This question already has answers here:
Resolving an ambiguous reference
(4 answers)
Closed 7 years ago.
How can I see which using statements provides a class in Visual Studio 2013?
And how can I detect conflicts?
I have this kind of code
foo.cs:
namespace foo
{
class XmlConverter
{
}
}
bar.cs:
namespace bar
{
class XmlConverter
{
}
}
And I need to use both foo and bar namespaces (both have multiple classes).
EDIT: I know I can rename my classes (or use aliases) but how can I detect this issue(wrong class being used) ? Is it even possible ?
You can use using aliases for this. Syntax looks like this: using MyAlias = MyNamespace.A.
See Using alias directives and/or How to: Use the Global Namespace Alias
In your case:
using FooConverter = foo;
using BarConverter = bar;
public ThirdPartyClass
{
public void SomeMethod(FooConvert.XMLConverter fooConv, BarConverter.XMLConverter barConv)
{
}
}
of course that only makes sense when your actual namespace consists out of at least two parts or the name of the namespace is much longer and could be shortened without losing readability.
For example shorten System.IO to SysIO or ThisIsMyNamespace to MyNamespace. Else it's just more yping. With your example it makes more sense to just not have a using statement.
What is not possible is to somehow have the compiler 'detect' whether you are using foo's XMLConverter or bar's XMLConverter without putting some kind of classifier (be it alias or entire namespace) in front of the classname.
To OP's update: The compiler will let you know that something is wrong. The message is Class1 is an ambiguous reference between Foo.Class1 and Bar.Class1.
If there is a conflict then the C# will complain with an error. In this case your code should use a fully qualified name as in new foo.XmlConverter or new bar.XmlConverter.
However this is bad practice. If you can you should rename classes to FooXmlConverter and BarXmlConverter.
Related
This question already has answers here:
How can I find all usages of a namespace and its members?
(2 answers)
Closed 2 years ago.
EDIT3: Question rewritten for future reference, thanks to BahJiy
Is there a Visual Studio (or ReSharper) command like "Find Usages" to find class usages from using directive?
Find Usages only shows the reference of the namespace itself (and thus "the only usage" as per below screenshot).
When I comment out that using System.Reactive.Linq line as per below, Observable indicates an error that it doesn't exist in the current context.
I could comment out the using directive and check errors like above, is there a better way than checking errors one by one?
Answer: Find Usages does it, cursor position matters
As mentioned below in the comment to the answer, the cursor position needs to be at using, rather than the namespace.
Old question body
Is there a Visual Studio (or ReSharper) command that tells me which methods are coming from SomeNamespace.SomeClass defined by using SomeNamespace.SomeClass within using file?
I would like to check the use case when I encounter some unexpected namespace.
Find Usages or All References on the using directive only shows other directives.
I could delete the very using directive and check for errors within the file, but I must be ignorant of a better way...
EDIT + EDIT2:
An example may help to clarify the situation better.
SomeClass.cs
namespace SomeNamespace {
public static class SomeClass {
public static string SomeExtensionMethod(this string s){
// some implementation
}
/*
More extension methods
*/
}
}
Consumer.cs
using SomeNamespace.SomeClass
namespace OtherNamespace {
public class Consumer {
public void Consume(){
string id = "someid";
string after = id.SomeExtensionMethod;
}
/*
More extension methods from SomeClass used
*/
}
}
The question is, when I find some Consumer having a using SomeNamespace.SomeClass, what's the best way to check where the underlying methods are used?
Is there a command similar to Find Usages to get all the methods coming from SomeNamespace.SomeClass under Consumer class?
Normally just check your using. Visual Studio only allow a method/class call from one Namespace. If there are two more more method of the same name in multiple of your Namespace that you are using, Visual Studio will force you to specify the Namespace explicative in your call.
i.e.
using Name1;
using Name2;
namespace Class1 {
class Testing {
public Testing {
// this method only exists in Name1
Method1 ( );
// this method exist in both Name1 and Name2
Name1.Method2 ( );
Name2.Method2 ( );
}
}
}
So if you see only
using SomeNamespace;
you will know that any classes that may come from that namespace is specifically from SomeNamespace.
If there was another class of that same name but also in a different namespace, Visual Studio will force you to type in that namespace when calling.
So if you see that you usings are normal and there are no random
RandomNamespace.Class1 class1 = new RandomNamespace.Class1 ( );
You know for sure that nothing is out of the ordinary.
you want to know if a imported namespace is neccessary to be imported, because types from that namespace are used? if its that have a look in the addon "Productivity power tools" e.g. There is an option to remove and sort usings on save
This question already has answers here:
How can I find all usages of a namespace and its members?
