怎么判定一个sqlconnection是open的

Question

我想用类似下面的方法：
if(!conn.isopen())
conn.open();

Answer 1

if (conn.State == ConnectionState.Closed)
{
    conn.Open();
}

Answer 2

conn.State = ConnectionState.Open

Answer 3

if (conn.State == ConnectionState.Closed) 
{ 
    conn.Open(); 
}
===========================================
同意1L

Answer 4

if (conn.State == ConnectionState.Closed)
{
conn.Open();
}

Answer 5

conn.State.Equals(System.Data.ConnectionState.Open)

Answer 6

if (conn.State == ConnectionState.Closed) 
{ 
    conn.Open(); 
}

Answer 7

这样判断未必强壮
在判断conn.State == ConnectionState.Closed前要先判断conn是否为空;

Answer 8

if(conn.State==ConnectionState.Closed)
{
conn.Open();
}

Answer 9

#region  打开数据库连接Open()
/// <summary>
/// 打开数据库连接.
/// </summary
private void Open() 
{
// 打开数据库连接
if (conn == null) 
{                conn = new SqlConnection(System.Configuration.ConfigurationManager.AppSettings["ConnectionString"]);
}
if(conn.State ==System.Data.ConnectionState.Closed)
conn.Open(); }

#endregion

Answer 10

conn.State = (conn.State==ConnectionState.Closed)? ConnectionState.Open:conn.state;