DataGrid的稍进一步的应用（未完成）

下面这段代码是一个完整的文件，原代码来自WROX.COM，演示了DataGrid的稍进一步的应用。

using System;
using System.Windows.Forms;
using System.Data;
using System.Data.OleDb;

/**////    <summary>
///    This class provides    an example of creating and using a data    grid.
///    </summary>
public class DataSourceDataView : System.Windows.Forms.Form
{
    private System.Windows.Forms.Button retrieveButton;
    private System.Windows.Forms.DataGrid dataGrid;
    private System.Windows.Forms.DataGrid dataGrid2;
    private System.Windows.Forms.ComboBox comboBox1;

    /**////    <summary>
    ///    Construct the window.
    ///    </summary>
    ///    <remarks>
    ///    This method    constructs the window by creating both the data    grid and the button.
    ///    </remarks>
    public DataSourceDataView()
    {
        /**//*        this.AutoScaleBaseSize = new System.Drawing.Size (5, 13);
                this.ClientSize    = new System.Drawing.Size (464,    253);
                this.Text =    "04_DataSourceDataView" ;
                this.dataGrid =    new    System.Windows.Forms.DataGrid ();
                dataGrid.BeginInit ();
                dataGrid.Location =    new    System.Drawing.Point (8, 8);
                dataGrid.Size =    new    System.Drawing.Size    (448, 208);
                dataGrid.TabIndex =    0;
                dataGrid.Anchor    = AnchorStyles.Bottom | AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right ;
                this.Controls.Add (this.dataGrid);
                dataGrid.EndInit ();
                this.retrieveButton    = new System.Windows.Forms.Button ();
                retrieveButton.Location    = new System.Drawing.Point (384, 224);
                retrieveButton.Size    = new System.Drawing.Size (75, 23);
                retrieveButton.TabIndex    = 1;
                retrieveButton.Anchor =    AnchorStyles.Bottom | AnchorStyles.Right ;
                retrieveButton.Text    = "Retrieve";
                retrieveButton.Click +=    new    System.EventHandler    (this.retrieveButton_Click);
                this.Controls.Add (this.retrieveButton); */

        this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
        this.ClientSize = new System.Drawing.Size(464, 493);
        this.Text = "04_DataSourceDataView";
        this.dataGrid = new System.Windows.Forms.DataGrid();
        dataGrid.BeginInit();
        dataGrid.CaptionText = "From Database";
        dataGrid.Font = new System.Drawing.Font("Tahoma", 8);
        dataGrid.Location = new System.Drawing.Point(8, 8);
        dataGrid.Size = new System.Drawing.Size(448, 208);
        dataGrid.TabIndex = 0;
        dataGrid.Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right;
        this.Controls.Add(this.dataGrid);
        dataGrid.EndInit();

        this.retrieveButton = new System.Windows.Forms.Button();
        retrieveButton.Location = new System.Drawing.Point(8, 224);
        retrieveButton.Size = new System.Drawing.Size(75, 23);
        retrieveButton.TabIndex = 1;
        retrieveButton.Anchor = AnchorStyles.Top | AnchorStyles.Left;
        retrieveButton.Text = "Retrieve";
        retrieveButton.Click += new System.EventHandler(this.retrieveButton_Click);
        this.Controls.Add(this.retrieveButton);

        this.comboBox1 = new System.Windows.Forms.ComboBox();
        comboBox1.Location = new System.Drawing.Point(96, 224);
        comboBox1.Size = new System.Drawing.Size(360, 21);
        comboBox1.DropDownStyle = ComboBoxStyle.DropDownList;
        comboBox1.TabIndex = 2;
        comboBox1.Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right;
        comboBox1.SelectedIndexChanged += new System.EventHandler(this.comboBox1_SelectedIndexChanged);
        comboBox1.Items.AddRange(new object[8] { "Added", "CurrentRows", "Deleted", "ModifiedCurrent", "ModifiedOriginal", "None", "OriginalRows", "Unchanged" });
        this.Controls.Add(this.comboBox1);

        this.dataGrid2 = new System.Windows.Forms.DataGrid();
        dataGrid2.BeginInit();
        dataGrid2.Location = new System.Drawing.Point(8, 256);
        dataGrid2.Size = new System.Drawing.Size(448, 232);
        dataGrid2.DataMember = "";
        dataGrid2.CaptionText = "Filtered";
        dataGrid2.Font = new System.Drawing.Font("Tahoma", 8);
        dataGrid2.TabIndex = 3;
        dataGrid2.Anchor = AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Bottom | AnchorStyles.Right;
        this.Controls.Add(this.dataGrid2);
        dataGrid2.EndInit();

    }

    protected void comboBox1_SelectedIndexChanged(object sender, System.EventArgs e)
    {
        DataViewRowState state;

        switch (comboBox1.Text)
        {
            case "Added":
                state = DataViewRowState.Added;
                break;
            case "CurrentRows":
                state = DataViewRowState.CurrentRows;
                break;
            case "Deleted":
                state = DataViewRowState.Deleted;
                break;
            case "ModifiedCurrent":
                state = DataViewRowState.ModifiedCurrent;
                break;
            case "ModifiedOriginal":
                state = DataViewRowState.ModifiedOriginal;
                break;
            case "None":
                state = DataViewRowState.None;
                break;
            case "OriginalRows":
                state = DataViewRowState.OriginalRows;
                break;
            case "Unchanged":
                state = DataViewRowState.Unchanged;
                break;
            default:
                state = DataViewRowState.OriginalRows;
                break;
        }

        try
        {
            ((DataView)dataGrid2.DataSource).RowStateFilter = state;
        }
        catch (Exception ex)
        {
            System.Windows.Forms.MessageBox.Show(ex.ToString());

