Datatable, bindingsource and datagridview

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Hi,

I made a DataSet, and bounded (DataSource/BindningSource) it to a DataGridView.

From here the user can type in (double) values which I can later use for my calculations.

I've added a button for saving and loading the tables. When i Load/Opens a table the values are displaying in the Form-DataGridView, but I don't manage to connect/set it to the DataSet.

Below is the main load/open code. Here without the Dataset; data_vault.Revenue.

C#

private void Open_Click(object sender, EventArgs e)
        {
            //open a table
            OpenFileDialog open_data = new OpenFileDialog();
            open_data.Title = "Open file";
            open_data.Filter = "XML Files (*.xml)|*.xml";

            if (open_data.ShowDialog() == DialogResult.OK)
            {
                //Leser filen
                StreamReader read_table = new StreamReader(File.OpenRead(open_data.FileName));

                //Nye rader i tabellen

                DataTable dtable = new DataTable();
                dtable.Columns.Add(new DataColumn("L2_n", typeof(double)));
                dtable.Columns.Add(new DataColumn("L1_n", typeof(double)));



                //Splitter tekstfilen
                List<string> s_list = new List<string>();

                string str = read_table.ReadLine();
                char[] spearator = { '.', ' ' };


                String[] strlist = str.Split(spearator);
                foreach (String s in strlist)
                {
                    s_list.Add(s);
                }


                int count = s_list.Count;
                int i = 0;

                //Setter inn verdier i tabell
                for (int j = 0; j < (count - 1) / 2; j++)
                {
                    DataRow RowValues = dtable.NewRow();
                    double d = Double.Parse(s_list[i]);


                    RowValues[0] = Double.Parse(s_list[i]);
                    i++;
                    RowValues[1] = Double.Parse(s_list[i]);
                    i++;

                    dtable.Rows.Add(RowValues);                    
                }

                dataGridView1.DataSource = dtable;
            }

        }

Later I'm collecting the values;

C#

 private void button1_Click(object sender, EventArgs e)
        {
            //OK button

            //Liste lengder
            int i = 0;
            foreach (var obj in data_vault.Revenue)
            {
                double l2_tall = (Double)dataGridView1["l2nDataGridViewTextBoxColumn", i].Value;


                double l1_tall = (Double)dataGridView1["l1nDataGridViewTextBoxColumn", i].Value;


                i++;
            }
Line straight_line = Line.CreateBound(l2_tall , l1_tall);
}

What I have tried:

I've tried to Add, clone, New Object and loop through to set det values. Also
OleDbDataAdapter -> adapter.Update(dtable); and SQL

..but probably with some errors.

Posted 7-Feb-20 2:46am

camibo

Updated 9-Feb-20 23:20pm

v3

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Comments

Richard MacCutchan 7-Feb-20 9:13am

Why do you create a list from the data, instead of adding it direct to the DataTable? And why are the column names you use to refer to the DataGridView different to the column names in the DataTable?

camibo 7-Feb-20 9:25am

Hi and thank you for your quick replay.

Maybe there is no good reason for that. :S
1. The list of strings are made to split the textfile previously saving the table. Adding it back to a table I can set to the DataSet (was the idea anyway).
2. The names of the columns are "Previewing" the same.

Richard MacCutchan 7-Feb-20 9:54am

1. All that is needed is to split the string and then convert each number to a Double and store in a new DataRow. The List is not needed. By the way it is better to use Double.TryParse rather than Convert.ToDouble, as that will catch any bad string values.

2. According to your code above the names are not the same.

camibo 10-Feb-20 2:54am

Good morning,
From what I can understand, that is what i am doing. I now have the DataRow with the correct stored values. all values are displaying as they should.

However I'm not sure I understand how to update the datatble so that I can use the values for further calculations later. I think I get a bit confused for what is the datatable holding the values in the datagridview. What is the name here for the datatable I should store the DataRow values in?

For the l2_test and l1_test list. These are only used for a set/get function I made and is not "interferring" with the code.

Richard MacCutchan 10-Feb-20 3:13am

If you need to change any values then you must change them in the DataTable, as that is the source for the DataGridView. If you change them in the DataGridView then the source and display will by out of sync.

camibo 10-Feb-20 3:16am

1. So; dataGridView1.DataSource = dtable;
updates the view?
2. Can you provide an script example for how to update the DataTable?
3. I don't see how the DataTable dtable are linked to the datagridview/datasource.?

Richard MacCutchan 10-Feb-20 3:59am

1. No it sets the binding between the source data and the destination display.
2. Just update any rows and columns as you need to.
3.

dataGridView1.DataSource = dtable; // this is how it is linked

camibo 10-Feb-20 4:14am

If that is so, then I don't understand why the code is not working as it is?
I've made a table that is correctly displaying the values in the view, but the values will not be stored. See attached video.

camibo 10-Feb-20 4:18am

Can you send me an email adress, than I can send you the video displaying the issue? :)

Richard MacCutchan 10-Feb-20 4:33am

What do you mean by "but the values will not be stored."?

