c# - 如何在多个实例中使用Using语句？

我想对using和SqlConnection对象使用SqlCommand来处理它们。在这种情况下如何使用？

例如：

using (sqlConnection = new SqlConnection(IRLConfigurationManager.GetConnectionString("connectionStringIRL")))
{
}

但是在这里我使用基于if条件的连接。

SqlConnection _sqlConnection;
SqlCommand sqlCmd;
DBPersister per = (DBPersister)invoice;
if (per == null)
{
    _sqlConnection = new SqlConnection(IRLConfigurationManager.GetConnectionString("connectionStringIRL"));
    sqlCmd = new SqlCommand("usp_UpdateDocumentStatusInImages", _sqlConnection);
}
else
{
    _sqlConnection = per.GetConnection();
    sqlCmd = per.GenerateCommand("usp_UpdateDocumentStatusInImages", _sqlConnection, per);
}

sqlCmd.CommandType = CommandType.StoredProcedure;
//mycode

try
{
    if (_sqlConnection.State == ConnectionState.Closed)
        _sqlConnection.Open();
    sqlCmd.ExecuteNonQuery();
}
catch
{
    throw;
}
finally
{
    if (per == null)
        invoice._sqlConnection.Close();
}

最佳答案

您可以像这样嵌套它们：

using (var _sqlConnection = new SqlConnection(...))
{
    using (var sqlCmd = new SqlCommand(...))
    {
        //code
    }
}