Re: After the Restoration of a DB with Stored Procedures are not recognised - C# Discussion Boards

Gareth H25-Mar-08 9:14

Gareth H

25-Mar-08 9:14

cocoonwls,

Not sure if thats possible, though have a look at Reflection.

http://msdn2.microsoft.com/en-us/library/ms173183(VS.80).aspx[^]

Regards,
Gareth.

Giorgi Dalakishvili25-Mar-08 9:28

Giorgi Dalakishvili

25-Mar-08 9:28

PostSharp[^] might help

Giorgi Dalakishvili

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my articles
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Not Active25-Mar-08 10:37

Not Active

25-Mar-08 10:37

Is policy injection what you're looking for?

http://msdn2.microsoft.com/en-us/library/bb410104.aspx[^]

only two letters away from being an asset

Pete O'Hanlon25-Mar-08 11:28

Pete O'Hanlon

25-Mar-08 11:28

You can do this. The technique that you are talking about is called a Rules Engine. There's a very good one available for .NET called NxBre.

Deja View - the feeling that you've seen this post before.

My blog | My articles

cocoonwls25-Mar-08 17:00

cocoonwls

25-Mar-08 17:00

Hi Pete O'Hanlon,

Is any example source/tutorial on NxBre. Please redirect me to the right way.

regards
lswang

Passing an array of struct

Pete O'Hanlon25-Mar-08 22:48

Pete O'Hanlon

25-Mar-08 22:48

Here[^] you go.

Deja View - the feeling that you've seen this post before.

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Jerry Graham25-Mar-08 7:48

25-Mar-08 7:48

Hi, i am trying to pass an array of struct in c# but I keep getting Inconsistent accessibility errors. I am including the code below:

________________________________________________________________________________________________________________
using System;
using System.Collections.Generic;
using System.Text;
using System.IO;

namespace friendstruct
{
class Program
{
class friendType
{

public string name;
public string age;
}

public static void load_data(friendType[]friends)
{
Console.WriteLine("Hello");
FileStream file = new FileStream("Marilia.txt", FileMode.Open, FileAccess.Read);
StreamReader reader = new StreamReader(file);
load_data();
for (int i = 0; i<3; i++)
{
name = reader.ReadLine();
str_age = reader.ReadLine();
age = Convert.ToInt16(str_age);
friends[i].name = name;
friends[i].age = str_age;
}
reader.Close();
}

public static void Main(string[] args)
{
int age;
string str_age;
string name;
friendType[] friends = new friendType[10];
load the data from the data file
load_data(friends);

//print the data file out
for (int i = 0; i < 3; i++)
Console.WriteLine("{0} {1} ", friends[i].name, friends[i].age);
}

}
}
_________________________________________________________________________________________________________________

Gareth H25-Mar-08 7:52

Gareth H

25-Mar-08 7:52

Jerry Graham,

If you change:

class friendType
{
 public string name;
 public string age;
}

To:

public class friendType
{
 public string name;
 public string age;
}

I think it should work. Basically, the error is because one class is set to public and the other isnt.

Regards,
Gareth.

Jerry Graham25-Mar-08 9:00

Re: Passing an array of struct [modified]

25-Mar-08 9:00

Hi,
That worked. thanks a lot. I have no syntax errors, however the problem crashes in the load_data() function when I attempt to insert a value into the array.

friends[i].name = name;

causes the following error:

Object reference not set to an instance of an object

Gareth H25-Mar-08 9:07

Gareth H

25-Mar-08 9:07

Jerry Graham,

In your code, you only create an array, you dont create any instances. So, you need to do:

friendType myFriend = new friendType();
myFriend.name = "bob";

friends[i] = myFriend;

On a side note, i'd personnly change your array to a generic list. eg:

List-friendType- friendArray = new List-friendType-;

(Change the "-" to "<" and ">", it wouldnt let me add them, guess CP doesnt allow for naughty HTML to be inserted)

This is because as you create the array, you set its size to be 10, now if you always populate that array with 10 friends, then its fine. But what if you want 11, your array doesn't handle that or if you only have 9 friends, then you have a null item. Just a tip.

Also, its a good idea to follow the standard naming convention.

http://msdn2.microsoft.com/en-us/library/ms229045.aspx[^]

Regards,
Gareth.

modified on Tuesday, March 25, 2008 3:17 PM

Jerry Graham25-Mar-08 9:36

25-Mar-08 9:36

I guess what is a bit puzzling to me is that this same code works if I use a single main function. it is only after I extract the reading of the data file into the load_data() function that these problems occur.

Jerry Graham25-Mar-08 10:58

25-Mar-08 10:58

Your suggestion worked. However could you tell me why this works?
--------------------------------------------------------------------------------------------------------------------using System;
using System.Collections.Generic;
using System.Text;
using System.IO;

namespace friendstruct
{
class Program
{
struct friendType
{

public string name;
public string age;
}

public static void Main(string[] args)
{
int age;
string str_age;
string name;
friendType[] friends = new friendType[10];
//load the data from the data file
FileStream file = new FileStream("Marilia.txt", FileMode.Open, FileAccess.Read);
StreamReader reader = new StreamReader(file);
for (int i = 0; i<3; i++)
{
name = reader.ReadLine();
str_age = reader.ReadLine();
age = Convert.ToInt16(str_age);
friends[i].name = name;
friends[i].age = str_age;
}
reader.Close();

//print the data file out
for (int i = 0; i < 3; i++)
Console.WriteLine("{0} {1} ", friends[i].name, friends[i].age);
}

}
}
-------------------------------------------------------------------------------------------------------------------

Guffa25-Mar-08 23:16

Guffa

25-Mar-08 23:16

When you create an array of structures, the array contains the instances of the structure.

When you create an array of objects, the array contains references to the objects. All references are null when you create the array, so you have to create the instances and assign the references to the array items.

Structures are tricky to use, especially if they are mutable, as your structure is. Unless you have a really good reason to use a structure, just keep to using classes.

Despite everything, the person most likely to be fooling you next is yourself.

Jerry Graham26-Mar-08 13:27

26-Mar-08 13:27

Thank you! I guess C# struct/class relationship is different from c++ class/struct.