Cfrgtkky

I need to check if an input is valid prior to updating my db.

I have created a bool method to check if it is valid.

private bool validProject(string ProjectID)

{

    using (AXEntitiesDEV db = new AXEntitiesDEV())

    {

        return db.PROJTABLEs.Any(c => c.PROJID==ProjectID);



    }

}

and am checking it in my update method.

 protected void Insert(object sender, EventArgs e)

    {

        using (GPSE2Entities entities = new GPSE2Entities())

        {

            TextBox txtEditTime = (TextBox)gvDailyGPS.FooterRow.FindControl("txtFooterTime");

            DropDownList ddlEventDateOnly = (DropDownList)gvDailyGPS.FooterRow.FindControl("ddlFooterDateOnly");

            DateTime EDT = DateTime.Now;

            TextBox txtAddProjectID = (TextBox)gvDailyGPS.FooterRow.FindControl("txtAddProjectID");

            validProject(txtAddProjectID.Text);

            DailyGPSTable newLOB = new DailyGPSTable

                {

                    EventDateTime = EDT,

                    Project = txtAddProjectID.Text,

                };



                entities.DailyGPSTables.Add(newLOB);

                {

                    entities.SaveChanges();

                    BindGrid();

                }

                entities.SaveChanges();

            }

    }

I tried catching and reporting the error but it allows invalid input through when false.

try

{

    validProject(txtAddProjectID.Text);

}

catch (ArgumentException)

{

    addErr.Text = "";



    addErr.Text = "Invalid Project ID.";

}

What's the best way I can catch and report the error prior to trying the insert?

You can throw your own exception:

try

{

    if (!validProject(txtAddProjectID.Text))

        throw new ArugmentExceptioN(txtAddProjectID.Text);

}

catch (ArgumentException)

{

    addErr.Text = "";

    addErr.Text = "Invalid Project ID.";

}

But don't do that!

You already have a boolean telling you the function failed. Just use that with a normal if block:

if (!validProject(txtAddProjectID.Text))

{

    addErr.Text = "";

    addErr.Text = "Invalid Project ID.";

}

this is only one of many conditions that must be met prior to updating the db

There's still no need for an exception.

bool validRecord = true;



validRecord = validRecord && validProject(txtAddProjectID.Text);

validRecord = validRecord && someOtherCheck();

validRecord = validRecord && someFinalCheck();

validRecord = validRecord && howEverManyYouNeed();



if (!validRecord)

{

    ShowError();

}

else

{

    UpdateDB();

}

You can do a similar thing by just appending to a string or adding to a list that starts out empty. At the end, if the item has any length, show the errors.

try

{

  validProject(txtAddProjectID.Text);

}

catch (ArgumentException e)

{

  addErr.Text = "";



  addErr.Text = e.Message;

}





private static void validProject(object text)

{

  throw new ArgumentException($"Invalid Project ID.{text}");

}

Just check the result of the call to validProject and throw an exception if it returns false:

try

{    

    if (!validProject(txtAddProjectID.Text))

        throw new ArgumentException("Argument is invalid", nameof(txtAddProjectID.Text));

}

catch (ArgumentException)

{

    addErr.Text = "";



    addErr.Text = "Invalid Project ID.";

}