VS重新启动后，SQL更改消失

我正在学习C＃和SQL交互的基础知识，并且具有以下形式：

它向我显示了使用VS 2013 DB Builder构建的预填充DB的值，上方的按钮一切正常。

这是我的桌子：

问题：

• 当我单击“添加新项”时，文本框将被清除；
• 接下来，填充文本框，当我单击“保存”时，该记录显然会添加到数据库（或至少添加到数据集？），因为它会给我一条成功的消息，并且当我使用上方的按钮浏览数据库时会显示该记录；
• 如果我关闭并重新打开我的应用程序（不关闭VS），则插入的记录仍然存在。
• 但是，如果我关闭并重新打开VS并再次运行我的应用程序，我输入的记录就消失了。
• 另外，如果不关闭VS，则转到服务器资源管理器（VS左窗格），用鼠标右键单击我的表=>显示表数据，新记录就永远不会存在。

这是Form1.cs代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace SQLtest
{
/// <summary>
/// A class that constains our form
/// </summary>
public partial class Form1 : Form
{
    // variables
    DBconnection objConnect;
    string conString;
    DataSet ds;
    DataRow dr;
    int maxRows;
    int inc = 0;

    /// <summary>
    /// Constructor of the class
    /// </summary>
    public Form1()
    {
        InitializeComponent();
    }

    /// <summary>
    /// Form initialization method
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void Form1_Load(object sender, EventArgs e)
    {
        try
        {
            objConnect = new DBconnection();
            conString = Properties.Settings.Default.TestConnectionString;

            objConnect.connection_string = conString;
            objConnect.Sql = Properties.Settings.Default.SQL;

            ds = objConnect.GetConnection;

            maxRows = ds.Tables[0].Rows.Count;
            // MessageBox.Show("Max Rows: " + maxRows);

            NavigateRecords();
        }
        catch (Exception err)
        {
            MessageBox.Show(err.Message);
        }
    }

    // DB Navigation Methods

    /// <summary>
    /// Sets pointer (inc) to last row
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void btnNext_Click(object sender, EventArgs e)
    {
        // prevent indexOutOfBounds error
        if (inc != maxRows - 1)
        {
            inc++;
            NavigateRecords();
        }
        else
        {
            MessageBox.Show("Reached last employee. Showing the first record.");
            inc = 0;
            NavigateRecords();
        }

    }

    /// <summary>
    /// Sets pointer (inc) to previous row (if possible)
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void btnPrevious_Click(object sender, EventArgs e)
    {
        // prevent indexOutOfBounds error
        if (inc != 0)
        {
            inc--;
            NavigateRecords();
        }
        else
        {
            MessageBox.Show("Reached first employee. Showing the last record.");
            inc = maxRows - 1;
            NavigateRecords();
        }
    }

    /// <summary>
    /// Sets pointer (inc) to first row
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void btnFirst_Click(object sender, EventArgs e)
    {
        if (inc != 0)
        {
            inc = 0;
            NavigateRecords();
        }
        else
        {
            MessageBox.Show("Already on first employee.");
        }
    }

    /// <summary>
    /// Sets pointer (inc) to last row
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void btnLast_Click(object sender, EventArgs e)
    {
        if (inc != maxRows - 1)
        {
            inc = maxRows - 1;
            NavigateRecords();
        }
        else
        {
            MessageBox.Show("Already on last employee.");
        }
    }

    /// <summary>
    /// Main Navigation Method
    /// </summary>
    private void NavigateRecords()
    {
        dr = ds.Tables[0].Rows[inc];

        txtFirstName.Text = dr.ItemArray.GetValue(1).ToString();
        txtLastName.Text = dr.ItemArray.GetValue(2).ToString();
        txtJobTitle.Text = dr.ItemArray.GetValue(3).ToString();
        txtDepartment.Text = dr.ItemArray.GetValue(4).ToString();
    }

    /// <summary>
    /// Exit button handler
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void btnExit_Click(object sender, EventArgs e)
    {
        Application.Exit();
    }

    /// <summary>
    /// Add new record Button. Simply clears text fields, ready for a new record to be added.
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void btnAddNew_Click(object sender, EventArgs e)
    {
        txtFirstName.Clear();
        txtLastName.Clear();
        txtJobTitle.Clear();
        txtDepartment.Clear();

        btnAddNew.Enabled = false;
        btnSave.Enabled = true;
        btnCancel.Enabled = true;
    }

    /// <summary>
    /// Save a new record button
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void btnSave_Click(object sender, EventArgs e)
    {
        DataRow newRow = ds.Tables[0].NewRow();

        // newRow[0] is the id, thus its filled automatically
        newRow[1] = txtFirstName.Text;
        newRow[2] = txtLastName.Text;
        newRow[3] = txtJobTitle.Text;
        newRow[4] = txtDepartment.Text;

        ds.Tables[0].Rows.Add(newRow);

        try
        {
            objConnect.UpdateDB(ds);
            maxRows++;
            inc = maxRows - 1;

            MessageBox.Show("DB updated successfully");
        }
        catch (Exception err)
        {
            MessageBox.Show(err.Message);
        }

        btnAddNew.Enabled = true;
        btnSave.Enabled = false;
        btnCancel.Enabled = false;
    }

    /// <summary>
    /// Cancel new record button. Simply call NavigateRecords() method, and restores buttons.
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void btnCancel_Click(object sender, EventArgs e)
    {
        NavigateRecords();

        btnAddNew.Enabled = true;
        btnSave.Enabled = false;
        btnCancel.Enabled = false;
    }

}
}

这是DBconnection.cs代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SQLtest
{
/// <summary>
/// A class that makes the connection to the SQL Database
/// </summary>
class DBconnection
{
    // variables
    private string sql_string;
    private string strCon;
    System.Data.SqlClient.SqlDataAdapter da_1;

    // set methods
    public string Sql
    {
        set { sql_string = value; }
    }

    public string connection_string
    {
        set { strCon = value; }
    }

    // DataSet
    public System.Data.DataSet GetConnection
    {
        get { return MyDataSet(); }
    }

    // MyDataSet method
    private System.Data.DataSet MyDataSet()
    {
        System.Data.SqlClient.SqlConnection con = new System.Data.SqlClient.SqlConnection(strCon);
        con.Open();

        da_1 = new System.Data.SqlClient.SqlDataAdapter(sql_string, con);

        System.Data.DataSet dat_set = new System.Data.DataSet();
        da_1.Fill(dat_set,"Table_Data_1");

        con.Close();

        return dat_set;
    }

    // Update DB method
    public void UpdateDB(System.Data.DataSet ds)
    {
        System.Data.SqlClient.SqlCommandBuilder cb = new System.Data.SqlClient.SqlCommandBuilder(da_1);
        cb.DataAdapter.Update(ds.Tables[0]);
    }
}
}

编辑：

为了测试VS将DB.mdf复制到“ / bin / Debug”文件夹中，我添加了一条新记录，然后从服务器资源管理器中分离了DB，然后从“ / bin / Debug”文件夹中复制了DB.mdf并替换了主目录上的DB.mdf。项目文件夹。它证实了这可能是问题所在，因为现在我可以通过VS DB Designer看到新添加的记录。

现在，我只需要弄清楚如何在VS关闭时将对“ / bin / Debug”文件夹中的DB.mdf所做的更改更新到主项目DB.mdf。