从我之前的问题中，我已经解决了如何显示 MS Access DB 文件中的信息。问题是，在我删除了一些用作示例尝试的条目后，序列号变得混乱，现在项目的 ID 乱序。这是它现在的样子，然后是我的代码。
=== Magazine 1 ===
People
Times Inc.
4.95
19.95
=== Magazine 2 ===
Car and Driver
Hachetter Inc.
3.95
19.99
=== Magazine 7 ===
a
b
1
2
按钮事件（我怀疑是代码错误）：
private void btnShowMags_Click(object sender, EventArgs e)
{
// Creating new instance of the DisplayMags form.
DisplayMags displayMags = new DisplayMags();
// find the path where the executable resides
string dbPath = Application.StartupPath;
// Providing a path to the MS Access file.
string connString = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source="
+ dbPath + @"\..\..\..\..\Magazines.mdb; User Id=admin; Password=";
// Creating a new connection and assigning it to a variable.
OleDbConnection conn = new OleDbConnection();
conn.ConnectionString = connString;
// Creating a new instance for a command which we will use later.
OleDbCommand cmd = new OleDbCommand();
cmd.Connection = conn;
// declare and instantiate the command
OleDbCommand cmdMagazines = new OleDbCommand();
cmdMagazines.CommandText = "select * from magazine";
cmdMagazines.Connection = conn;
OleDbDataReader drMagazines;
try
{
// open the connection
conn.Open();
// retrieve data from the data source to the data reader
drMagazines = cmdMagazines.ExecuteReader();
if (drMagazines.HasRows)
{
while (drMagazines.Read())
{
displayMags.txtDisplayMags.Text += "=== Magazine " +
drMagazines.GetValue(0) + " ===" + Environment.NewLine +
drMagazines.GetValue(1) + Environment.NewLine +
drMagazines.GetValue(2) + Environment.NewLine +
drMagazines.GetValue(3) + Environment.NewLine +
drMagazines.GetValue(4) + Environment.NewLine +
Environment.NewLine;
}
}
}
catch (Exception ex)
{
// Displaying any errors that might have occured.
MessageBox.Show("Error opening the connection: " + ex.Message);
}
finally
{
// Closing connection after task was completed.
conn.Close();
}
// Displaying DisplayMags form, assuring that earlier form
// will not be accessible. Show() let us access all forms.
displayMags.ShowDialog();
}
如何使序列号按顺序显示？
编辑我将以这种方式计算所有条目：
try
{
// open the connection
conn.Open();
// retrieve data from the data source to the data reader
drMagazines = cmdMagazines.ExecuteReader();
int i = 0;
if (drMagazines.HasRows)
{
while (drMagazines.Read())
{
i++;
displayMags.txtDisplayMags.Text += "=== Magazine " +
i + " ===" + Environment.NewLine +
drMagazines.GetValue(1) + Environment.NewLine +
drMagazines.GetValue(2) + Environment.NewLine +
drMagazines.GetValue(3) + " / issue" + Environment.NewLine +
drMagazines.GetValue(4) + " / year" + Environment.NewLine +
Environment.NewLine;
}
}
}