C＃收盘SqlConnection和SqlDataReader的或不？ [英] c# closing sqlconnection and sqldatareader or not?

问题描述

我有这样一段代码：

SqlConnection conn;
string strconString = System.Configuration.ConfigurationManager.ConnectionStrings["SQLCONN"].ToString();
conn = new SqlConnection(strconString);
string cmdstr = "select status from racpw where vtgid = " + vtgid;
SqlCommand cmdselect = new SqlCommand(cmdstr, conn);
conn.Open();
SqlDataReader dtr = cmdselect.ExecuteReader();
if (dtr.Read())
{
return;
}
else
{
...
}
dtr.Close();
conn.Close();

现在我的问题是。
。如果回报，确实我的连接和DTR都会自动关闭，或者我应该使用一个布尔变量和我的连接得到关闭后执行的回报？

Now my question is. If return, does my connection and dtr get closed automatically or should I use a bool variable and perform a return after my connections get closed?

推荐答案

您必须关闭返回之前的连接。
中的最好的办法是使用块，因为的SqlConnection实现了IDisposable接口。在这种情况下，你不必记住，你必须关闭，即使异常被抛出连接

You have to close connection before return. The best way to do it is USING block, because SqlConnection implements IDisposable interface. In that case you don't have to keep in mind that you have to close connection even if exception was thrown.

请参阅下面的例子：

using (var conn = new SqlConnection(strconString))
{
    string cmdstr = 
        "select status from racpw where vtgid = " + vtgid;
    using (var cmdselect = new SqlCommand(cmdstr, conn))
    {
        conn.Open();
        using(var dtr = cmdselect.ExecuteReader())
        {
            if (dtr.Read())
            {
                return;
            }
            else
            {
                ...
            }
        }
    }
}

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