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Hi all,
I'm not sure this is the right forum,but I thought I'll give it a try,since not getting answers from DevExpress support center.
I'm using DevExpress GridView for winforms applications.
Also using VS2010 and Linq to SQL.
My grid view is binded to a LINQ table which represent a table in my database.
Let say I have a Person class with two properties - FirstName and LastName.
These two properties are persistent.
What I'm trying to do is to add a third property which will not be persistent and called FullName = LastName + FirstName.
This is working fine and the grid display the full name correctly.
My problem is when trying to filter values using the filter buttons in the column header,the dropdown list is empty...
When making FullName saved in the database - everything is OK.
Can anyone save me?
Thanks,
Eli
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Can you override some kind of grid_OnFilter event?
There would be just added filter for both FirstName and LastName. But really whole idea for that grid is wrong. Why? What happend whe you will have 1000, 10000, or 1000000 records? Grid will fetch all of them filter, sort and then show. More records then more time this will take.
No more Mister Nice Guy... >: |
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using (FileStream fs = File.OpenRead(path))
{
fs.BeginRead();
}
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A few points;
- "Help" is a too generic subject; they're all looking for help
- The question is hard to find; ask a question, explain what you tried, and why it didn't work
- Reading a
Stream is often-described pattern[^]. Do you really need the async version? Wouldn't ReadToEnd[^] be a bit simpeler?
Did you write/use an async method before?
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Sorry your question is not very clear.
BeginRead()[^] does not have any overloads that accept parameters.
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Here is my code:
private void loadDataToolStripMenuItem_Click(object sender, EventArgs e)
{
TabPage tp = new TabPage();
tp.Text = "Data";
System.Windows.Forms.CheckedListBox AvailableDataList = new system.Windows.Forms.CheckedListBox();
AvailableDataList.Dock=DockStyle.Fill;
tp.Controls.Add(AvailableDataList);
for (bb = 0; bb < 8; bb++)
{
AvailableDataList.Items.Add("Bob");
switch(SelectName(bb))
{
case false:
AvailableDataList.SetItemChecked(bb, false);
break;
case true:
AvailableDataList.SetItemChecked(bb, true);
}
tabControl1.TabPages.Add(tp);
}
private void button4_Click(object sender, EventArgs e)
{
label1.text = AvailableDataList.Items.Count;
}
The code under the loadDataToolStripMenuItem works just fine.
I’m creating a CheckedListBox, populating it, then creating (adding) a TabPage, and placing the CheckedListBox on the new tab.
Problem is the created CheckedListBox AvailableDataList is not accessible in the button4_Click routine.
I don’t know how to make it public throughout the form.
Can someone help?
Thanks!
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At the moment it is a method level variable, you need to make it a class level one:
System.Windows.Forms.CheckedListBox AvailableDataList;
private void loadDataToolStripMenuItem_Click(object sender, EventArgs e)
{
TabPage tp = new TabPage();
tp.Text = "Data";
AvailableDataList = new system.Windows.Forms.CheckedListBox();
AvailableDataList.Dock=DockStyle.Fill;
tp.Controls.Add(AvailableDataList);
for (bb = 0; bb < 8; bb++)
{
AvailableDataList.Items.Add("Bob");
switch(SelectName(bb))
{
case false:
AvailableDataList.SetItemChecked(bb, false);
break;
case true:
AvailableDataList.SetItemChecked(bb, true);
}
tabControl1.TabPages.Add(tp);
}
private void button4_Click(object sender, EventArgs e)
{
if(AvailableDataList != null)
label1.text = AvailableDataList.Items.Count;
}
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How do you programatically open a file in c# to append?
I tried searching online for an example and so far I have not found anything.
There is System.IO.StreamWriter and there is System.IO.StreamReader but there is no StreamAppend. Is there some way to use StreamWriter without overwritting the content of the existing file? Is there some way to use System.IO.Stream with some sort of appending criteria?
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You can use a FileStream with FileMode.Append
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Xarzu wrote: How do you programatically open a file in c# to append?
As explained in the tutorials you can Google.
Xarzu wrote: I tried searching online for an example and so far I have not found anything.
"C# append text example". Nothing?
Xarzu wrote: System.IO.StreamWriter and there is System.IO.StreamReader
You don't need a stream; File.AppendAllText[^] does as requested. Usage is simple;
File.AppendAllText(@"C:\Temp\Test.txt", "Text to append");
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Hi, New here, and would be very thankful for any help someone can give me.
The code I am working for is a population estimator. It has 3 text boxes, the first is two enter the starting population, the second is to enter the daily increase in that population in a percentage, and the third is the number of days to multiply that by.
My first issue is with the second text box. I don't know how to enter the data as a percent. As of now it is only entering as a whole number, so I when I right in text box one the number 2, in box2 the number 30, and in three the number 10, I get the 302. Not 21.209 like it should be.
Secondly, it all displays in a listbox, and its supposed to loop for every day you enter. I've got the loop to loop by days, but it just runs the same calculation, I want it make every entry build off the last.
Example:
It should say
2
2.6
3.38
4.394
5.7122
etc
I've entered in the code below.
