Re: using usage (IDisposable) - C# Discussion Boards

22-Mar-15 14:22

Message Closed

modified 24-Mar-15 18:15pm.

Richard Deeming23-Mar-15 3:17

23-Mar-15 3:17

You should never catch the general "Exception" type, except in the entry point to your application where you simply log the exception and exit.

In the OP's code, the try..catch block isn't needed, since there are TryParse methods which won't throw an exception if the input is invalid.

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

Message Closed

23-Mar-15 4:21

23-Mar-15 4:21

Message Closed

modified 24-Mar-15 18:15pm.

Richard Deeming23-Mar-15 4:26

23-Mar-15 4:26

Gerry Schmitz wrote:
You have no idea what he has "higher up".

Doesn't matter - swallowing every exception "just-in-case" is still a bad idea.

Gerry Schmitz wrote:
You also can't seem to tell the difference between "Parse" and "TryParse".

What?! I suggest you try reading my comments again.

Gerry Schmitz wrote:
You should "never" shoot your mouth off before thinking.

Talking to yourself is the first sign of madness.

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

Message Closed

23-Mar-15 4:30

23-Mar-15 4:30

Message Closed

modified 24-Mar-15 18:15pm.

Richard Deeming23-Mar-15 4:34

23-Mar-15 4:34

Which will throw an exception when the input cannot be parsed.

Which is why I suggested using TryParse, which doesn't throw an exception.

Which would then mean that he wouldn't need a try..catch block to catch the exception from the Parse method.

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

Message Removed

23-Mar-15 4:49

23-Mar-15 4:49

Message Removed

modified 24-Mar-15 18:15pm.

Richard Deeming23-Mar-15 3:28

SQLite encryption types for data

23-Mar-15 3:28

As others have said, the code you've posted will work as expected.

However, you can avoid the try..catch block by using the TryParse methods. You should also check the result of line.Split(';') to avoid an IndexOutOfRangeException, check that the second field is a valid Enum value, and check that the dictionary doesn't already contain the key:

string[] fields = line.Split(';');
if (fields.Length < 5) return false;

// TODO: Give these variables proper names:
long f0;
int f1, f3, f4;

if (!long.TryParse(fields[0], out f0)) return false;
if (!int.TryParse(fields[1], out f1)) return false;
if (!int.TryParse(fields[3], out f3)) return false;
if (!int.TryParse(fields[4], out f4)) return false;

// If the dictionary already contains the key, the Add method throws an ArgumentException:
if (prodFileIndexDic.ContainsKey(f0)) return false; 

// Any integer can be cast to any enum without an exception;
// you probably wany to check that it's valid first:
if (!Enum.IsDefined(typeof(ProdKategoriEnum), f1)) return false;

prodList.Add(new Produkt(f0, (ProdKategoriEnum)f1, fields[2], f3, f4));
prodFileIndexDic.Add(f0, lineIndex);
lineIndex++;

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

DPaul199422-Mar-15 6:03

DPaul1994

22-Mar-15 6:03

I have an application in C# which uses a SQLite database. In this database I have a table where I inserted a value encrypted with sha1, via sql query. Te problem is that I want to select that data and use it like:

cmd.CommandText = "Select * from accounts where (username=@username and password=sha1(@password));";
cmd.Parameters.AddWithValue("@password", password);

cmd.CommandText = "Select * from accounts where (username=@username and password=@password);";
cmd.Parameters.AddWithValue("@password", sha1(password));

But from what I heard, I can't use sha1 like this, I have to use a function like this one, but it doesn't work:

string sha1(string password) {
            byte[] byteArray = Encoding.UTF8.GetBytes(password);
            return Convert.ToBase64String(sha1.ComputeHash(byteArray);
        }

I receive error:

sha1(string) is a method, which is not valid in the given context

The other thing, I heard about KDF ( key definition function) which it seems to be a better encryption type but I don't really know how to use it. Can anybody help me with that?

modified 22-Mar-15 12:11pm.

Richard MacCutchan22-Mar-15 6:12

Richard MacCutchan

22-Mar-15 6:12

See Secure Password Authentication Explained Simply[^].

You need to show some more of your code, to show why the context is incorrect as you have coded it. Where exactly does the error message appear?

modified 22-Mar-15 13:00pm.

manchanx22-Mar-15 6:42

manchanx

22-Mar-15 6:42

Note he wrote "encryption" but meant "hashing" (sha1). I can't help him with that regarding SQLite but maybe you can add something to your answer.

