Chapter 15 Error

leeWozyWarren · January 24th, 2012, 05:05 PM

I tried to make some changes but was getting no where so I decided to recreate the page complete with a new table with a reduced amount of text box's. I also remade the EF .edmx file from scratch. This time I get no wriggly lines under the code showing me that something doesn't work. The new page is called Test01.aspx.

I completed the initial Page_Load code and then tested it. It worked. The text boxes took data from the database correctly with no errors. Then I added the Button_Code and that is where it fell over when I tried to browse the page.

Below is the new code behind.

Code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using DistanceModel;

public partial class test01 : System.Web.UI.Page

{
    int _id = -1;
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!string.IsNullOrEmpty(Request.QueryString.Get("MileageId")))
        {
            _id = Convert.ToInt32(Request.QueryString.Get("MileageId"));
        }
        if (!Page.IsPostBack && _id > -1)
        {
            using (distanceEntities myEntities = new distanceEntities())
            {
                var Mileage = (from r in myEntities.Mileages
                               where r.MileageId == _id
                               select r).SingleOrDefault();
                if (Mileage != null)
                {
                    MondayTotal.Text = Mileage.M_To_Total.ToString();
                    TuesdayTotal.Text = Mileage.T_To_Total.ToString();
                    WednesdayTotal.Text = Mileage.W_To_Total.ToString();
                    ThursdayTotal.Text = Mileage.T_To_Total.ToString();
                }
            }
        }
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        using (distanceEntities myEntities = new distanceEntities())
        {
            
            Mileage myMileage;

            if (_id == -1) //Insert new item
            {
                myMileage = new Mileage();

                myEntities.AddToMileages(myMileage);
            }
            else // update new item
            {
                myMileage = (from r in myEntities.Mileages
                             where r.MileageId == _id
                             select r).Single();
            }

            myMileage.M_To_Total = Convert.ToInt32(MondayTotal.Text);
            myMileage.T_To_Total = Convert.ToInt32(TuesdayTotal.Text);
            myMileage.W_To_Total = Convert.ToInt32(WednesdayTotal.Text);
            myMileage.T_To_Total = Convert.ToInt32(ThursdayTotal.Text);

            myEntities.SaveChanges();
            Response.Redirect("Choose.aspx");
        }
    }
}

This is the error the browser shows:

Code:

Compilation Error 
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately. 

Compiler Error Message: CS1502: The best overloaded method match for 'DistanceModel.distanceEntities.AddToMileages(DistanceModel.Mileage)' has some invalid arguments

Source Error:

 

Line 45:                 myMileage = new Mileage();
Line 46: 
Line 47:                 myEntities.AddToMileages(myMileage);
Line 48:             }
Line 49:             else // update new item

...

leeWozyWarren · January 24th, 2012, 05:15 PM

Scratch that... I deleted the old files I have set up with the errors and it all now works... so far. I shall continue testing and come back if any further problems.

Thanks for your help again Imar :)

Imar · January 26th, 2012, 06:54 AM

Quote:

What is the difference between development and run-time?

Development time is the stuff you do in Visual Studio. There the error list gives you compilation and syntax errors. In order to compile and run the web site, you need to resolve all these errors.

Run-time errors are errors that occur when you view the page in the browser.

Cheers,
Imar

leeWozyWarren · January 29th, 2012, 01:22 PM

All working now - except for one thing which I wasn't expecting. I can go to my first page where I can choose a record and the query_string is passed to the next page where the EF picks it up and displays the content in my custom text_box's. I can also go direct to the page and fill in the details and when I click the save button it saves the new record. HOWEVER! If I don't complete all the fields, then it throws an error -

Here I input a number in the first text_box/field which is line 83. So it doesn't see an error for 83 and goes to 84 and doesn't find any data there!

Code:

Input string was not in a correct format. 
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.FormatException: Input string was not in a correct format.

Source Error: 


Line 82: 
Line 83:             myMileage.M_St_To_Miles = Convert.ToInt32(M_AM_FR_BOX.Text);
Line 84:             myMileage.M_Fi_To_Miles = Convert.ToInt32(TextBox4.Text);
Line 85:             myMileage.M_St_Fr_Miles = Convert.ToInt32(TextBox7.Text);
Line 86:             myMileage.M_Fi_Fr_Miles = Convert.ToInt32(TextBox8.Text);
 

Source File: c:\BegASPNET\mileage\test01.aspx.cs    Line: 84

I have checked the allow_nulls for the columns in the database and it is set to Yes. Here is my complete Code_Behind:

Code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using DistanceModel;

public partial class test01 : System.Web.UI.Page

{
    int _id = -1;
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!string.IsNullOrEmpty(Request.QueryString.Get("MileageId")))
        {
            _id = Convert.ToInt32(Request.QueryString.Get("MileageId"));
        }
        if (!Page.IsPostBack && _id > -1)
        {
            using (distanceEntities myEntities = new distanceEntities())
            {
                var Mileage = (from r in myEntities.Mileages
                               where r.MileageId == _id
                               select r).SingleOrDefault();
                if (Mileage != null)
                {
                    WeekEndingBox.Text = Mileage.Weekending.ToString();
                    M_AM_FR_BOX.Text = Mileage.M_St_To_Miles.ToString();
                    TextBox4.Text = Mileage.M_Fi_To_Miles.ToString();
                    TextBox7.Text = Mileage.M_St_Fr_Miles.ToString();
                    TextBox8.Text = Mileage.M_Fi_Fr_Miles.ToString();
                    
