Re: Error when importing a class dll - C# Discussion Boards

Re: Notifications in win c#

7-Aug-21 20:37

I coded this class:

public string dateText { get; set; }
       DateTime date;
       string[] formats = {"yyyy/MM/dd", "yyyy/M/d", "yy/MM/dd", "yy/M/d" };
       DateTime result;

       public bool CheckFormat()
       {
           if (!DateTime.TryParseExact(dateText, formats, CultureInfo.InvariantCulture,DateTimeStyles.None, out result))
           {
               return false;
           }
           else
           {
               return true;
           }
       }

Notifications in win c#

Member 149572104-Aug-21 17:35

Member 14957210

4-Aug-21 17:35

Notifications in win c#

OriginalGriff4-Aug-21 19:43

OriginalGriff

4-Aug-21 19:43

Nope, I don't get any.

This is not a good question - we cannot work out from that little what you are trying to do.
Remember that we can't see your screen, access your HDD, or read your mind - we only get exactly what you type to work with.

If you want help, you need to explain what you have tried, where you are stuck, and what help you need. Otherwise, we can't work out what the heck you are talking about and really can't help you.
Typing as little as possible mean you don't get useful answers!

"I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
"Common sense is so rare these days, it should be classified as a super power" - Random T-shirt
AntiTwitter: @DalekDave is now a follower!

Error when importing a class dll

Alex Dunlop3-Aug-21 22:42

3-Aug-21 22:42

Hi,
I have written a simple class for extracting numbers from a text:

using System;

namespace NumExtract
{
    public class Extraction
    {
        public string text { get; set; }//each chars can be added into an array using a[i]
        string b;
        public int value;

        public int NumberExtract()
        {
            //looping through all characters
            for (int i = 0; i < text.Length; i++)
            {
                if (char.IsDigit(text[i]))
                {
                    b += text[i];
                }
            }
            value = int.Parse(b);
            return value;
        }
    }
}

When I use this dll file as a reference in my project, this error appears:

Quote:
System.IO.FileNotFoundException: 'Could not load file or assembly 'System.Runtime, Version=4.2.2.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified.'

This error appears in Program.cs

static void Main()
       {
           Application.EnableVisualStyles();
           Application.SetCompatibleTextRenderingDefault(false);

           DevExpress.Skins.SkinManager.EnableFormSkins();
           DevExpress.UserSkins.BonusSkins.Register();

           Application.Run(new Form1());//Error happens in this line
       }

How can I fix it?

Richard Deeming3-Aug-21 23:44

Richard Deeming

3-Aug-21 23:44

Have you opened the folder instead of the project?
c# - Could not load file or assembly 'System.Runtime, Version=4.2.1.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' - Stack Overflow[^]

NB: Your code can be greatly simplified:

public static int ExtractNumber(string text)
{
    if (string.IsNullOrEmpty(text)) throw new ArgumentNullException(nameof(text));
    
    int result = 0;
    foreach (char c in text)
    {
        if (c >= '0' && c <= '9')
        {
            int digit = c - '0';
            result = checked(result * 10 + digit);
        }
    }
    
    return result;
}

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Alex Dunlop4-Aug-21 0:54

4-Aug-21 0:54

I have made a dll class library and imported it to my references in visual studio. I can use its namespace but it causes runtime error during the compiling.

Alex Dunlop4-Aug-21 8:44

4-Aug-21 8:44

Finally, I found the problem. I tried to use C# class library (NetFrameWork) instead of C# class library core.

Richard Deeming4-Aug-21 22:05

Richard Deeming

4-Aug-21 22:05

Yes, targeting can be quite complicated these days.

If the library targets .NET Framework, then it can be referenced by applications targeting any version of .NET Framework greater than or equal to the target version. But it cannot be referenced by applications targeting .NET Core or .NET 5/6.

If the library targets .NET Standard 2.0, then it can be referenced by applications targeting .NET Framework 4.6.1 or later, .NET Core 2.0 or later, or .NET 5/6. But you won't be able to use the new features introduced in .NET Core 3.0 or .NET 5/6.

