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You've got this all backwards. First you need to work out what problems you are trying to solve in your project, and then you can look at design patterns to see if someone has already done a partial solution to some or all of them.
The most common in my experience are simple ones like observer (though not really in C# as delegates and events do all the work for you) and boundary interfaces, which are so simple as to barely count as patterns at all. An MVP or MVVM variant is also very common.
Are those in the seminal 'Gang of Four' design patterns book? I don't know ... and that's the point, a pattern is not part of a gospel truth handed down by the gods of programming, it is advice and a worked example that you can modify to your needs. It doesn't matter if it comes from That Book, or a blog, or a website or a colleague's brain, if it fits the purpose.
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Hi, I have the following issue with my WinForms C# project and wonder if someone could point me to a solution...
I have a reference to a 3rd party DLL (which I am charged for and is licensed on a per end-user basis). The dll allows me to run certain functionality within my project. Ideally I'd like to to check if the Licence file \ DLL exists (I can do this) then if it exists, proceed as normal, but if it doesn't exists, then remove access to the functionality the Dll provides. The issue I have is that I have references in the project to the DLL, so if the licence file is not there or the DLL file is not present, the app explodes on startup. Is there any way I can get around this issue?
Many thanks.
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Good question. I found this article: Loading an Assembly[^]
If that doesn't solve the problem, you can dynamically load the assembly with the Assembly.Load[^] method, and then create objects from it with the Activator.CreateInstance[^] method.
This will allow you to remove the static reference from your project.
Also, see this article about early and late binding: Early and Late Binding[^]
EDIT: I apologize, that article is about VB. But if you search on "Late Binding C#" you'll find good information.
The difficult we do right away...
...the impossible takes slightly longer.
modified 3-Mar-14 15:03pm.
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Richard, many thanks for taking the time to reply. I'll check out the links you kindly posted.
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What I would do is have the functionality declared in an external assembly - the classes I wanted would implement interfaces stored in a DLL or the Exe and I would then use MEF to wire things together. This would allow you to use the interface as your type in the main program.
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MEF?
The difficult we do right away...
...the impossible takes slightly longer.
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You can actually catch the exception that gets thrown when a class can't be loaded. The trick is that the class must not be used in your Main method, because entering a method which uses a class the point that the class binder tries to load it, and you can't catch it.
So you can do something like
static void Main() {
try { EntryPoint(); }
catch(FileNotFoundException) {
}
}
static void EntryPoint() {
var x = new DependencyClass();
}
The 'correct' way to do it is to handle Application.AssemblyResolve but what I've described here can be useful if all you want to do is tell the user they need to install something which is missing in a more graceful way.
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Thanks BobJanova, this might be all I need.
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how to divided cell in Datagrid view. My code is don't work in fraction number. Someone advise me. Thanks you all.
foreach (DataGridViewRow row in this.dataGridView1.Rows)
{
int R1 = row.Index;
for (b = 0; b < dataGridView2.ColumnCount; b++)
{
a = 0;
for (c = 0; c < dataGridView2.RowCount; c++)
{
Ans_Grid.Rows[R1].Cells[b].Value =
(((Double.Parse(dataGridView1.Rows[R1].Cells[c].Value.ToString()))
* (Double.Parse(dataGridView2.Rows[c].Cells[b].Value.ToString())))).ToString()
;
Ans_Grid.Rows[R1].Cells[b].Value = a + Convert.ToInt16(Ans_Grid.Rows[R1].Cells[b].Value);
a = Convert.ToDouble(Ans_Grid.Rows[R1].Cells[b].Value);
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may be decimal will help you in getting your issue fixed
Mouli
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<pre>
using System;
using System.IO;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Boolean;
namespace Applica
{
class Program
{
static void Main(string[] args)
{
DirectoryInfo da = new DirectoryInfo("C:\\Folder9");
FileInfo[] Arr = da.GetFiles();
FileInfo ap = Arr[Arr.Length - 1];
long Totbyte = ap.Length;
string filePath = ap.FullName;
string temPath = Path.GetTempFileName();
byte[] data = File.ReadAllBytes(filePath);
File.WriteAllBytes(temPath, data);
byte[] dataB = new byte[1];
BitArray bits = new BitArray(dataB);
for (uint counter = 0; counter < Totbyte; counter++)
{
dataB[0] = data[counter];
for (uint count = 0; count < bits.Length; count++)
{
if (bits[count] == 0)
Console.Write(bits[count] ? "1" : "0");
}
}
}
}
}
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Totbyte is a long. Your loop is a uint.
