捕获到无效的操作异常 [英] Invalid Operation Exception was caught

问题描述

你好

如果BD中的记录存在于脸颊功能正常的情况下，我会为脸颊编写一个函数，但是在执行插入代码时我会点击（Click（object sender，EventArgs e）按钮以下错误

错误：connectionString属性尚未初始化。

如果我不使用脸颊功能我在按钮的Click事件中插入代码

当我使用脸颊功能时会发生这个错误，

我的脸颊功能代码

Hello
I write a function for cheek if the records exists in BD the cheek function working right,but in the (Click(object sender, EventArgs e) button when execute the insert code I face to below error
Error:The connectionString property has not been initialized.
If I don’t use from cheek function my insert code in the Click event of button working right
When I use from cheek function this error happen,
My cheek function code

public bool EducationfieldExiste()
{
        SqlCommand cmdchek = new SqlCommand("ChekRecordExist", con);
        cmdchek.CommandType = CommandType.StoredProcedure;
        int ID = Convert.ToInt32(Session["PersonID"].ToString());
        cmdchek.Parameters.AddWithValue("@PersonID", ID.ToString());
        cmdchek.Parameters.AddWithValue("@FieldID", DropDownList_PersonField.SelectedValue.ToString());
        cmdchek.Parameters.AddWithValue("@SubFieldID", DropDownList_PersonSubField.SelectedValue.ToString());
        cmdchek.Parameters.AddWithValue("@Degree", DropDownList_PersonDegree.SelectedValue.ToString());
        cmdchek.Connection = con;
        try
        {
            con.Open();
            SqlDataReader read;
            read = cmdchek.ExecuteReader();
            if (read.HasRows)
            {

                return true;
            }
            else
            {
                return false;

            }
        }
        catch (Exception)
        {

            throw;
        }
        finally
        {
            con.Dispose();
            con.Close();
        }
}

我在事件按钮中的插入代码

My insert code in event button

protected void ButtonEducationDgree_Click(object sender, EventArgs e)
{
    if (EducationfieldExiste() == true) //--------- this condition working right
    {
        Degreeexist.Visible = true;
    }
    else
    {
            SqlCommand cmd2 = new SqlCommand("Insert_Education_Degree_TB", con);
            cmd2.CommandType = CommandType.StoredProcedure;
            cmd2.Parameters.AddWithValue("@Person_ID", Session["PersonID"].ToString());
            cmd2.Parameters.AddWithValue("@Field_ID", DropDownList_PersonField.SelectedValue.ToString());
            cmd2.Parameters.AddWithValue("@SubField_ID", DropDownList_PersonSubField.SelectedValue.ToString());
            cmd2.Parameters.AddWithValue("@Degree_Education", DropDownList_PersonDegree.SelectedValue.Trim());
            cmd2.Parameters.AddWithValue("@University_Name", TextBox_UniversityNmae.Text.Trim());
            cmd2.Parameters.AddWithValue("@Data_Graduated", TextBox_DateGraduated.Text.Trim());
            cmd2.Parameters.AddWithValue("@Experience_Job", DropDownList_Experience.SelectedValue);
            try
            {
                con.Open();
                cmd2.ExecuteNonQuery();
                cmd2.Parameters.Clear();
                Labelsucces.Visible = true;
                Labelsucces.Text = "Insert Education was Sucsessfuly";
                TextBox_UniversityNmae.Text = "";
                TextBox_DateGraduated.Text = "";
                LblErorr.Visible = false;
            }
            Catch //----------Here is the Error
            {

                LblErorr.Visible = true;
                LblErorr.Text = "Insert Education was failed try again";
                Labelsucces.Visible = false;

            }
            finally
            {
                con.Close();
                con.Dispose();
            }//--------------------11111111111111111111--------------

    }//------------------- end of else cheekrecord

}//--------end of Btton Education

请帮助我谢谢

Please help me thanks

推荐答案

如果它说connectionString属性还没有初始化。然后很明显为什么：

当你运行 EducationfieldExiste 方法时，它总是这样做：

If it's saying that "The connectionString property has not been initialized." then it's pretty obvious why:
When you run your EducationfieldExiste method it always does this:

finally
{
    con.Dispose();
    con.Close();
}

因此，当您尝试立即再次使用相同的连接对象时：

So when you try to use the same connection object again immediately:

if (EducationfieldExiste() == true) //--------- this condition working right
{
    Degreeexist.Visible = true;
}
else
{
    SqlCommand cmd2 = new SqlCommand("Insert_Education_Degree_TB", con);
    ...

con SqlConnection对象已被销毁 - 您无法再次使用它。



更改代码以仅在完成连接时关闭连接，或者每次都创建新连接（并处理它）。

the con SqlConnection object has been destroyed - you can't use it again.

Either change your code to close the connection only when you are finished with it, or create a new connection (and dispose it) each time.

I已通过此代码解决了错误

I've solved the error by this code

if (con.State == ConnectionState.Open)
            {
                con.Close();
            }

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