Validate input multiple textboxes

Question

I'm reading data and setting fields in another method with this method, is it possible to validate that each field is not empty or contains other than numbers?

I wanna be able to display one messagebox "Fill in all textboxes" Currently if I add an elsemethod for each I get (in worst case 4 messageboxes)..

    private bool ReadInput()
    {
        double curReading = 0;
        double prevReading = 0;
        double amount = 0;
        double unitNumber = 0;

        if (double.TryParse(tbReading.Text, out curReading))
        {
            CalcData.SetCurrentReading(curReading);
        }

        if (double.TryParse(tbPrevReading.Text, out prevReading))
        {
            CalcData.SetPrevReading(prevReading);
        }

        if (double.TryParse(tbAmount.Text, out amount))
        {
            CalcData.SetAmount(amount);
        }

        if (double.TryParse(tbUnitNumber.Text, out unitNumber))
        {
            CalcData.SetUnitNumber(unitNumber);
        }
        return false;
    }

Take a look at: [Validation using Validating event and ErrorProvider - Show Error Summary](http://stackoverflow.com/a/33080822/3110834) — Reza Aghaei, Sep 26 '16 at 19:01
Also to know more options about windows forms validation, take a look at this post: [Validating user input / Give .NET controls status OK or NOK](http://stackoverflow.com/a/35993185/3110834) — Reza Aghaei, Sep 26 '16 at 19:03

score 2 · Accepted Answer · answered Sep 26 '16 at 15:53

Something like this maybe:

private bool ReadInput()
{
    double curReading = 0;
    double prevReading = 0;
    double amount = 0;
    double unitNumber = 0;
    var validData = true;

    if (double.TryParse(tbReading.Text, out curReading))
    {
        CalcData.SetCurrentReading(curReading);
    }
    else
    {
        validData = false;
    }

    if (double.TryParse(tbPrevReading.Text, out prevReading))
    {
        CalcData.SetPrevReading(prevReading);
    }
    else
    {
        validData = false;
    }

    if (double.TryParse(tbAmount.Text, out amount))
    {
        CalcData.SetAmount(amount);
    }
    else
    {
        validData = false;
    }

    if (double.TryParse(tbUnitNumber.Text, out unitNumber))
    {
        CalcData.SetUnitNumber(unitNumber);
    }
    else
    {
        validData = false;
    }

    if(!validData)
    {
        //Show your dialog here
    }

    return false;
}

Cheers, just realized I could fix it that way too :) – noxious Sep 26 '16 at 15:55 — noxious, Sep 26 '16 at 15:55

Validate input multiple textboxes

1 Answers1