And no, you cannot have my email address. Questions, answers and comments all stay here in the forums.

camibo 10-Feb-20 4:38am

1. If I type in values in the form, the code will produce as I wish.
2. If I load the same (saved) table. The table will display in the form correctly. But the code will not generate anything.

I made I video showing the issue, but I don't see how i can upload it in the forum.

Richard MacCutchan 10-Feb-20 5:12am

Sorry that does not make anything clear. I suggest you open a new question and clearly show all the code that you are referring to, and explain in detail what results you are seeing, or not seeing.

You cannot upload videos to these forums, to protect against inappropriate materials.

camibo 10-Feb-20 5:21am

Now I've updated the code.
If i type in values in the form-dataviewgrid, the code is working.
If i load values into the datagridview, the values display in the form, but code is not creating the line.

Richard MacCutchan 10-Feb-20 5:28am

foreach (var obj in data_vault.Revenue)
{
    double l2_tall = (Double)dataGridView1["l2nDataGridViewTextBoxColumn", i].Value;

    double l1_tall = (Double)dataGridView1["l1nDataGridViewTextBoxColumn", i].Value;

    i++;
}

So, at the end of that loop you have no data saved anywhere, and the two variables have been disposed as they only exist inside the loop.

camibo 10-Feb-20 5:30am

When I load the table, the code does'nt run inside the foreach loop at all.

There are no data "var obj in data_vault.Revenue"

Richard MacCutchan 10-Feb-20 5:47am

What is data_vault and where is it created?

camibo 10-Feb-20 6:21am

Data_vault.xsd is the DataSet.

private Data_vault data_vault; (Form.data_vault)

Richard MacCutchan 10-Feb-20 6:49am

That is just another variable you are introducing with no information about what it actually is and where it is created. Your code is referring to an object that you have not shown anywhere so we cannot guess its purpose, or its connection to the rest of this question.

camibo 10-Feb-20 7:05am

As i have understood it;
- It's created in the Form.Designer.
- The variable comes from the DataSet - Data_vault.xsd

Here are the proparties / sets from Form.Designer

// dataGridView1
//
this.dataGridView1.AutoGenerateColumns = false;
this.dataGridView1.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
this.dataGridView1.Columns.AddRange(new System.Windows.Forms.DataGridViewColumn[] {
this.l2nDataGridViewTextBoxColumn,
this.l1nDataGridViewTextBoxColumn});
this.dataGridView1.DataSource = this.revenueBindingSource;
this.dataGridView1.Location = new System.Drawing.Point(38, 313);
this.dataGridView1.Name = "dataGridView1";
this.dataGridView1.Size = new System.Drawing.Size(183, 214);
this.dataGridView1.TabIndex = 0;
this.toolTip_tabell.SetToolTip(this.dataGridView1, "Liste med lengder [m] på hver siden av hvelvet. Her for hver meter i høyden");
this.dataGridView1.CellContentClick += new System.Windows.Forms.DataGridViewCellEventHandler(this.dataGridView1_CellContentClick);
//
// l2nDataGridViewTextBoxColumn
//
this.l2nDataGridViewTextBoxColumn.AutoSizeMode = System.Windows.Forms.DataGridViewAutoSizeColumnMode.ColumnHeader;
this.l2nDataGridViewTextBoxColumn.DataPropertyName = "L2_n";
this.l2nDataGridViewTextBoxColumn.HeaderText = "L2_n";
this.l2nDataGridViewTextBoxColumn.Name = "l2n_DataGridViewTextBoxColumn";
this.l2nDataGridViewTextBoxColumn.Width = 56;
//
// l1nDataGridViewTextBoxColumn
//
this.l1nDataGridViewTextBoxColumn.AutoSizeMode = System.Windows.Forms.DataGridViewAutoSizeColumnMode.ColumnHeader;
this.l1nDataGridViewTextBoxColumn.DataPropertyName = "L1_n";
this.l1nDataGridViewTextBoxColumn.HeaderText = "L1_n";
this.l1nDataGridViewTextBoxColumn.Name = "l1n_DataGridViewTextBoxColumn";
this.l1nDataGridViewTextBoxColumn.Width = 56;
//
// revenueBindingSource
//
this.revenueBindingSource.DataMember = "Revenue";
this.revenueBindingSource.DataSource = this.data_vault;
//
// data_vault
//
this.data_vault.DataSetName = "Data_vault";
this.data_vault.SchemaSerializationMode = System.Data.SchemaSerializationMode.IncludeSchema;

Richard MacCutchan 10-Feb-20 7:30am

So you have a binding source between data_vault and the DataGridView. Then on loading your form you read some data from a file into a DataTable and bind that to your DataGridView. I think you need to look at the design of your application and decide which data source actually contains the information that you wish to process.

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