(2 answers)
Closed 2 years ago.
EDIT3: Question rewritten for future reference, thanks to BahJiy
Is there a Visual Studio (or ReSharper) command like "Find Usages" to find class usages from using directive?
Find Usages only shows the reference of the namespace itself (and thus "the only usage" as per below screenshot).
When I comment out that using System.Reactive.Linq line as per below, Observable indicates an error that it doesn't exist in the current context.
I could comment out the using directive and check errors like above, is there a better way than checking errors one by one?
Answer: Find Usages does it, cursor position matters
As mentioned below in the comment to the answer, the cursor position needs to be at using, rather than the namespace.
Old question body
Is there a Visual Studio (or ReSharper) command that tells me which methods are coming from SomeNamespace.SomeClass defined by using SomeNamespace.SomeClass within using file?
I would like to check the use case when I encounter some unexpected namespace.
Find Usages or All References on the using directive only shows other directives.
I could delete the very using directive and check for errors within the file, but I must be ignorant of a better way...
EDIT + EDIT2:
An example may help to clarify the situation better.
SomeClass.cs
namespace SomeNamespace {
public static class SomeClass {
public static string SomeExtensionMethod(this string s){
// some implementation
}
/*
More extension methods
*/
}
}
Consumer.cs
using SomeNamespace.SomeClass
namespace OtherNamespace {
public class Consumer {
public void Consume(){
string id = "someid";
string after = id.SomeExtensionMethod;
}
/*
More extension methods from SomeClass used
*/
}
}
The question is, when I find some Consumer having a using SomeNamespace.SomeClass, what's the best way to check where the underlying methods are used?
Is there a command similar to Find Usages to get all the methods coming from SomeNamespace.SomeClass under Consumer class?
Normally just check your using. Visual Studio only allow a method/class call from one Namespace. If there are two more more method of the same name in multiple of your Namespace that you are using, Visual Studio will force you to specify the Namespace explicative in your call.
i.e.
using Name1;
using Name2;
namespace Class1 {
class Testing {
public Testing {
// this method only exists in Name1
Method1 ( );
// this method exist in both Name1 and Name2
Name1.Method2 ( );
Name2.Method2 ( );
}
}
}
So if you see only
using SomeNamespace;
you will know that any classes that may come from that namespace is specifically from SomeNamespace.
If there was another class of that same name but also in a different namespace, Visual Studio will force you to type in that namespace when calling.
So if you see that you usings are normal and there are no random
RandomNamespace.Class1 class1 = new RandomNamespace.Class1 ( );
You know for sure that nothing is out of the ordinary.
you want to know if a imported namespace is neccessary to be imported, because types from that namespace are used? if its that have a look in the addon "Productivity power tools" e.g. There is an option to remove and sort usings on save
I have been looking around for a while now to see how can I enforce my C# projects to have full namespace path.
For example actual if namespace for class X is Foo.Bar.Car.Dealer when doing Ctrl+. in visual studio it sometimes puts statement like using Car.Dealer; this specially becomes a problem with multiple projects solution. I have been looking around for StyleCop rule or something that might help me get this done.
Any help or ideas?
EDIT
The above statement holds true only if the using class falls under same namespace prefix. Here is complete code example:
File: X.cs
namespace Foo.Bar.Car.Dealer {
class X {}
}
File: UsingClass.cs
namespace Foo.Bar.Another.ClassPath {
using Car.Dealer;
class UsingClass {
private X _x;
}
}
The VS picked using Car.Dealer but I want to enforce using Foo.Bar.Car.Dealer
I do not know about versions prior to 2012, but from then on the icon that pops up for action upon coming across an unknown type offers both adding the namespace via using directive or to simply prefix the type being referenced by the full namespace.
If you do not want to add the namespace via using directive (which would look like using Foo.Bar.Car.Dealer;),
then in your example you simply need to reference your type X as Foo.Bar.Car.Dealer.X.
Example:
//assuming your X type is instantiable
Foo.Bar.Car.Dealer.X myX = new Foo.Bar.Car.Dealer.X();
This question already has answers here:
Importing nested namespaces automatically in C#
(7 answers)
Closed 9 years ago.
in c# if I want to add other System namespaces why do I need to call each namespace?
For example
if I want to call the System.Text namespace I have to use:
using System;
using System.Text;
why cant I just use using System?