If the library targets .NET Standard 2.1, then it can be referenced by applications targeting .NET Core 3.0 or later, or .NET 5/6. It cannot be referenced by applications targeting any version of .NET Framework. You will be able to use the new features introduced in .NET Core 3.0, but not those introduced in .NET Core 3.1 or .NET 5/6.

If the library targets .NET Core, then it can be referenced by that version of .NET Core, later versions of .NET Core, or .NET 5/6. It cannot be referenced by applications targeting any version of .NET Framework.

If it targets .NET 5, then it can only be referenced by applications targeting .NET 5/6.

This is Microsoft's idea of simplifying things! Sigh | :sigh:

.NET Standard | Microsoft Docs[^]

Oh, and there's also the option of multi-targeting, in case the above options weren't complicated enough:
Multi-targeting for NuGet Packages in your project file | Microsoft Docs[^]

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Richard MacCutchan4-Aug-21 1:31

Richard MacCutchan

4-Aug-21 1:31

Why such a complex piece of code to solve a simple problem?

public int NumberExtract()
{
    if (!Int32.TryParse(text, out value)
    {
        throw new FormatException("text is not a valid number");
    }
    return value;
}

Richard Andrew x644-Aug-21 7:29

Richard Andrew x64

4-Aug-21 7:29

Maybe the numerals exist inside text that also contains alpha characters.

The difficult we do right away...
...the impossible takes slightly longer.

Richard MacCutchan4-Aug-21 7:32

Richard MacCutchan

4-Aug-21 7:32

Maybe lots of things ...

Bohdan Stupak6-Aug-21 5:06

Bohdan Stupak

6-Aug-21 5:06

If you throw an exception when input is invalid you can use Parse instead

BillWoodruff8-Aug-21 20:30

BillWoodruff

8-Aug-21 20:30

If you think the problem is DevExpress related, try their (excellent) support forums.

public bool TryGetDigits(string str, out int iresult)
{
    StringBuilder sb = new StringBuilder
    (
        new string(str.Where(ch => Char.IsDigit(ch)).ToArray())
    );

    if (Int32.TryParse
    (
        sb.ToString(),
        out iresult)
    )
    {
        return true;
    }

    return false;
}

usage:

int iresult = 0;

bool gotSomeDigits = TryGetDigits("2ergtgwegwg1", out iresult);

if (gotSomeDigits )
{
    // use iresult
}
else
{
    // no digits
}

«The mind is not a vessel to be filled but a fire to be kindled» Plutarch

Richard Deeming8-Aug-21 21:20

Richard Deeming

8-Aug-21 21:20

I'm not sure why you've got the StringBuilder in there? You've already created the string you need and passed it into the constructor. Smile | :)

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Floating point conversion with error

BillWoodruff8-Aug-21 23:28

BillWoodruff

8-Aug-21 23:28

Richard Deeming wrote:
I'm not sure why you've got the StringBuilder in there?

Because little embroidered habanera peppers on old blue jeans is ... intriguing ?

«The mind is not a vessel to be filled but a fire to be kindled» Plutarch

Ismael Oliveira 20211-Aug-21 13:14

1-Aug-21 13:14

Hi.
I use C# in Visual Studio and SQL Server. In my form I have a label that receives the name of a bank and a Textbox that must be filed with the bank balance. This couple repeats for the number of bank accounts of the client. After I retrieve the balances, I use the following snipet:
            if (TabSaldo.Rows.Count > 0)
            {
                for (i = 0; i < Nbancos; i++)
                {
                    foreach (Control c1 in Gb_Bancos.Controls)
                    {
                        if (c1.Name.Contains("Lb_Banco" + (i + 1).ToString()))
                            c1.Text = LinhaSaldo[i].ItemArray[1].ToString();

                        if (c1.Name.Contains("Tb_Banco" + (i + 1).ToString()))
                        {
                            c1.Text = LinhaSaldo[i].ItemArray[2].ToString();
                            TotalBancos += float.Parse(LinhaSaldo[i].ItemArray[2].ToString()) / 100;
                        }
                    }
                }
            }
It's working fine, but when I make the conversion from string to float (line starting with (TotalBancos +=) the conversion ignores the decimal point. Example: if the balance is 113,54 it sums 11354. As you see, I had to include a division by 100, for it  to work. Please does anyone know what is wrong here?
Thanks.

