SqlDataAdapter.RowUpdating 事件

定义

Update(DataSet)在对数据源执行命令之前发生。 尝试更新时会触发事件。

public:
 event Microsoft::Data::SqlClient::SqlRowUpdatingEventHandler ^ RowUpdating;
public event Microsoft.Data.SqlClient.SqlRowUpdatingEventHandler RowUpdating;
member this.RowUpdating : Microsoft.Data.SqlClient.SqlRowUpdatingEventHandler 
Public Custom Event RowUpdating As SqlRowUpdatingEventHandler 

事件类型

示例

以下示例演示如何同时使用 RowUpdatingRowUpdated 事件。

using System;
using System.Data;
using System.Data.Common;
using System.Windows.Forms;
using System.Xml;
using Microsoft.Data.SqlClient;

public class Form1 : Form
{
    private DataSet DataSet1;
    private DataGrid dataGrid1;

    // handler for RowUpdating event
    private static void OnRowUpdating(object sender, SqlRowUpdatingEventArgs e)
    {
        PrintEventArgs(e);
    }

    // handler for RowUpdated event
    private static void OnRowUpdated(object sender, SqlRowUpdatedEventArgs e)
    {
        PrintEventArgs(e);
    }

    public static int Main()
    {
        const string connectionString = "Integrated Security=SSPI;database=Northwind;server=MSSQL1";
        const string queryString = "SELECT * FROMProducts";

        // create DataAdapter
        SqlDataAdapter adapter = new SqlDataAdapter(queryString, connectionString);
        SqlCommandBuilder builder = new SqlCommandBuilder(adapter);

        // Create and fill DataSet (select only first 5 rows)
        DataSet dataSet = new DataSet();
        adapter.Fill(dataSet, 0, 5, "Table");

        // Modify DataSet
        DataTable table = dataSet.Tables["Table"];
        table.Rows[0][1] = "new product";

        // add handlers
        adapter.RowUpdating += new SqlRowUpdatingEventHandler(OnRowUpdating);
        adapter.RowUpdated += new SqlRowUpdatedEventHandler(OnRowUpdated);

        // update, this operation fires two events
        // (RowUpdating/RowUpdated) per changed row
        adapter.Update(dataSet, "Table");

        // remove handlers
        adapter.RowUpdating -= new SqlRowUpdatingEventHandler(OnRowUpdating);
        adapter.RowUpdated -= new SqlRowUpdatedEventHandler(OnRowUpdated);
        return 0;
    }

    private static void PrintEventArgs(SqlRowUpdatingEventArgs args)
    {
        Console.WriteLine("OnRowUpdating");
        Console.WriteLine("  event args: (" +
            " command=" + args.Command +
            " commandType=" + args.StatementType +
            " status=" + args.Status + ")");
    }

    private static void PrintEventArgs(SqlRowUpdatedEventArgs args)
    {
        Console.WriteLine("OnRowUpdated");
        Console.WriteLine("  event args: (" +
            " command=" + args.Command +
            " commandType=" + args.StatementType +
            " recordsAffected=" + args.RecordsAffected +
            " status=" + args.Status + ")");
    }
}

RowUpdating 事件返回以下输出:

event args: (command=Microsoft.Data.SqlClient.SqlCommand commandType=2 status=0)

RowUpdated 事件返回以下输出:

event args: (command=Microsoft.Data.SqlClient.SqlCommand commandType=2 recordsAffected=1 row=System.Data.DataRow[37] status=0)

注解

使用 Update(DataSet)时,每个数据行更新有两个事件。 执行顺序如下所示:

  1. DataRow 中的值将移动到参数值。
  2. 引发 RowUpdating 事件。
  3. 该命令执行。
  4. 如果命令设置为 FirstReturnedRecord,则第一个返回的结果将放置在 DataRow中。
  5. 如果有输出参数,则它们放置在 DataRow中。
  6. 引发 RowUpdated 事件。
  7. 调用 AcceptChanges()

适用于