When creating webform in VS 2013, the codebehind contains several using alias but when I save the page all the using alias are removed. Only one using using System; is kept. Why is it so?
Also the code behind has namespace, when I see different web pages tutorials they simply start with public partial class. What is the difference ? Should I simply remove the namespace, does it effect my webpages ?
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace Sample.UI.pages
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
}
}
1) If you aren't adding any extra code that would be accessible via a using statement, then you don't need any extra using statements.
2) public partial class refers to the fact that the class is split over 3 files. One is the aspx file, the designer.cs file, and the aspx.cs code behind. Do not remove any namespaces unless you know what you're doing. The CLR uses the assemblies namespaces to find code to execute.
Related
Very basic knowledge on c# and is the first i use anything p/invoke related.
Help me pls, i have made this code but it doesnt seem to work.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Runtime.InteropServices;
namespace WindowsFormsApplication3
{
public partial class Form1 : Form
{
[DllImport("C:\\Users\\lchris\\Desktop\\SevenZipLib_9.13.2\\SevenZipLib\\SevenZipLib\\7z86.dll")]
public static extern void SevenZipArchive(string c);
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
using (SevenZipArchive archive = new SevenZipArchive("file.rar"))
{
foreach (ArchiveEntry entry in archive)
{
Console.WriteLine(entry.FileName);
}
}
}
}
}
It tells me that SevenZipArchive is a 'Method' and is being used like a 'type'.
I have include the library to my project already, i just dont know how to use it.
Here is the library:
https://sevenziplib.codeplex.com/
You first need to remove this code:
[DllImport("...")]
public static extern void SevenZipArchive(string c);
You do not need to provide any p/invoke declarations. The library wraps that up for you.
This is a .net assembly. You use it just as you use any other. Take the following steps:
Download the project. You already did that I think.
Build the solution. Make sure that
In your project, add a reference to the assembly that you built in the previous stage. It's SevenZipLib\bin\Debug\SevenZipLib.dll or SevenZipLib\bin\Release\SevenZipLib.dll depending on the target you selected.
Add using SevenZipLib; to your project code to to gain access to the namespace.
Once you've done that your code will work. You can use the tests project that is supplied as part of the download as a rich source of example code.
Im trying to use LINQ in my ASP.NET/C# website. For that I need to access the class 'modelDataContext' which is a part of the LINQ namespace.
Im using Visual Studio 2010 Professional
This is my C# code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Data.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class admin_new_feed : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
modelDataContext data = new modelDataContext();
}
}
Full error message I get
Error 1 The type or namespace name 'modelDataContext' could not be
found (are you missing a using directive or an assembly
reference?)
Things i've tried, which doesn't solve problem
Adding the reference (Right-click solution, add reference - System.Data.Linq)
Re-create the website
Right clicking on the line, to see if the tab "Resolve" was there. But it wasn't.
I was working through the MSDN tutorial for Crystal Reports, and I get to the Binding the Embedded Report to the CrystalReportViewer Control step:
When I try the build, it tells me that I am missing my using declaration for Hierarchical_Grouping class. This brings up two questions for me...
What is the namespace for this class definition?
Is there an easy way of determining the namespace of a given class?
In another answer I saw the 'ALT, SHIFT, F10' and the 'CTRL, [period]' suggestions for intellisense, but they don't work in my Visual Studio.
I'm sure I have done something ridiculously stupid....sorry in advance....
Here's the code for the form:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using CrystalDecisions.CrystalReports.Engine;
using CrystalDecisions.Shared;
namespace CrystalTest3
{
public partial class Form1 : Form
{
private Hierarchical_Grouping hierarchicalGroupingReport;
public Form1()
{
InitializeComponent();
}
private void ConfigureCrystalReports()
{
hierarchicalGroupingReport = new Hierarchical_Grouping();
crystalReportViewer.ReportSource = hierarchicalGroupingReport;
}
private void Form1_Load(object sender, EventArgs e)
{
ConfigureCrystalReports();
}
}
}
I am assuming that you are referring to this tutorial.