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Even if I change that variable to a constant, the error still exist.
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My error is in the last 2 lines of the code:
bits[count]
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I changed it to an int and I still get an error.
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The same one or a new one?
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
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He did not insult you, he asked you a perfectly reasonable question. You have stated that you get an error, but you have given no details of what that error is. Is it "invalid argument", and if so on what line of code. If it is something different then show the details. But in either case please be clear what the problem is and where it occurs, and people will try to help you. But if you resort to insults and rudeness you are likely to get no help at all.
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Can you comment all your code?
Then I will fix it for you.
PS: always check variable is null or not, if you are not sure before calling it
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<pre>
using System;
using System.IO;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Boolean;
namespace Applica
{
class Program
{
static void Main(string[] args)
{
DirectoryInfo da = new DirectoryInfo("C:\\Folder9");
FileInfo[] Arr = da.GetFiles();
FileInfo ap = Arr[Arr.Length - 1];
long Totbyte = ap.Length;
string filePath = ap.FullName;
string temPath = Path.GetTempFileName();
byte[] data = File.ReadAllBytes(filePath);
File.WriteAllBytes(temPath, data);
byte[] dataB = new byte[1];
BitArray bits = new BitArray(dataB);
for (uint counter = 0; counter < Totbyte; counter++)
{
dataB[0] = data[counter];
for (uint count = 0; count < bits.Length; count++)
{
if (bits[count] == 0)
Console.Write(bits[count] ? "1" : "0");
}
}
}
}
}
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I don't understand what you are trying to do.
But if you want to write out the byte array of the file then here is the code
DirectoryInfo da = new DirectoryInfo("C:\\Folder9");
FileInfo[] Arr = da.GetFiles();
FileInfo ap = Arr[Arr.Length - 1];
long Totbyte = ap.Length;
string filePath = ap.FullName;
byte[] data = File.ReadAllBytes(filePath);
for (int counter = 0; counter < Totbyte; counter++)
{
Console.Write(data[counter]);
}
Remember that is byte array, not bit array
If you to write out bit array instead of byte array, replace
Console.Write(data[counter]);
Into
string yourByteString = Convert.ToString(data[counter], 2).PadLeft(8, '0');
Console.Write(yourByteString+" ");
modified 3-Mar-14 0:40am.
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There are two problems here: firstly that an array index needs to be an integer - and a uint needs an explicit cast to int - you can't use an implicit cast because it could "throw away" data in the form of positive values with the top bit set. Easiest solution: use int value in your for loop.
The second problem is that the BitArray indexer does not return an int value: it returns a bool. So if you correct the first error, the compiler will complain that it cannot compare an int with a bool!
Those are easily fixed to let your program compile:
for (int counter = 0; counter < Totbyte; counter++)
{
dataB[0] = data[counter];
for (int count = 0; count < bits.Length; count++)
{
if (!bits[count])
Console.Write(bits[count] ? "1" : "0");
}
} But... It's not going to work.
You don't change the value in Bits at all inside your outer loop - so each byte "value" is going to print as the same sequence of bits.
Personally, I wouldn't use a BitArray - it's an unnecessary complication here - just use the C# standard bit manipulation operators:
for (int counter = 0; counter < Totbyte; counter++)
{
int b = (int) data[counter];
for (int count = 0; count < 8; count++)
{
Console.Write(b & 1);
b = b >> 1;
}
}
Those who fail to learn history are doomed to repeat it. --- George Santayana (December 16, 1863 – September 26, 1952)
Those who fail to clear history are doomed to explain it. --- OriginalGriff (February 24, 1959 – ∞)
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I only need to evaluate if whether or not a "0" exist in the BitArray string. I dont care about the "1".
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