C# datagridview two column multiple each other

Question

Hi I have one problem when I am trying to multiply two column's value with each other.Here is how it looks like: -----Value-------Amplifier -----30222-----0.002 ------22222-----0.004 ------0-----------0.01 what I want is Column of Value multiply Amplifer and store the result in Value column. Here is my code: for ( int n = 0; n { double i= Convert .ToDouble(dataGridView1.Rows[n].Cells[Value].Value.ToString()); double j= Convert .ToDouble(dataGridView1.Rows[n].Cells[ Amplifier ].Value.ToString()); dataGridView1.Rows[n].Cells[Value].Value= Convert .ToString(i*j); } But I get one error in Here: double j= Convert .ToDouble(dataGridView1.Rows[n].Cells[ Amplifier ].Value.ToString()); which said : Input string was not in a correct format. can anyone help me out with this...Thanks a lot

Vulpes · Answer

OK in your original code try the highlighted changes: for (int n = 0; n { double i=Convert.ToDouble(dataGridView1.Rows[n].Cells[Value].Value.ToString() .Replace('.' '') ); double j=Convert.ToDouble(dataGridView1.Rows[n].Cells[Amplifier].Value.ToString() .Replace('.' '') ); dataGridView1.Rows[n].Cells[Value].Value=Convert.ToString(i*j); }

Emma Emma · Answer

Thanks Vulpes I get it work by just dividing the Amplifier column...it works fine now Thanks a lot for helping out! BR Emma

Vulpes · Answer

The problem there is that you're permanently altering the values in the 'Value' column of the DGV following the multiplication. It would be better to introduce a new column to hold the product (or whatever) of the two values so your original values would be maintained and you could then do other calculations on them.

Emma Emma · Answer

Hi Vulpes Thank you very much. it works now by replacing . with  Maybe I want to ask I put this function under a checkbox. Now every time the checkbox is checked they multiply. then uncheck the value is still the same with after multiply...then if checked again they multiply again....it is like rotating never goes back to normal value even I uncheck the checkbox... you know how to manage this thanks a lot!

Emma Emma · Answer

Yessss Vulpes... You are right! I tried to change the first 0.01 to 10 it works then I change from xnl file from 0.01 to 001 then it works in datagridview. In datagridview they look like the same... so now I need to figure out how to change all the . in XML file into  so that datagridview can understand it... Thankssss so muchhh !

Vulpes · Answer

Is is possible that this code is running under a culture where the decimal separator is not a dot but a comma (such as French) or some other character? The only other (remote) possibility is that what appears to be a dot is in fact some other unicode character which looks like one.

Emma Emma · Answer

I get the messagebox with: 5 and 4 is invalid.... I checked many times. There is no problem with the numbers. The error happened when n=0 so this even does not matter with the other rows except row 0. That is why I am thinking maybe it is the format of the value...

Vulpes · Answer

The only thing I can think of is that you've somehow (from the XML file or otherwise) got some non-printing character such as '\0' in the middle of one of those numbers. To test this theory try replacing this line : string message = String.Format({0} and {1} is invalid s1.Length s2.Length); If you don't get 5 and 4 is invalid then this theory must be correct.

Emma Emma · Answer

Hi do you think it has something to do with my data format? The data is loaded from one xml file.

Emma Emma · Answer

Yes Durga I get the first row's original value. with string s1 = dataGridView1.Rows[n].Cells[Value].Value.ToString(); string s2 = dataGridView1.Rows[n].Cells[Amplifier].Value.ToString(); I get 20333 and 0.01 ...

Emma Emma · Answer

Thanks Vulpes after trying your code it gives the error messagebox said: 20333 and 0.01 is invalid

Durga Prasad · Answer

I think you are getting some string value with dataGridView1.Rows[n].Cells[Amplifier].Value.ToString() value. Try to find out with debug the code.

Vulpes · Answer

In an attempt to get to the bottom of this try changing your code to this: int n = 0; try { for (n = 0; n { double i=Convert.ToDouble(dataGridView1.Rows[n].Cells[Value].Value.ToString()); double j=Convert.ToDouble(dataGridView1.Rows[n].Cells[Amplifier].Value.ToString()); dataGridView1.Rows[n].Cells[Value].Value=Convert.ToString(i*j); } } catch(FormatException) { string s1 = dataGridView1.Rows[n].Cells[Value].Value.ToString(); string s2 = dataGridView1.Rows[n].Cells[Amplifier].Value.ToString(); string message = String.Format({0} and {1} is invalid s1 s2); MessageBox.Show(message); }

Emma Emma · Answer

Hi Vulpes it is my typing mistake...all the value I get is from one xml file. They are all correct numbers.... So strange it does not work with multiply

Vulpes · Answer

Unless it's a typo this value (your 2nd post above): 1 0 is illegal because it includes a space between the 1 and 0.

Emma Emma · Answer

Thanks Durga it does not work. The correct value for i is: 20333 the j is 0.01. After the error occurs it becomes: i is 20333.0 and j is 0.0... then error happens...does this means anything

Durga Prasad · Answer

Use Trim() method after ToString() I hope this will work otherwise check what value are you getting for dataGridView1.Rows[n].Cells[Amplifier].Value

Emma Emma · Answer

Thanks Santhosh I checked all the value are correct. they are like 0.001 10 1 0 or 0.002 ...no illegal characters.... do you think it is related to double...is there any type I can use for 0.001 which has 2 decimal point behind... Thanks

Santhosh Kumar Jayaraman · Answer

it looks one of the value in Amplifier column has some alphabets or something else.Thats why its giving error. Please check all the values in amplifier column