I'm getting a compiler error saying that "Acme.Business.User" is not defined.
I have a class library project called "Acme.Business" that has "Acme.Business" as the assembly name and root namespace as well. None of the classes use the "Namespace" keyword, so they all should exist in the namespace "Acme.Business".
I also have a class library project called "Acme.Web" that has a project reference to "Acme.Business". Again "Acme.Web" is the project name, assembly name, and root namespace.
Here's the weird part. If I add a class to "Acme.Web" I can type "Imports Acme." at the top and see both namespaces appear in intellisense like you'd expect, but if I try to do "Dim x as New Acme.Business.User" then "Business" doesn't show up in intellisense and I get an error saying "Acme.Business.User" is not defined.
I can't see what I'm doing wrong! Please help. Thanks.
I think you may be misunderstanding how project default namespaces work. The default namespace is a project file setting that simply tells Visual Studio what namespace to add to each file when you add a new class file to the project. If you have removed all of these namespaces from the code files then your types do not exist in that namespace.
This means that all of your types in the Acme.Business assembly live in the global namespace which is probably not what you want. In order to get the desired behavior you will need to add the namespaces back into your code files as that is the only way the compiler will create type names with that namespace.
OK, I figured out that the behavior I was seeing was because I was declaring namespaces within the code in Acme.Web the way I was used to in C# which is to fully qualify it, ie. Namespace Acme.Web.UI.WebControls. I didn't realize that in VB.NET it's building on top of what was specified for the root namespace. I removed the portion that was specified in the "root namespace" setting of my project and it started working. So my namespaces in code for Acme.Web now look like Namespace UI.WebControls.
Related
I am trying to import Windows.Graphics.Printing3Din VB.Net; however, i get the following warning:
Namespace or type specified in the Imports 'Windows.Graphics.Printing3D' doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases.
What am I doing wrong?
I figured it out eventually. It can be done by importing these two references:
1 - System.Runtime.WindowsRuntime.dll located in C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETCore\v4.5
2 - Windows.winmd located in C:\Program Files (x86)\Windows Kits\10\UnionMetadata\
Refer to this Windows Blog article for more information.
You have to reference an assembly that contains a declaration for at least one type that is a member of that namespace. Whatever type you're trying to use, open the MSDN documentation page for that type and it will tell you what assembly that is. You can then reference it on the References page of the project properties.
That said, it appears that that namespace is part of the UWP. Is this a UWP app that you're building? If not then that namespace will not be available at all. If it is then I think you should already have an appropriate reference, which makes me think that it's not.
in Visual Studio 2017 I have a solution with aspnet core project and about 10 net core libraries referenced to each other.
One of the libraries is xUnit test project. It referenced to another project it should use as aim for testing.
For example I have:
Project: MyProject.Domain
Test Project: MyProject.Domain.Tests
MyProject.Domain.Tests is referenced to MyProject.Domain.
In these projects I have classes with namespaces like project names.
So the strange thing happened when I can use public class from MyProject.Domain WITHOUT using MyProject.Domain.
Can anybody explain it ?
If I understand you correctly, you're wondering why a type in the namespace MyProject.Domain.Tests can access types in the namespace MyProject.Domain without any usings. The reason for that is that the specification says so. From Namespace and type names (edited by removing irrelevant parts):
The meaning of a namespace_or_type_name is determined as follows:
If the namespace_or_type_name is of the form I:
For each namespace N, starting with the namespace in which the namespace_or_type_name
occurs, continuing with each enclosing namespace (if any), and ending
with the global namespace, the following steps are evaluated until an
entity is located:
If N contains an accessible type having name I, then:
The namespace_or_type_name refers to the type.
When I try to Imports System.Web.Script.Serialization, I get an error in VB 2010 that says:
Warning: Namespace or type specified in the Imports System.Web.Script.Serialization doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases.
Not sure why I can't import it.
You might be missing an assembly reference to System.Web.Extensions.dll. Add this reference to your project, then try again.
Generally speaking, when you encounter this issue, go to the .NET API reference page of the type you want to use — for instance, JavaScriptConverter — and look out for the Namespace and Assembly hints (make sure you're looking at the page for the .NET framework version that you are using):
Namespace: tells you what to put in the Imports directive.
Assembly: tells you what assembly you need to reference in your project (e.g. go to Solution Explorer, locate References, and select Add Reference… from the context menu).
Also make sure to check the "Target Framework" in the project properties. If you are targeting a "Client Profile" framework then the assembly System.Web.Extensions.dll will not be available to add as a reference to your project.
I created a new Metro Split App in C++ using VS2012 on Win8 (both RC). Everything compiled and worked out of the box. I then changed went through and changed the generated namespaces to my own. After some trials and tribulations, I got everything to compile with no warnings, errors, nor messages. The app (as it comes in the project template) runs fine.
However, if I try to edit either of the generated xaml files (ItemsPage.xaml or SplitPage.xaml) I get a "Markup error" on the first line:
The name "LayoutAwarePage" does not exist in the namespace "using:A.B.Product.Client.Common".
The definition of the class is:
namespace A{ namespace B { namespace Product { namespace Client { namespace Common
The code compiles fine, and runs fine. This only happens in design mode.
UPDATE: I added a new xaml file and (after fixing up the namespaces again) everything worked.
Please let me know if any additional information is needed.
The name of the WinMD file produced by your project must be some prefix of the namespaces in which the public WinRT types are defined. Given that your type is in the A.B.Product.Client.Common namespace , the WinMD file must have one of the following names:
A.winmd
A.B.winmd
A.B.Product.winmd
A.B.Product.Client.winmd
A.B.Product.Client.Common.winmd
The public types must also be defined in the WinMD file with the longest prefix that matches the namespace. So, if you have both A.winmd and A.B.winmd, the type A.B.MyClass must be defined in A.B.winmd.
So, why does your code work at runtime but not in the designer? The naming rules for public types only apply to types defined in Windows Runtime components (for C++, DLL files), not for applications (EXEs).
However, to be able to instantiate your user-defined types (including LayoutAwarePage), the designer will load your project's EXE as a DLL, so the naming rules must be followed.
I had a similar bug, but then I closed VS, deleted the .suo, and reloaded the project and everything worked just fine.
I've googled for creation of namespaces and found some very useful examples, what these examples didn't have is how do I compile and implement my created namespace on my system so I can include it from my various applications.
So for example, if I create a namespace to load a config file from my application path and insert it to an array, Do i need to include the namespace on any project I use or is there a way to make it part of my environment?
You're thinking of Class Library (DLL) projects.
When you start up a new Visual Studio project, select Class Library rather than Windows Form project. This will compile your namespaces as a DLL (exposing your public classes), which can be referenced in other projects.
If you want to include a namespace that you created you have to add a reference to your project first. If you have compiled your code into a .dll file, then simply add the reference to the .dll file to your project and then at the top of your classes put the "Imports [Namespace]". If you haven't compiled your namespace, add the project (with the namespace that you created) to your solution, add the reference to it (under the Projects tab), and then use the Imports statement.
You are confusing the concept of a namespace with the concept of a project, especially of a class library project.
A class exists within a namespace. If no namespace is defined, then the class still exists within the global namespace (the one with no name).
In any case, it's classes that do the work. Namespaces are only so that you can have a class named Book, and I can have a class named Book, and so that TriDat.Book can exist at the same time as JohnSaunders.Book.