Input string was not in a correct format. Converting string to int

Question

Input string was not in correct form. I'm getting an exception on runtime as "System.FormatException".

Follwing lines shows exception-

public int Task 
{
    get
    { 
        return Int32.Parse(TaskText.Text);
    }
    set
    { 
        TaskText.Text = value.ToString(); 
    }
}

public int Project 
{
    get
    { 
        return Int32.Parse(ProjectText.Text);
    }
    set
    { 
        ProjectText.Text = value.ToString(); 
    }
}

I also tried -

Convert.ToInt32(TaskText.Text)
Convert.ToInt32(ProjectText.Text)

I need to pass these to following constructor,

Harvest_TimeSheetEntry entry = new Harvest_TimeSheetEntry(client,starttime,stoptime,task,project);

this constructor is stored in some class with task and project as integer parameters. And I can't change it because if i changed, it affects other code.

Do you know what's stored in TaskText.Text and ProjectText.Text? — Kamil Budziewski
– Kamil Budziewski, Commented Jul 22, 2013 at 10:39
I would make task and project(consider to follow .NET naming conventions, properties should be uppercased) to be Nullable<int> instead. So if the input is invalid you could return null. — Tim Schmelter
– Tim Schmelter, Commented Jul 22, 2013 at 10:41
But to pass these values to that constructor, I need these values to be integer. — Dinesh
– Dinesh, Commented Jul 22, 2013 at 10:42

Grant Thomas · Accepted Answer · 2013-07-22 10:39:14Z

3

It looks as though you're getting your input from controls accepting user input, which is just asking for failure, since a user can potentially enter something that doesn't represent an integer value. You can use TryParse to avoid this:

var result = 0;
if (int.TryParse(TaskText.Text, out result)) {
  return result;
}
return 0;

So, if the value of TaskText.Text == "1", this will succeed; if the value of TaskText.Text == "aaaa", this will fail - and return zero. You example would raise the appropriate exception, as experienced.

However, an exception might be the right thing to happen here, if you can't handle a bad value, don't have an alternative, and the application relies on the input to move forward. More likely, you could do with some validation on your input fields to prevent bad data being submitted.

answered Jul 22, 2013 at 10:39

Grant Thomas

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Comments

Vanlalhriata · Accepted Answer · 2013-07-22 12:17:36Z

0

Since your Harvest_TimeSheetEntry constructor expects task and project to be integers, you must have a list of integers that correspond to the different tasks and projects. Now you can't expect Int32 to know which task corresponds to which number, can you?

I would suggest you use ComboBoxes for TaskText and ProjectText. Then, you can assign the correct corresponding integer to each ComboBoxItem.Tag.

Please note that this goes far beyond the kind of answers you should expect from SO.

edited Jul 22, 2013 at 12:17

answered Jul 22, 2013 at 11:29

Vanlalhriata

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3 Comments

Dinesh Over a year ago

Ok. I'll try by this way.

Dinesh Over a year ago

I tried by using comboboxes, but it still shows the same exception.

Vanlalhriata Over a year ago

This is a classic case of shotgun debugging. Once again, you are getting the exception because of the way you are trying to use Parse. Have you even looked it up?

blindmeis · Accepted Answer · 2013-07-22 12:24:37Z

0

if you do not use MVVM or binding you can simply do the check before your need it. t

 int task;
 int project;

 if(!Int32.TryParse(TaskText.Text, out task))
 {}       //errorhandling here

 if(!Int32.TryParse(ProjectText.Text, out project))
 {}//errorhandling here

 //all fine
 var entry = new Harvest_TimeSheetEntry(client,starttime,stoptime,task,project);

answered Jul 22, 2013 at 12:24

blindmeis

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Comments

Ikado · Accepted Answer · 2013-07-22 10:40:23Z

-1

You must check if you can parse it into Integer

try

Int32 foo =0;
if (Int32.TryParse(TaskText.Text, out foo))
{
    return foo;
}

answered Jul 22, 2013 at 10:40

Ikado

113 bronze badges

1 Comment

Trevor Pilley Over a year ago

If it parses, foo will contain the value, no need to then call convert too.

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