConnectionString.Length > 0)
        {
            OleDbConnection cn = new OleDbConnection(sConnectionString);
            {
                cn.Open();
                DataTable dt = new DataTable();
                OleDbDataAdapter Adpt = new OleDbDataAdapter("select * from [sheet1$]", cn);
                Adpt.Fill(dt);
                dataGridView1.DataSource = dt;
            }
            try { }
            catch (Exception ex)
            {
            }
        }
    }

Then after you select a value from the ComboBox you can then update the DataGridView with this value as required by clicking the updateExcel button which uses this code:

    private void updateExcel_Click(object sender, EventArgs e)
    {
        for (int i = 0; i < dataGridView1.RowCount - 1; i++)
        {
            dataGridView1[2, i].Value = ConsigneeCombo.Text;
        }
    }

What I want to do is then click the Save button ( saveExcel ) and it save the loaded file with an Are you sure you want to save? Yes or No standard Windows dialogue box.

I have tried using the SaveFileDialogue ( saveFileDialog1 ) to do this:

    private void saveExcel_Click(object sender, EventArgs e)
    {
        SaveFileDialog saveFileDialog1 = new SaveFileDialog();
        saveFileDialog1.InitialDirectory = @"C:\";
        saveFileDialog1.Title = "Save Excel File";
        saveFileDialog1.DefaultExt = "xls";
        saveFileDialog1.Filter = "Excel Files|*.xls;*.xlsx;*.xlsm;*.csv";
        saveFileDialog1.FilterIndex = 2;
        saveFileDialog1.ShowDialog();

        if (saveFileDialog1.FileName != "")
        {
            System.IO.FileStream fs = (System.IO.FileStream)saveFileDialog1.OpenFile();
            fs.Close();
        }
    }

But this doesn't work as tries to save the file as a new file (with a new tab name etc) and it actually doesn't recognise the file type.

Answer 1

I solved this by using the following code:

    private void saveExcel_Click(object sender, EventArgs e)
    {

        SaveFileDialog sfd = new SaveFileDialog();
        sfd.InitialDirectory = @"C:\";
        sfd.Title = "Save Excel Files";
        sfd.CheckPathExists = true;
        sfd.DefaultExt = "xls";
        sfd.Filter = "Excel Files|*.xls;*.xlsx;*.xlsm;*.csv";
        sfd.FileName = "*.csv";
        if (sfd.ShowDialog() == DialogResult.OK)
        {
            ToCsV(dataGridView1, sfd.FileName);
        }
    }