Question

我目前收到的错误是： System.InvalidOperationException：'ConnectionString属性尚未初始化。' 我想要一些帮助来解决这个问题，因为我试图将数据从c＃表单（多个文本框）输入到SQL数据库表格，我当前的代码是

 private void AcceptData()
    {
        using (Connection = new SqlConnection(connectionString))
        using (SqlDataAdapter adapter = new SqlDataAdapter("INPUT INTO Person", Connection))//, Connection
        {
            DataTable RegisterTable = new DataTable();
            adapter.Fill(RegisterTable); //System.InvalidOperationException: 'The ConnectionString property has not been initialized.' TO FIX

            string name = textBox1.Text;
            string organisation = textBox3.Text;
            DateTime Time = DateTime.Parse(textBox2.Text);
            string strDateTimeIn = Time.ToString("yyyy-MM-dd HH:mm:ss.ffff");
            string query = "INSERT INTO Person (Name,Organisation,TimeIn) VALUES('" + name + "','" + organisation + "','" +strDateTimeIn+ "')";
            SqlCommand SignIn = new SqlCommand(query,Connection);
            SignIn.ExecuteNonQuery();
        }

    }

任何帮助将不胜感激

使用的连接字符串是：string connectionString = (@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Register.mdf;Integrated Security=True");

Answer 1

您需要打开连接

using (Connection = new SqlConnection(connectionString))
{
    connection.Open();

    using (SqlDataAdapter adapter = new SqlDataAdapter("INPUT INTO Person", Connection))//, Connection
        {
            DataTable RegisterTable = new DataTable();
            adapter.Fill(RegisterTable); //System.InvalidOperationException: 'The ConnectionString property has not been initialized.' TO FIX

            string name = textBox1.Text;
            string organisation = textBox3.Text;
            DateTime Time = DateTime.Parse(textBox2.Text);
            string strDateTimeIn = Time.ToString("yyyy-MM-dd HH:mm:ss.ffff");
            string query = "INSERT INTO Person (Name,Organisation,TimeIn) VALUES('" + name + "','" + organisation + "','" +strDateTimeIn+ "')";
            SqlCommand SignIn = new SqlCommand(query,Connection);
            SignIn.ExecuteNonQuery();
        }
}

Answer 2

“尚未初始化ConnectionString属性”清楚地表明在方法内未正确分配用于打开SqlConnection的连接字符串属性。要解决此问题，请在方法体中分配连接字符串，如下所示：

private void AcceptData()
{
    // assumed the connection string obtained from app.config or web.config file
    string connectionString = ConfigurationManager.ConnectionStrings["ConnectionStringName"].ConnectionString;
    using (SqlConnection Connection = new SqlConnection(connectionString))
    {
        Connection.Open(); // open the connection before using adapter
        using (SqlDataAdapter adapter = new SqlDataAdapter("INPUT INTO Person", Connection))
        {
            // other stuff
        }
    }

    // other stuff
}

或者将连接字符串作为方法参数传递：

private void AcceptData(string connectionString)
{
    using (SqlConnection Connection = new SqlConnection(connectionString))
    {
        Connection.Open(); // open the connection before using adapter
        using (SqlDataAdapter adapter = new SqlDataAdapter("INPUT INTO Person", Connection))
        {
            // other stuff
        }
    }

    // other stuff
}

参考文献：

How to fix "The ConnectionString property has not been initialized"

C# Database The ConnectionString property has not been initialized

'ConnectionString属性尚未初始化。'修理

2 个答案: