using (Font font3 = new Font("Arial", 10.0f), 
           font4 = new Font("Arial", 10.0f))
{
    // Use font3 and font4.
}

我是這樣理解的在Page_Load下連線SQL Server 2005

string connectionString = "server=localhost;database=Northwind;integrated security=SSPI";
SqlConnection mySqlConnection = new SqlConnection(connectionString);
using (mySqlConnection) 
{
mySqlConnection.Open();
lblInfo.Text = "＜b＞mySqlConnection物件的ConnectionString屬性為：＜b＞" +
mySqlConnection.ConnectionString + "＜br＞";
lblInfo.Text += "＜b＞mySqlConnection物件的ConnectionTimeout屬性為＜b＞" +
mySqlConnection.ConnectionTimeout + "＜br＞";
lblInfo.Text += "＜b＞mySqlConnection物件的Database屬性為＜b＞" +
mySqlConnection.Database + "＜br＞";
lblInfo.Text += "＜b＞mySqlConnection物件的DataSource屬性為＜b＞" + 
mySqlConnection.DataSource + "＜br＞";
lblInfo.Text += "＜b＞mySqlConnection物件的ServerVersion屬性為＜b＞" + 
mySqlConnection.ServerVersion + "＜br＞";
lblInfo.Text += "＜b＞mySqlConnection物件的當前狀態為＜b＞"+
mySqlConnection.State + "＜br＞";
}
lblInfo.Text += "＜br＞＜b＞關閉連線後的mySqlConnection物件的狀態為：＜/b＞";
lblInfo.Text += mySqlConnection.State.ToString();

這樣就不用寫

try{}

catch(Exception e){}

finally{}

顯示的關閉資料連線 在超過using的範圍會自動關閉