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C# Properties getting null values back instead of actual values

Posted on 2016-08-31
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Last Modified: 2016-08-31
I am trying to have a form which gets submitted and passes various text box parameters down along the way.  So I have properties in class for that with private strings (didn't use the auto-implemented properties but tried both).

Here is where the values originate from a WPF form:

            var exe = new DataReadWrite();
            var uv = new UserValues();

            uv.strFirstName = tbxFirstName.Text;
            uv.strLastName = tbxLastName.Text;
            uv.strEmailAddress = tbxEmailAddress.Text;

            exe.exeInsUser();

In the debugger the values above are populated...

Now when exeInsUser() chokes, it is due to the values being null as here:

separate class to hold the values:

    public class UserValues
    {
        private String firstname;
        private String lastname;
        private String emailaddress;

        public string strFirstName
        {
            get
            {
                return firstname;
            }

            set
            {
                firstname = value;
            }
        }

        public string strLastName
        {
            get
            {
                return lastname;
            }

            set
            {
                lastname = value;
            }
        }

        public string strEmailAddress
        {
            get
            {
                return emailaddress;
            }

            set
            {
                emailaddress = value;
            }
        }


The execution fails here with a null reference exception:

separate class to execute:

            var oPa = new DataParameters();
            var str = new UserValues();

            StoredProcParameter[] oPL = oPa.insUsersParm( str.strFirstName
                                                        , str.strLastName
                                                        , str.strEmailAddress);

I even tried implementing an interface (although the code above has this removed in the implementation) but everything is null!?

Any help is greatly appreciated!
0
Comment
Question by:cyimxtck
  • 3
5 Comments
 
LVL 20

Accepted Solution

by:
Daniel Van Der Werken earned 250 total points
ID: 41778733
You have to pass in the UserValues object, and I don't see that you are doing that.

For example:

            var exe = new DataReadWrite();
            var uv = new UserValues();

            uv.strFirstName = tbxFirstName.Text;
            uv.strLastName = tbxLastName.Text;
            uv.strEmailAddress = tbxEmailAddress.Text;

            exe.exeInsUser();

Open in new window


I don't see where exe is getting the uv values from. I would expect something similar to:

            var exe = new DataReadWrite();
            var uv = new UserValues();

            uv.strFirstName = tbxFirstName.Text;
            uv.strLastName = tbxLastName.Text;
            uv.strEmailAddress = tbxEmailAddress.Text;

            exe.exeInsUser(uv);

Open in new window


The exeInsUser() method would use the values from uv to populate the SQL parameters.
0
 

Author Comment

by:cyimxtck
ID: 41778752
I am not passing them right there I am getting them later in another routine from the UserValues.

In the bottom half of the original post:

separate class to execute:

            var oPa = new DataParameters();
            var str = new UserValues();

            StoredProcParameter[] oPL = oPa.insUsersParm( str.strFirstName
                                                        , str.strLastName
                                                        , str.strEmailAddress);
0
 

Author Comment

by:cyimxtck
ID: 41778757
public void exeInsUser()
        {
            insUsers();
        }
0
 
LVL 40

Assisted Solution

by:Kyle Abrahams
Kyle Abrahams earned 250 total points
ID: 41778801
var str = new UserValues();

You create a new object, and the properties don't have anything assigned to them at that point.

Either pass in a UserValue object

public void exeInsUser(UserValue uv)
        {
            insUsers(uv);
        }

Open in new window


as was suggested or move insUsers into the UserValue class, and reference the existing object.
0
 

Author Closing Comment

by:cyimxtck
ID: 41778826
Perfect!
0

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