Newbie C# - DataSet AddRow (Solved)

Jeremy Fourman

Hello. Fairly new to C# and the DataSet concept.
I have a DataSet MediaDataSet1 that has one table MediaList with 3 columns.
I also have a form that has 3 textboxes and 2 buttons. One button to add the data input from the text boxes. One to output the data in the DataSet to XML. However the output never contains the data. I am not sure what is wrong. Below is the code in it's current state. Any help would be appreciated.

private void button1_Click(object sender, EventArgs e)
        {
            MediaDataSet1 mDS = new MediaDataSet1();
            //DataTable mDT = mDS.Tables["MediaList"];
            DataRow mDR = mDS.Tables["MediaList"].NewRow();
            mDR["MediaName"] = MediaNameTB.Text;
            mDR["MediaType"] = MediaTypeTB.Text;
            mDR["MediaLength"] = MediaLengthTB.Text;
            mDS.Tables["MediaList"].Rows.Add(mDR);
            //mDT.Rows.Add(mDR);
            //mDS.AcceptChanges();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            MediaDataSet1 mDS = new MediaDataSet1();
            mDS.WriteXml("C:\\Documents and Settings\\user003\\My Documents\\testOut.xml");
        }

The XML output always only contains this.

Many Thanks.
Jeremy

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Jeremy Fourman18y ago
OK yes, that should have been obvious to me. So how would I load a dataset and not create a new dataset every time when the "Add" button is clicked. I see the Load function is available to the mDS object now, but I am not sure if thats what I want.

Edit: Right now I am loading XML and rewriting with new entries to load on next media addition, this seems to be a heavy sort of action, what would be a better way?

Thank you .

Jeremy
Bechir Bejaoui18y ago
private void button1_Click(object sender, EventArgs e)
        {
            MediaDataSet1 mDS = new MediaDataSet1();
            //DataTable mDT = mDS.Tables["MediaList"];
            DataRow mDR = mDS.Tables["MediaList"].NewRow();
            mDR["MediaName"] = MediaNameTB.Text;
            mDR["MediaType"] = MediaTypeTB.Text;
            mDR["MediaLength"] = MediaLengthTB.Text;
            mDS.Tables["MediaList"].Rows.Add(mDR);
            //mDT.Rows.Add(mDR);
            //mDS.AcceptChanges();
        }

        private void button2_Click(object sender, EventArgs e)
        {
           OK my freind the problem is here I mean the line bellow
         when you use
           MediaDataSet1 mDS = new MediaDataSet1();
           That means that you define a new blanc dataset and you load it
            mDS.WriteXml("C:\\Documents and Settings\\user003\\My Documents\\testOut.xml");
        }

The XML output always only contains this.

to avoid such trouble try this instead:
MediaDataSet1 mDS;
private void button1_Click(object sender, EventArgs e)
        {
            mDS = new MediaDataSet1();
            //DataTable mDT = mDS.Tables["MediaList"];
            DataRow mDR = mDS.Tables["MediaList"].NewRow();
            mDR["MediaName"] = MediaNameTB.Text;
            mDR["MediaType"] = MediaTypeTB.Text;
            mDR["MediaLength"] = MediaLengthTB.Text;
            mDS.Tables["MediaList"].Rows.Add(mDR);
            //mDT.Rows.Add(mDR);
            //mDS.AcceptChanges();
        }

        private void button2_Click(object sender, EventArgs e)
        {

            mDS.WriteXml("C:\\Documents and Settings\\user003\\My Documents\\testOut.xml");
        }