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How to: Share Bound Data Across Forms Using the BindingSource Component

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You can easily share data across forms using the BindingSource component. For example, you may want to display one read-only form that summarizes the data-source data and another editable form that contains detailed information about the currently selected item in the data source. This example demonstrates this scenario.

Example

The following code example demonstrates how to share a BindingSource and its bound data across forms. In this example, the shared BindingSource is passed to the constructor of the child form. The child form allows the user to edit the data for the currently selected item in the main form.

Note

The BindingComplete event for the BindingSource component is handled in the example to ensure that the two forms remain synchronized. For more information about why this is done, see How to: Ensure Multiple Controls Bound to the Same Data Source Remain Synchronized.

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Data;

namespace BindingSourceMultipleForms
{
    public class MainForm : Form
    {
        public MainForm()
        {
            this.Load += new EventHandler(MainForm_Load);
        }

        private BindingSource bindingSource1;
        private Button button1;

        private void MainForm_Load(object sender, EventArgs e)
        {
            InitializeData();
        }

        private void InitializeData()
        {
            bindingSource1 = new System.Windows.Forms.BindingSource();

            // Handle the BindingComplete event to ensure the two forms
            // remain synchronized.
            bindingSource1.BindingComplete +=
                new BindingCompleteEventHandler(bindingSource1_BindingComplete);
            ClientSize = new System.Drawing.Size(292, 266);
            DataSet dataset1 = new DataSet();

            // Some xml data to populate the DataSet with.
            string musicXml =
                "<?xml version='1.0' encoding='UTF-8'?>" +
                "<music>" +
                 "<recording><artist>Dave Matthews</artist>" +
                 "<cd>Under the Table and Dreaming</cd>" +
                 "<releaseDate>1994</releaseDate><rating>3.5</rating></recording>" +
                 "<recording><artist>Coldplay</artist><cd>X&amp;Y</cd>" +
                 "<releaseDate>2005</releaseDate><rating>4</rating></recording>" +
                 "<recording><artist>Dave Matthews</artist>" +
                 "<cd>Live at Red Rocks</cd>" +
                 "<releaseDate>1997</releaseDate><rating>4</rating></recording>" +
                 "<recording><artist>U2</artist>" +
                 "<cd>Joshua Tree</cd><releaseDate>1987</releaseDate>" +
                 "<rating>5</rating></recording>" +
                 "<recording><artist>U2</artist>" +
                 "<cd>How to Dismantle an Atomic Bomb</cd>" +
                 "<releaseDate>2004</releaseDate><rating>4.5</rating></recording>" +
                 "<recording><artist>Natalie Merchant</artist>" +
                 "<cd>Tigerlily</cd><releaseDate>1995</releaseDate>" +
                 "<rating>3.5</rating></recording>" +
                 "</music>";

            // Read the xml.
            System.IO.StringReader reader = new System.IO.StringReader(musicXml);
            dataset1.ReadXml(reader);

            // Get a DataView of the table contained in the dataset.
            DataTableCollection tables = dataset1.Tables;
            DataView view1 = new DataView(tables[0]);

            // Create a DataGridView control and add it to the form.
            DataGridView datagridview1 = new DataGridView();
            datagridview1.ReadOnly = true;
            datagridview1.AutoGenerateColumns = true;
            datagridview1.Width = 300;
            this.Controls.Add(datagridview1);
            bindingSource1.DataSource = view1;
            datagridview1.DataSource = bindingSource1;
            datagridview1.Columns.Remove("artist");
            datagridview1.Columns.Remove("releaseDate");

            // Create and add a button to the form.
            button1 = new Button();
            button1.AutoSize = true;
            button1.Text = "Show/Edit Details";
            this.Controls.Add(button1);
            button1.Location = new Point(50, 200);
            button1.Click += new EventHandler(button1_Click);
        }

        // Handle the BindingComplete event to ensure the two forms
        // remain synchronized.
        private void bindingSource1_BindingComplete(object sender, BindingCompleteEventArgs e)
        {
            if (e.BindingCompleteContext == BindingCompleteContext.DataSourceUpdate
                && e.Exception == null)
                e.Binding.BindingManagerBase.EndCurrentEdit();
        }

        // The detailed form will be shown when the button is clicked.
        private void button1_Click(object sender, EventArgs e)
        {
            DetailForm detailForm = new DetailForm(bindingSource1);
            detailForm.Show();
        }

        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.Run(new MainForm());
        }
    }

    // The detail form class.
    public class DetailForm : Form
    {
        private BindingSource formDataSource;

        // The constructor takes a BindingSource object.
        public DetailForm(BindingSource dataSource)
        {
            formDataSource = dataSource;
            this.ClientSize = new Size(240, 200);
            TextBox textBox1 = new TextBox();
            this.Text = "Selection Details";
            textBox1.Width = 220;
            TextBox textBox2 = new TextBox();
            TextBox textBox3 = new TextBox();
            TextBox textBox4 = new TextBox();
            textBox4.Width = 30;
            textBox3.Width = 50;

            // Associate each text box with a column from the data source.
            textBox1.DataBindings.Add("Text", formDataSource, "cd", true, DataSourceUpdateMode.OnPropertyChanged);

            textBox2.DataBindings.Add("Text", formDataSource, "artist", true);
            textBox3.DataBindings.Add("Text", formDataSource, "releaseDate", true);
            textBox4.DataBindings.Add("Text", formDataSource, "rating", true);
            textBox1.Location = new Point(10, 10);
            textBox2.Location = new Point(10, 40);
            textBox3.Location = new Point(10, 80);
            textBox4.Location = new Point(10, 120);
            this.Controls.AddRange(new Control[] { textBox1, textBox2, textBox3, textBox4 });
        }
    }
}

Compiling the Code

This example requires:

  • References to the System, System.Windows.Forms, System.Drawing, System.Data, and System.Xml assemblies.

See also