Recursion: see Recursion.

DPaul199422-Mar-15 7:14

DPaul1994

22-Mar-15 7:14

It's ok, I want to use KDF instead, but I don't get anything of that code..I solve it with sha1..

Richard Deeming23-Mar-15 3:31

How to add the current items into combobox at runtime

23-Mar-15 3:31

Hashing a password without using a unique salt for each record is a very bad idea.
Troy Hunt: Our password hashing has no clothes [^]
Salted Password Hashing - Doing it Right[^]

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

Member 1154531322-Mar-15 3:55

Member 11545313

22-Mar-15 3:55

in my forms i have combobox linked to sqlserver,the items in combobox is identity,two textbox and datetimepickers and button add ,when i press the button add at runtime i want to see the numbers of current adding information in combobox
please if you have any help answer me
think's a lot

Re: How to add the current items into combobox at runtime

Dave Kreskowiak22-Mar-15 4:42

Dave Kreskowiak

22-Mar-15 4:42

Member 11545313 wrote:
i have combobox linked to sqlserver

Uh, no you don't. You have a combobox bound to data that came from a database.

Member 11545313 wrote:
the items in combobox is identity,two textbox and datetimepickers and button add

Quite impressive that you crammed all of that into a combobox.

Prehaps you have a combobox bound to the identity column of your data? Then you also have two textboxes, two datetime pickers and a button labeled "Add"?

Member 11545313 wrote:
when i press the button add at runtime i want to see the numbers of current adding information in combobox

What do you mean by "numbers of current adding information"? That doesn't make sense at all.

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Re: How to add the current items into combobox at runtime

Mycroft Holmes22-Mar-15 14:13

Mycroft Holmes

22-Mar-15 14:13

I see your telepathy is only partially implemented!

Never underestimate the power of human stupidity
RAH

Re: How to add the current items into combobox at runtime

Dave Kreskowiak22-Mar-15 14:18

Dave Kreskowiak

22-Mar-15 14:18

It's only an experimental Alpha right now. I don't plan to release a Beta version until Spring of next year.

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data from file Word in DataGridView

Member 1071053221-Mar-15 5:10

21-Mar-15 5:10

Please tell me how to display a table of the Word document in DataGridView?

OriginalGriff21-Mar-15 5:22

21-Mar-15 5:22

What have you tried?
Where are you stuck?
What do you need to know?
Have you read the table from the word file?

Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...

Member 1071053221-Mar-15 6:24

21-Mar-15 6:24

In Word there is a table. I created a form WindowsForms and added elements DataGridVew and Button.

private Word.Application wordapp;
        private Word.Document worddocument;
        private Word.Range wordcellrange;

        private void button3_Click_1(object sender, EventArgs e)
        {
            wordapp = new Word.Application();
            wordapp.Visible = true;
            worddocument = wordapp.Documents.Open("C:\\Users\\Desktop\\Table.doc");
            Word.Table _table = worddocument.Tables[1];
            int a = _table.Rows.Count;
            int b = _table.Columns.Count;
            for (int i = 1; i <= a; i++)
                for (int j = 1; j <= b; j++)
                {
                    wordcellrange = _table.Cell(i, j).Range;
                    dataGridView3.Rows[i - 1].Cells[j - 1].Value = wordcellrange.Text;
                }
        }

Code only opens an existing file.

OriginalGriff21-Mar-15 6:32

21-Mar-15 6:32

And?
Have you looked at what happens with the debugger, so you have an idea what is going on? If not, do - you need to know what part of that is doing what you expect and what part isn't. And we can;t do that for you - we don't have access to your files!

When you have debugger results, let us know what is going on - if that doesn't let you directly what the problem is.

Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...

Member 1071053221-Mar-15 6:47

21-Mar-15 6:47

Index outside the range. It in a debugger.

OriginalGriff21-Mar-15 6:57

21-Mar-15 6:57

Good. So look at teh line that produces teh error - I don't know which it is, but the debugger will tell you.
I'd guess it's this one:

Word.Table _table = worddocument.Tables[1];

In which case, there are one or less tables in the document - remember that array indexes are zero based.
I'd check the return value to make sure that there is at least one table in there myself, and report / log a problem if there isn't.

Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...

Member 1071053221-Mar-15 7:24

21-Mar-15 7:24

error in this line

dataGridView3.Rows[i - 1].Cells[j - 1].Value = wordcellrange.Text;

OriginalGriff21-Mar-15 7:47