单击更新按钮时，C＃update语句不会更新

Question

我正在创建c＃项目到目前为止插入和删除按钮正在工作但是当我点击更新按钮它给出的数据尚未更新，我无法看到我的代码有什么问题请帮助

public bool Update(Classre c)
{
    bool isSuccess = false;
    SqlConnection conn = new SqlConnection(myconnstring);

    try
    {
        string sql = "UPDATE Class SET ClassName=@ClassName,ClassLevel=@ClassLevel WHERE ClassID=@ClassID";
        SqlCommand cmd = new SqlCommand(sql, conn);
        cmd.Parameters.AddWithValue("@ClassName", c.ClassName);
        cmd.Parameters.AddWithValue("@ClassLevel", c.ClassLevel);
        conn.Open();
        int rows = cmd.ExecuteNonQuery();

        if (rows > 0)
        {
            isSuccess = true;
        }
        else
        {
            isSuccess = false;
        }
    }
    catch (Exception ex)
    {

    }
    finally
    {
        conn.Close();
    }

    return isSuccess;
}

这是我的更新按钮代码，我调用保存更新代码的类

private void button3_Click(object sender, EventArgs e)
{
    c.ClassID = int.Parse(textBox1.Text); 
    c.ClassName = textBox2.Text;
    c.ClassLevel = comboBox1.Text;

    bool success = c.Update(c);
    if (success == true)
    {
       // label4.Text = "Data Has been updated";
        MessageBox.Show("Data Has been updated");
        DataTable dt = c.Select();
        dataGridView1.DataSource = dt;

    }
    else
    {
        //label4.Text = "Data Has not been updated";
        MessageBox.Show("Data Has not been updated");

    }
}

Answer 1

我宁愿使用存储过程而不是通过sql，但你可以大大简化这一点。如上所述，你的try / catch比没有一个更差，因为它压制了错误。

public bool Update(Classre c)
{
    USING(SqlConnection conn = new SqlConnection(myconnstring))
    {
        string sql = "UPDATE Class SET ClassName = @ClassName, ClassLevel = @ClassLevel WHERE ClassID = @ClassID";

        USING(SqlCommand cmd = new SqlCommand(sql, conn))
        {
            cmd.Parameters.Add("@ClassName", SqlDbType.VarChar, 4000).Value = c.ClassName;
            cmd.Parameters.Add("@ClassLevel", SqlDbType.Int).Value = c.ClassLevel;
            cmd.Parameters.Add("@ClassID", SqlDbType.Int).Value = c.ClassID;
            conn.Open();
            int rows = cmd.ExecuteNonQuery();
            return rows > 0;
        }
    }
}