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An alternative approach is to use a list of strings instead of a StringBuilder to build your list and then concatenate them as you need. Here's one way to do this:
public class FormattedStrings : List<string>()
{
public override string ToString()
{
StringBuilder sb = new StringBuilder();
bool started = false;
foreach (string item in this)
{
if (started)
{
sb.AppendFormat(",\"{0}\"", item);
}
else
{
started = true;
sb.AppendFormat("\"{0}\"", item);
}
}
return sb.ToString();
}
}I am assuming that you have assigned the @ symbol when you built your StringBuilder.
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Ew, yuck, duplicated code.  Needless boolean, needless if/else.
Stick the comma on the end and decrement it off when you're done.
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To be fair, this was just knocked up in the CP editor and doesn't reflect what I would push out the door.
I did look at doing it your way, but saw that you'd already posted that so it seemed that there wasn't much point to showing something that was already done - this is purely to stimulate the mind into thinking of other ways of solving the problem.
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I want to encrypt image by other image using Xor operation in c# as follow:
private byte[] EncypteXoRImage(byte[] inputImage, byte[] byImage)
{
byte[] Result = (byte[])inputImage.Clone();
if (byImage == null)
return Result;
for (int k = inputImage.Length / 3; k < inputImage.Length; k++)
{
Result.SetValue(Convert.ToByte((byte)Result.GetValue(k) ^ (byte)byImage.GetValue(k % byImage.Length)), k);
}
return Result;
}
where inputImage is picture which i want to encrypt,the problem is when i want to display encrypted picture on the picturebox,the result is:
the encrypted part was displayed by a gray background
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Code doesn't seem to make sense. Could you try this?
private byte[] EncypteXoRImage(byte[] inputImage, byte[] byImage)
{
if (byImage == null)
return (byte[])inputImage.Clone();
byte[] result = new byte[inputImage.Length];
for (int k = 0; k < result.Length; k++)
{
result[k] = (byte)(inputImage[k] ^ byImage[k]);
}
return result;
}
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You can make your method a lot easier to understand by using actual array references instead of GetValue and SetValue - and also by throwing awy unnecessary conversions:
private byte[] EncypteXoRImage(byte[] inputImage, byte[] byImage)
{
byte[] Result = (byte[])inputImage.Clone();
if (byImage == null)
return Result;
for (int k = inputImage.Length / 3; k < inputImage.Length; k++)
{
Result[k] ^= byImage[k % byImage.Length];
}
return Result;
}
However, it will have no affect on your problem - since the code is equivalent.
Out of interest, I tried this with two of my pictures:
private void myButton_Click(object sender, EventArgs e)
{
Image i = Image.FromFile(@"D:\Temp\MyPic.jpg");
Image j = Image.FromFile(@"D:\Temp\MyOtherPic.jpg");
pictureBox1.Image = i;
pictureBox2.Image = j;
MemoryStream msI = new MemoryStream();
i.Save(msI, System.Drawing.Imaging.ImageFormat.Bmp);
MemoryStream msJ = new MemoryStream();
j.Save(msJ, System.Drawing.Imaging.ImageFormat.Bmp);
byte[] res = EncypteXoRImage(msI.ToArray(), msJ.ToArray());
MemoryStream msK = new MemoryStream(res);
Image k = Image.FromStream(msK);
pictureBox3.Image = k;
}
private byte[] EncypteXoRImage(byte[] inputImage, byte[] byImage)
{
byte[] Result = (byte[])inputImage.Clone();
if (byImage == null)
return Result;
for (int k = inputImage.Length / 3; k < inputImage.Length; k++)
{
Result[k] ^= byImage[k % byImage.Length];
}
return Result;
}
Apart from being a pretty useless encryption technique (I could work out what both pictures were from the composite, pretty much, in the same way that I can read Captcha codes), it worked - I did not get a solid grey background with either version of your method.
So I assume it is your conversion from Image to byte array that is at fault.