OriginalGriff1-Aug-21 19:12

OriginalGriff

1-Aug-21 19:12

Why are you converting something to a string in order to parse it to a float?
Either it's a string to start with - in which case it's a waste of time and looks like the coder didn't know what he was doing - or it is a numeric value already - in which case why are you trying to parse it at all?

If I try to abstract your code:

float tb = 0.0F;
tb += float.Parse("666.66") / 100;
Console.WriteLine(tb);

Then I get what I expected: 6.6666 so there are a couple of possibilities:
1) LinhaSaldo[i].ItemArray[2] is not the value you expect it to be.
2) TotalBancos is not a floating point variable.
We can't check either of those so, it's going to be up to you.
Fortunately, you have a tool available to you which will help you find out what is going on: the debugger. If you don't know how to use it then a quick Google for "Visual Studio debugger" should give you the info you need.

Put a breakpoint on the first line in the function, and run your code through the debugger. Then look at your code, and at your data and work out what should happen manually. Then single step each line checking that what you expected to happen is exactly what did. When it isn't, that's when you have a problem, and you can back-track (or run it again and look more closely) to find out why.

Sorry, but we can't do that for you - time for you to learn a new (and very, very useful) skill: debugging!

Ismael Oliveira 20212-Aug-21 15:45

2-Aug-21 15:45

Hi, OriginalGriff.
I use debugging and the values retrieved are correct. The line

LinhaSaldo[i].ItemArray[2]

is used because of the code:

DataTable TabSaldo = Banco.LeSaldoBanco(Dtp_DataSaldo.Text);
DataRow[] LinhaSaldo = TabSaldo.Select(null, null, DataViewRowState.CurrentRows);

In this code I retrive data from the database and LinhaSaldo is used to access the data. The only form to do this that I know is by doing:

c1.Text = LinhaSaldo[i].ItemArray[2].ToString();

I've put messages to show me the retrieved values and they are OK, but after the line above, they are multiplied by 100. In other words, the decimal point was ignored. I´v tried many things, but none works. I also executed the program step by step, but nothing.
If you have any suggestion, I would apprecciate it.

Richard MacCutchan1-Aug-21 21:51

Richard MacCutchan

1-Aug-21 21:51

You should not use float or double types in financial applications, as they can lose precision. Use the Decimal type or convert all values to the smallest denomination (cents etc.) and use integers..

Ismael Oliveira 20212-Aug-21 15:59

2-Aug-21 15:59

Richard.
I changed the types. Thanks for your help.

jsc422-Aug-21 1:21

jsc42

2-Aug-21 1:21

Could, in addition to the ideas from the other respondents, be a culture thing. In some cultures, ',' is a thousands separator so your 113,54 could be treated as a misplaced thousands separator and assumed to be 11,354 which is 11354. If in your culture ',' is a decimal separator (which I am guessing is why you are dividing by 100 to get 113.54 [using my locale's decimal separator]) and your program is not using the same culture then it will misinterpret the value.

See, for example, c# - float.Parse() doesn't work the way I wanted - Stack Overflow[^]

See, for example, Single.Parse Method (System) | Microsoft Docs[^] (I know this is for single, rather than for float; but they work the same way and the version for float is playing hide-and-seek).

Ismael Oliveira 20212-Aug-21 15:58

2-Aug-21 15:58

Hi, jsc42.
I tried what you suggested and it aparently works.
Thanks.

Make a control invisible

Ismael Oliveira 202131-Jul-21 14:56