The Hierarchical_Grouping seems to refer to the report file - which will contain the class named Hierarchical_Grouping. Have you added the report to your project?
The report should be somewhere in these Sample Reports Directories.
I made the same ASP.NET C# project in both VS2010 and MonoDevelop using these two classes among the standard files (Site.Master, Web.Config, Default.aspx, etc.) and recieve this same error (CS0234) seen at the bottom.
Login.cs:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using mynamespace;
namespace mynamespace
{
public partial class Logon
{
public void btnClicked(object sender, EventArgs e)
{
//ERROR IS HERE:
mynamespace.Test session = new mynamespace.Test();
//Obviously, this doesn't work either:
Response.Write(session.echoUser());
}
}
}
Test.cs:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using mynamespace;
namespace mynamespace
{
public class Test
{
public string echoUser()
{
return "foobar";
}
}
}
I recieve the same error in both IDEs, here is the MonoDevelop error:
The type or namespace 'Test' does not exist in the namespace 'mynamespace' (are you missing an assembly reference?) (CS0234) Logon.cs
Basically, the class Test refuses to instantiate. Any input is appreciated!
If you have that Test class in an ASP.Net web project, then you need to place it in the App_Code folder, not just anywhere in the site.
You need to refer the projects to each other, if you haven't done so yet. I'm guessing that you don't get the intellisense to show the class in the other namespace, right?
You can see the References on the right side (most cases) under your project view. You can right click there and choose to Add reference. Then you browse to the binaries from the pther projects. (You might be able to point to the project itself too - I don't have VS in front of me at the moment.)
Also, It's a convention to use camel case for namespaces, so it should be MyNameSpace.
If the classes are in the same project, you might want to skip using mynamespace and refer to the class by Test intead of mynamespace.Test.
If these are both in the same project, please check that both files are included in the project and have the "Build Action" property set to "Compile". Please also check that all of these namespaces have exactly matching spelling and casing.
I have written a simple Form1 (inherit from Form) class in Visual Studio C#. All was good.
Then I wanted to change the name of the class and the namespace to something meaningful instead of the default 'WindowApplicationForm1' . I also changed the file name of the Form1.cs class to match the new class name (IRISReaderGUI and Com.Harmonysoft). First I manually rename the code, then compiled, the compiler gave me lot of error that I could not figure out. So I tried to rename my class and namespace using 'refactoring' menu. My code still didn't compile.
I did some research and change the 'IRISReaderGUI.Designer.cs' class name and namespace to match the new names. C# still didn't give me no joy.
The compiler erros message was :
'Com.Harmonysoft.IRISReaderGUI.Dispose(bool)': no suitable method
found to override'
On the designer view it said : The base class'System.object' can not be designed.
So I guess my IRISReaderGUI did not correctly inherit the System.Windows.Forms.Form class, this was confirmed by putting the mouse over the Form word in the code, Visual Net does not popup the text describing the class, and pressing F12 does not get me to the Form definition.
Here is the code :
"IRISReaderGUI.Designer.cs"
namespace Com.Harmonysoft
{
partial class IRISReaderGUI
{
.......
}
"IRISReaderGUI.cs"
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Linq;
using System.Text;
using System.Data.Odbc;
using System.Data.OleDb;
using System.Data.OracleClient;
using Com.StellmanGreene.CSVReader;
using System.Windows.Forms;
using System.IO;
namespace Com.Harmonysoft
{
public partial class IRISReaderGUI : Form
{
......
}
I am new to C# and Visual Studio, I have previously worked with Java compiler and Vim editor mostly. Could anyone please help me to compile my code ?
Forms in VS2005 and up are partial classes. You edited the one part but not the other. In the Solution Explorer window, expand the node next to the form and double-click the Designer.cs file to open it.
Using the Refactor + Rename context menu command is the better approach, it doesn't forget to edit the other source files as well. It didn't work when you tried it because the damage was already done, the parts no longer had the same name.