Ideological Purity is no substitute for being able to stick your thumb down a pipe to stop the water
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Hi,
I have this error in my code that am having difficulties in rectifying it. Initially, my code looked like this..
private void CalculateTheMortgage()
{
double loanAmount = (double)txtLoanAmount.CurrentValue;
double taxesPerYear = (double)txtPropertyTax.CurrentValue;
double downPayment = (double)txtDownPayment.CurrentValue;
double interestRate = (double)udInterest.Value / 100;
double termOfLoan = (double)(udTerm.Value * 12);
double propertyTax = (double)txtPropertyTax.CurrentValue;
double insurance = (double)txtInsurance.CurrentValue;
double payment = (loanAmount - downPayment) * (Math.Pow((1 + interestRate/12), termOfLoan) * interestRate)/(12 * (Math.Pow((1+interestRate/12), termOfLoan) - 1));
payment = payment + (propertyTax + insurance) / 12;
txtPayment.CurrentValue = (int)payment;
}
and i changed it a little to this...
private void CalculateTheMortgage()
{
double loanAmount = Convert.ToDouble(txtLoanAmount.Text);
double taxesPerYear = Convert.ToDouble(txtPropertyTax.Text);
double downPayment = Convert.ToDouble(txtDownPayment.Text);
double interestRate = (double)udInterest.Value / 100;
double termOfLoan = (double)(udTerm.Value * 12);
double propertyTax = Convert.ToDouble(txtPropertyTax.Text);
double insurance = Convert.ToDouble(txtInsurance.Text);
double payment = (loanAmount - downPayment) * (Math.Pow((1 + interestRate / 12), termOfLoan) * interestRate) / (12 * (Math.Pow((1 + interestRate / 12), termOfLoan) - 1));
payment = payment + (propertyTax + insurance) / 12;
txtPayment.CurrentValue = (int)payment;
}
which removed the error message below. Now i wanna change this
txtPayment.CurrentValue = (int)payment; piece of code so that the same error cannot occur again. There is a blue line under 'CurrentValue'
This is the error am getting...
'System.Windows.Forms.TextBox' does not contain a definition for 'CurrentValue' and no extension method 'CurrentValue' accepting a first argument of type 'System.Windows.Forms.TextBox' could be found (are you missing a using directive or an assembly reference?)
Please help me here
Thanks
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textbox.Text ?
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When i write it like this
txtPayment.Text = (int)payment; am getting this error
Cannot implicitly convert type 'int' to 'string' with a blue line under '(int)'
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Don't convert it to int when trying to put it into a textbox.
There are only 10 types of people in the world, those who understand binary and those who don't.
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txtPayment.Text = payment.ToString();
or:
txtPayment.Text = payment.ToString("0.00 $");
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Can't believe it was that simple....
Thanks a lot!
It worked..
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There are many things wrong here.
Convert.ToDouble will work and is preferable of
(double)somevalue but the best method is
double.TryParse or int.TryParse
Secondly you need to use
txtPayment.Text = payment.ToString(); and make sure payment is not null.
If you do want an integer, you need to indeed first cast the double to an integer and then that integer to a string (or use round and floor functions)
Why do you cast to double in these cases?
double interestRate = (double)udInterest.Value / 100;
double termOfLoan = (double)(udTerm.Value * 12);
What is this code for? Own project, a book, homework?
V.
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Very minor, but...
V. wrote: make sure payment is not null
payment is a double (not double?) so cannot be null 
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You're absolutely right.
V.
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V. wrote: and is preferable
No it isn't.
V. wrote: the best method is
Not when a cast will do.
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double.Parse is not equivalent to a double cast. One does a string-to-number conversion, the other does a number-to-number conversion. You can use Convert.ToDouble to do either, but I disagree that it's preferable for either scenario: use the mechanism that makes sense in context. A cast translates to a single IL opcode, not a whole method call, after all.
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Hello!
It's been only a few weeks since I have started to learn WPF, and I came across some assignments that needed color changing in the images being generated. For this, I was able to use radio buttons and get away with it, but I am interested to find out about using colour pickers.
Any idea as to how? Please share with me. I would appreciate it if the app is really simple though, because I am just an enthusiastic beginner.
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You mean something like this[^] one?
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Yes, something like that, but much simpler, so that a beginner can grasp the idea behind it.....
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I don't think you're going to get anything WPF based that's much simpler than that.
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I have to agree with Pete on this one.
"I have a theory that the truth is never told during the nine-to-five hours. "
— Hunter S. Thompson
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Look at the mouse move event on the colour picker control, that's where the 'magic' happens.
And ew, Sasha uses empty catch blocks? heh.
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Hi,
I am using this to refer to the MdiParent:
BrowsePatientForm.MdiParent = this;
is it possible to to refer to specific form instead so it will be something like this:
BrowsePatientForm.MdiParent = frmMain;
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jrahma wrote: is it possible to to refer to specific form instead
Yes it is.
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