                    
                    T_AM_FR_BOX.Text = Mileage.T_St_To_Miles.ToString();
                    TextBox5.Text = Mileage.T_Fi_To_Miles.ToString();
                    TextBox9.Text = Mileage.T_St_Fr_Miles.ToString();
                    TextBox10.Text = Mileage.T_Fi_Fr_Miles.ToString();
                    
                    
                    W_AM_FR_BOX.Text = Mileage.W_St_To_Miles.ToString();
                    TextBox6.Text = Mileage.W_Fi_To_Miles.ToString();
                    TextBox11.Text = Mileage.W_St_Fr_Miles.ToString();
                    TextBox12.Text = Mileage.W_Fi_Fr_Miles.ToString();
                    
                    
                    TH_AM_FR_BOX.Text = Mileage.Th_St_To_Miles.ToString();
                    TextBox20.Text = Mileage.Th_Fi_To_Miles.ToString();
                    TextBox25.Text = Mileage.Th_St_Fr_Miles.ToString();
                    TextBox26.Text = Mileage.Th_Fi_Fr_Miles.ToString();
                    
                    
                    F_AM_FR_BOX.Text = Mileage.F_St_To_Miles.ToString();
                    TextBox22.Text = Mileage.F_Fi_To_Miles.ToString();
                    TextBox27.Text = Mileage.F_St_Fr_Miles.ToString();
                    TextBox28.Text = Mileage.F_Fi_Fr_Miles.ToString();
                    
                    //WeekEndingTotalBox.Text = Mileage.Week_Total.ToString();
                }
            }
        }
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        using (distanceEntities myEntities = new distanceEntities())
        {
            
            Mileage myMileage;

            if (_id == -1) //Insert new item
            {
                myMileage = new Mileage();

                myEntities.AddToMileages(myMileage);
            }
            else // update new item
            {
                myMileage = (from r in myEntities.Mileages
                             where r.MileageId == _id
                             select r).Single();
            }

            myMileage.M_St_To_Miles = Convert.ToInt32(M_AM_FR_BOX.Text);
            myMileage.M_Fi_To_Miles = Convert.ToInt32(TextBox4.Text);
            myMileage.M_St_Fr_Miles = Convert.ToInt32(TextBox7.Text);
            myMileage.M_Fi_Fr_Miles = Convert.ToInt32(TextBox8.Text);
            myMileage.T_St_To_Miles = Convert.ToInt32(T_AM_FR_BOX.Text);
            myMileage.T_Fi_To_Miles = Convert.ToInt32(TextBox5.Text);
            myMileage.T_St_Fr_Miles = Convert.ToInt32(TextBox9.Text);
            myMileage.T_Fi_Fr_Miles = Convert.ToInt32(TextBox10.Text);
            myMileage.W_St_To_Miles = Convert.ToInt32(W_AM_FR_BOX.Text);
            myMileage.W_Fi_To_Miles = Convert.ToInt32(TextBox6.Text);
            myMileage.W_St_Fr_Miles = Convert.ToInt32(TextBox11.Text);
            myMileage.W_Fi_Fr_Miles = Convert.ToInt32(TextBox12.Text);
            myMileage.Th_St_To_Miles = Convert.ToInt32(TH_AM_FR_BOX.Text);
            myMileage.Th_Fi_To_Miles = Convert.ToInt32(TextBox20.Text);
            myMileage.Th_St_Fr_Miles = Convert.ToInt32(TextBox25.Text);
            myMileage.Th_Fi_Fr_Miles = Convert.ToInt32(TextBox26.Text);
            myMileage.F_St_To_Miles = Convert.ToInt32(F_AM_FR_BOX.Text);
            myMileage.F_Fi_To_Miles = Convert.ToInt32(TextBox22.Text);
            myMileage.F_St_Fr_Miles = Convert.ToInt32(TextBox27.Text);
            myMileage.F_Fi_Fr_Miles = Convert.ToInt32(TextBox28.Text);
            
            myEntities.SaveChanges();
            Response.Redirect("Choose.aspx");
        }
    }
    protected void TextBox4_TextChanged(object sender, EventArgs e)
    {

    }
}

Any thoughts?

Regards

Lee

Imar · January 29th, 2012, 01:33 PM

The database is not the issue here. The code crashes when you use Convert.ToInt32 on an empty string.

Either make this field required using a Validator, or skip the conversion to an int when the TextBox contains null or an empty string.

Hope this helps,

Imar

leeWozyWarren · January 29th, 2012, 01:41 PM

Thanks Imar.

How would I do the skipping of the conversion if a Null was detected?

Lee

Imar · January 29th, 2012, 02:58 PM

You can use String.IsNullOrEmpty, like this:

Code:

if (!String.IsNullOrEmpty(yourControl.Text))
{
  yourEFObject.SomeProperty = Convert.ToInt32(yourControl.Text);
}
else
{
yourEFObject.SomeProperty = null; // if it's nullable, or some other default otherwise
}

Hope this helps,

Imar