Thanks for any help!
private void calculateButton_Click(object sender, EventArgs e)
{
int organisms;
int days;
int growth;
int population;
int count = 1;
if (int.TryParse(OrganismsTextbox.Text, out organisms))
{
if (int.TryParse(DailyTextbox.Text, out growth ))
{
if (int.TryParse(DaysTextbox.Text, out days))
do
{
population = organisms + growth * days;
resultsListbox.Items.Add("The population For day " + count + " is " + population.ToString("n1"));
count = count + 1;
}
while (count <= days);
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You probably need to use double values rather than integers for your calculations, for greater accuracy. You also need to convert the number taken from the second textbox to a percentage; it's not 30 it is .30. You also need to change your calculation to calculate the growth in compound terms - I'm not sure of the actual formula.
One of these days I'm going to think of a really clever signature.
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There are a couple of simple things to do - firstly as Richard said, you need to use floating point values instead of integers:
2 + 30% is 2.6, but as an integer it is 2 again! 
The second is that you are looping through the days, so you don't need to include the number of days in each calculation - just use the result from the previous day.
The third is that when you want an increased value, you can't just multiply by the percentage - 2 * 30% is 0.6, so your increase is 0.6, not your population. To increase your population, multiply but 1.0 + the percentage.
Finally, there is a better way to loop through the days: use a for loop instead of a while:
for (int day = 1; day <= days; day++)
{
... calculate here
}
So, my version would be:
resultsListbox.Items.Add(string.Format("The population for day {0} is {1}", day, organisms));
organisms *= 1.0 + percent;
with percent adjusted to 0.3 as Richard suggested.
If you get an email telling you that you can catch Swine Flu from tinned pork then just delete it. It's Spam.
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Thanks guys! Got it to work!
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Glad to hear it!
If you get an email telling you that you can catch Swine Flu from tinned pork then just delete it. It's Spam.
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I'm having trouble with the interface for the Factory Design Pattern. I've looked at
http://dotnet.dzone.com/articles/design-patterns-c-factory,
which follows my design very closely since it was the first good example I found a while back.
I took a look at
http://stackoverflow.com/questions/27294/abstract-factory-design-pattern,
but my design is very different.
Right now, this is what it looks like. I have included a lot of code because I have a feeling the problem has to do with the visual studio project breakdown. It used to be more simple, with my CR5, interface, factory, CB_spec, El, etc in the same visual studio project. I had to move things around as shown per design discussions and the need for CR6, etc to be separate. Now I'm getting some compilation problems I'm not sure what to do with. See ** below for the first and worst. My question is regarding the compilation issue below.
My iCR Visual Studio project which is the interface:
public interface iCR
{
int CB_IO_Init(int slaveIndex);
int WritePortReady();
int WritePortBusy();
void initCRData(byte[] writeBuffer, byte[] statusBuffer, int SlaveIndex, USB_Comm.CB cb, int cr_Type);
int ProcessTWriting(ref Byte[] writeDat, ref Byte[] statusDat, ref Byte[] dataDumpWriteCheck);
void Failure(String message);
void Success(String message);
}
My CR_Factory Visual Studio project
namespace CR_Factory
{
public class Cr
{
}
public class CRFactory
{
public enum CRType
{
CR0,
CR1,
CR3,
CR4,
CR5,
CR6
}
public CRFactory()
{
}
public iCR GetCR(CRType type)
{
iCR cr = null;
switch (type)
{
case CRType.CR5:
cr = new CR5();
break;
case CRType.CR6:
break;
default:
throw new ArgumentException(string.Format("A CR of type {0} cannot be found", Enum.GetName(typeof(CRType), type)));
}
return cr;
}
public CRType DetermineCR_Type(int type)
{
switch (type)
{
case 0:
return CRType.CR0;
case 1:
return CRType.CR1;
case 3:
return CRType.CR3;
case 4:
return CRType.CR4;
case 5:
return CRType.CR5;
case 6:
return CRType.CR6;
default:
throw new ArgumentException(string.Format("A type of type {0} cannot be found", type));
}
}
}
}
My CR5 Visual Studio Project has a lot of classes in it, but right now I’m just showing you the part referred to in the factory. Later I’ll create a CR6 VS project, etc. As you can see, the compiler doesn't think I implemented initCRData but it's right there, and curly brackets are fine.
public class CR5 : iCR **compile error CR5_new.CR5 does not implement interface member iCR.initCRData(byte[],byte[],int,USB_Comm.CB,int)
{
CB_703 cb_specific = null;
public CR5()
{
cb_specific = new CB_703(SlaveIndex);
}
public void initCRData(byte[] writeBuffer, byte[] statusBuffer, int slaveIndex, USB_Comm.CB cb_specificInstance, int crType)
{...
}
public int CB_IO_Init(int SlaveIndex)
{
int result = -534;
result = cb_specific.IO_Init(SlaveIndex);
return result;
}
.
.
.