        }
    }

    /**////    <summary>
    ///    Retrieve the data
    ///    </summary>
    ///    <param name="sender"> </param>
    ///    <param name="e"> </param>
    protected void retrieveButton_Click(object sender, System.EventArgs e)
    {
        retrieveButton.Enabled = false;

        string select = "SELECT * FROM MainInfo";

        OleDbConnection con = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Documents and Settings\Manio\My Documents\PrintManager\program\PrintManageV1\DataBase\PrintDB.mdb");

        OleDbDataAdapter da = new OleDbDataAdapter(select, con);

        DataSet ds = new DataSet();

        da.Fill(ds, "MainInfo");

        dataGrid.SetDataBinding(ds, "MainInfo");

        DataView dv = new DataView(ds.Tables["MainInfo"]);

        dataGrid2.SetDataBinding(dv, null);

        comboBox1.Text = "OriginalRows";
    }

    /**////    <summary>
    ///    Display    the    application    window
    ///    </summary>
    static void Main()
    {
        Application.Run(new DataSourceDataView());
    }
}

DataViewManager的用法：
DataViewManager创建时会同时创建一个DataSet中DataTable的DataView，根据过滤条件改变显示出来的行或者行的状态。即使不希望过滤数据，也可以把DataSet包装到DataViewManager中，以进行显示，因为这样在修改代码时可以使用更多的选项。

先来看一下DataViewManager的一个简单应用。下面的例子是本博客中另一篇文章《DataGrid实例（简单易懂，无复杂功能，适合初学者）》的一个实例改过来的，我们改用DataViewManager来显示数据，一看就明白。代码如下，和《DataGrid一文》不同之处已注明。

using System;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;
using System.Data.OleDb;
//Professional C# 2nd的DATAGRID实例
/**////    <summary>
///    This class provides    an example of creating and using a data    grid.
///    </summary>
public class DisplayTabularData : System.Windows.Forms.Form
{
    private System.Windows.Forms.Button retrieveButton;
    private System.Windows.Forms.DataGrid dataGrid;

    /**////    <summary>
    ///    Construct the window.
    ///    </summary>
    ///    <remarks>
    ///    This method    constructs the window by creating both the data    grid and the button.
    ///    </remarks>
    public DisplayTabularData()
    {
        this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
        this.ClientSize = new System.Drawing.Size(464, 253);
        this.Text = "01_DisplayTabularData";
        this.dataGrid = new System.Windows.Forms.DataGrid();
        dataGrid.BeginInit();
        dataGrid.Location = new System.Drawing.Point(8, 8);
        dataGrid.Size = new System.Drawing.Size(448, 208);
        dataGrid.TabIndex = 0;
        dataGrid.Anchor = AnchorStyles.Bottom | AnchorStyles.Top | AnchorStyles.Left | AnchorStyles.Right;
        this.Controls.Add(this.dataGrid);
        dataGrid.EndInit();
        this.retrieveButton = new System.Windows.Forms.Button();
        retrieveButton.Location = new System.Drawing.Point(384, 224);
        retrieveButton.Size = new System.Drawing.Size(75, 23);
        retrieveButton.TabIndex = 1;
        retrieveButton.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;
        retrieveButton.Text = "Retrieve";
        retrieveButton.Click += new System.EventHandler(this.retrieveButton_Click);
        this.Controls.Add(this.retrieveButton);
    }

    /**////    <summary>
    ///    Retrieve the data
    ///    </summary>
    ///    <param name="sender"> </param>
    ///    <param name="e"> </param>
    protected void retrieveButton_Click(object sender, System.EventArgs e)
    {
        retrieveButton.Enabled = false;

        string source = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Documents and Settings\Manio\My Documents\PrintManager\program\PrintManageV1\DataBase\PrintDB.mdb";
        string select = "SELECT * FROM MainInfo";

        /**/////////////////////////////////
        //填充DataSet的步骤
        //１、使用数据库连接字符串创建数据库连接对象
        //    ２、用SQL查询语句和数据库连接对象创建数据库适配器dataAdapter
        //        ３、使用DataAdapter的Fill 方法填充DataSet

        OleDbConnection OleCon = new OleDbConnection(source);

        OleDbDataAdapter da = new OleDbDataAdapter(select,OleCon);

        DataSet ds = new DataSet();

        da.Fill(ds, "MainInfo");
        /**/////////////////////////////////////////////////////////////////////////////////////////
        ////////////////////////////////////////////////////////////////////////////////////////
        //不用之处
        /**/////////////////////////////////////////////////////////////////////////////////////////

        DataViewManager dvm = new DataViewManager(ds);

        dvm.DataViewSettings["MainInfo"].RowFilter = "D_ID=2";
        dataGrid.SetDataBinding(dvm, "MainInfo");    
        /**/////////////////////////////////////////////////////////////////////////////////////////
        ////////////////////////////////////////////////////////////////////////////////////////
    }

    /**////    <summary>
    ///    Display    the    application    window
    ///    </summary>
    static void Main()
    {
        Application.Run(new DisplayTabularData());
    }
}