C#出现8个错误，帮忙改一下，谢谢

Question

using System.Data.SqlClient;

namespace WindowsFormsApplication4
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

    private void button1_Click(object sender, EventArgs e)
    {
        try 
        {
            string connectionString="Server=(local);Integrated Security=SSPI;Database=student";
            SqlConnection sqlCnn=new SqlConnection（connectionString);
            sqlCnn.Open();
            MessageBox.Show("连接成功!");
        }
        catch(SqlException  ex)
        {
            MessageBox.Show(ex.Message);
        }


    }
}

}

Answer 1

string connectionString="Server=(local);Integrated Security=SSPI;Database=student;uid=?;pwd=?";

SqlConnection sqlCnn=new SqlConnection（connectionString); 全角括号