}
I have another Visual Studio Project (actually several) that instantiates the factory and gets the appropriate type. We’ll call it El:
namespace CrWr
{
public partial class PControl : UserControl
{
public PControl()
{
}
public Control GetPControl(USB_Comm.CB cbInstance, string dllSelected, THandlerApplication.Temp.TEMP[] temp, string dll, SC.SC.S_C c0)
{
cb = cbInstance;
createControls();
itsDll = dll;
tArr = temp;
cert = c0;
CR_Factory.CRFactory factory = new CR_Factory.CRFactory();
CRFactory.CRType type = factory.DetermineCR_Type(cr_Type);
try
{
cr = factory.GetCR(type); }
catch (Exception ex)
{
Console.WriteLine(ex.InnerException);
}
return this;
}
private void OnP()
{
int result = -536;
while (rL)
{
result = cr.CB_IO_Init(SlaveIndex);
if (result == 0)
{
…
}
}
.
.
.
}
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Try this;
public class CR5 : iCR
{
CB_703 cb_specific = null;
public CR5()
{
cb_specific = new CB_703(SlaveIndex);
}
public void iCR.initCRData(byte[] writeBuffer, byte[] statusBuffer, int slaveIndex, USB_Comm.CB cb_specificInstance, int crType)
{...
}
public int CB_IO_Init(int SlaveIndex)
{
int result = -534;
result = cb_specific.IO_Init(SlaveIndex);
return result;
}
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When I do that, the compilation error turns to:
The modifier 'public' is not valid for this item.
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Makes sense. Being an interface, marking it public would be redundant. Delete the keyword.
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Thanks for the comment. I got rid of "public" so now it's
void iCR.initCRData(byte[] wrBuff, byte[] stBuffer, int slaveIndex, USB_Comm.CB cb_spec, int crType)
{}
However, I'm getting compilation errors indicating it's not being seen:
CR5_new.CR5 does not implement interface member iCR.initCRData(byte[], byte[], int, USB_Comm.CB, int)
iCR.initCRData in explicit interface declaration is not a member of interface
Any thoughts? On the one had it doesn't seem to see that it's there, but then it sees it and thinks it's not a part of the interface. This is what the interface VS project looks like,
public interface iCR
{
. . .
void initCRData(byte[] wrBuffer, byte[] stBuffer, int SlaveIndex, USB_Comm.ClearBox cb, int cr_Type);
. . .
}
My iCR dll is referenced in my CR5_new VS project. It could be something really basic, since I've only programmed with VS/C# for a little over 6 months...I have more C++ experience. Thanks for all of your help. I really appreciate it.
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MichCl wrote: My iCR dll is referenced in my CR5_new VS project.
It's easier to "test" it in a separate console-app; create the desired structure there, isolated from the rest of your app.
Does it work if the interface and consuming class are in the same project? If yes, there's a problem with the reference (check namespaces, using-clauses etc) If no, there's a problem with the syntax.
This case, I'm guessing syntax. Compare your code to the example from MSDN[^].
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It does work if the iCR, Factory class, Cr5, and El are in the same VS project, with the USB_Comm.CR class in a separate VS project.
It's weird...when I refer to the method in my CR5 project (the one we've been discussing), VS fills in the method I'm referring to, but when I try to get it to suggest the parameters I'm supposed to supply, it's not coming up with anything.
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MichCl wrote: It does work if the iCR, Factory class, Cr5, and El are in the same VS project, with the USB_Comm.CR class in a separate VS project.
A syntax-error would have generated a compile-error. The fact that it works implies that the code is correct, and that it's a problem with the references.
Did you reference the project (add the project-source to the solution) or the assembly? Is there an old version of this assembly in the GAC?
Alternatively; what happens if you rename the interface? Does the exception pick up the correct new interface-name?
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I figured it out... See below, after my response to your last post.
There are compilation errors with the VS project distributed as I first presented it. It's
CR5_new.CR5 does not implement interface member iCR.initCRData(...) (but it does)
and
iCR.initCRData in explicit interface declaration is not a member of interface (but it is)
I have a reference to the VS project iCR in my CR5_new project.
I'm not sure what you're referring to with GAC above. When I look in my CR5_new project, even though I see it referenced in the solution explorer under references, when I look in MyComputer, I don't see a copy of the dll, so presumably it's not a copy, it's actually looking for it in the original location. When I look at the Solution Explorer properties of iCR, it's giving the path to the correct original location for the dll.
Alternatively, when I change the name of the interface to iC from iCR, I had to change it in
public class CR5:iC in my CR5_new namespace/visual studio project. Plus I had to change it to iC.initCRData(...). Then the above compile errors changed to use the new interface name.
I figured it out when I was looking into the above... My CR5 project had another class in it for USB_Comm.CB. The iCR was also referring to this class for parameters in the interface. So they were cross-referencing. So I moved the USB_Comm.CB class into it's own VS project so they can both refer to it without cross-references.
On the one hand I feel like I'm not using multiple class VS projects, but if I kept these things in them, I'd have repeats of classes in my VS projects like El. Plus when I create my CR6 project, I can re-use code more. Thanks for all of your help!! 
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MichCl wrote: I figured it out... See below, after my response to your last post.
Whehe, cool - and good explanation!
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