Why do I also have to call using System.Text?
Why cant I use all System namespaces by just using System?
Why we use System for all namespace ?and what the meanings of system ?
the System namespace refers only to the files directly found under System. It does not automatically include all System.* namespaces. This is intended, since these are specialized namespaces which aren't needed in every class. Not every project automatically needs the System.Web namespace, for example.
You actually just need
using System.Text;
if you only want to use the System.Text namespace.
Within the System namespace, there are various types, eg System.DateTime. System.Text is not in System though, it is a separate namespace.
The confusion is caused by there being types at each "level" of a namespace. This means eg System.DateTime and System.Text both appear to be in System, when in reality the former is a type in System and the latter is a completely different namespace.
Here's a visual example that may help you out a little.
Basically, you can't access the namespace .Text from namespace .System because the methods contained within the .Text namespace do not exist in the .System namespace.
namespace OuterNamespace
{
public class DoStuff
{
public DoStuff()
{
//This DoStuff is different...
}
}
namespace InnerNamespace
{
public class DoStuff
{
public DoStuff()
{
//than this DoStuff.
}
}
}
}
public class Test
{
public Test()
{
//This "DoStuff" class
OuterNamespace.DoStuff outerStuff = new OuterNamespace.DoStuff();
//Is different than this "DoStuff" class
OuterNamespace.InnerNamespace.DoStuff innerStuff = new OuterNamespace.InnerNamespace.DoStuff();
}
}
Because they're different namespaces.
This article explains how to use Namespaces. Especially the example regarding Fully Qualified Names might be interesting to you.
System and System.Text are two different namespaces and that's why you had to refer both.
The System namespace contains fundamental classes and base classes that define commonly-used value and reference data types, events and event handlers, interfaces, attributes, and processing exceptions
The System.Text namespaces contain types for character encoding and string manipulation. A child namespace enables you to process text using regular expressions.
Now if you are confused about naming style then I would stick to Microsoft naming convention since it clearly isolate relating types and easy to iterate. This make stepped type iteration than listing all CLR types within one System namespace.
More about namespaces
I am creating a little Math library for myself contained within a single project and am running into some issues with namespaces. I have the project MyMathLib and the top level namespace:
namespace MyMathLib
{ ... }
and in a separate file...
namespace MyMathLib.Addition
{ ... }
and...
namespace MyMathLib.Subtraction
{ ... }
In the MyMathLib.Subtraction namespace I have a method that needs to use a static method SomeClass.Work() defined in MyMathLib.Addition so I included using MyMathLib.Addition at the beginning of the Subtraction file. But when I try to use the method it would like me to first qualify it with Addition.SomeClass.Work() and I want to be able to just type SomeClass.Work(). What am I doing wrong?
Thanks!
EDIT
Thanks for the suggestions! In each file, I actually named the class after the namespace (i.e. in the namespace MyMathLib.Addition is a static class Addition and in MyMathLib.Subtraction there is a static class Subtraction). Apparently this is what caused the issue (looking back, I should have stated this instead of using SomeClass). If I change the namespace to MyMathLib.MyAddition while keeping the static class as Addition, the using MyMathLib.MyAddition works as I want; that is, I can now just type Addition.Work() in my static Subtraction class. I've seen classes named the same as it's containing namespace before, could someone maybe explain why this is causing an issue? Shouldn't the compiler be able to determine whether I want to use the namespace or the class from the context of the code?
I'm guessing that you either have two classes called SomeClass that are both in namespaces you reference, or you have a variable or property named SomeClass. Either of these situations would make it impossible for the compiler to know that you're trying to call the static MyMathLib.Addition.SomeClass.Work() method, but the specific solution the compiler is suggesting makes it seem more likely to be the former.
Update
Seeing your edit, that makes sense. If you were using these in a namespace outside of MyMathLib, then you would still be able to avoid this namespace conflict. However, because you are inside the MyMathLib.Subtraction namespace, the compiler will implicitly consider any portion of the namespace "above" you to take precedence over class names. In this case, when you say "Addition", the compiler will look for the following items to resolve the name:
A class explicitly identified by a using ... = ... directive.
MyMathLib.Subtraction.Addition namespace.
MyMathLib.Addition namespace.
Addition namespace.
Any classes in the namespaces identified by using statements.
In this case, you're hitting #3 before #4, so you should be able to work around it either by renaming the class or namespace, or by using Yahia's suggestion (#1):
using Addition = MyMathLib.Addition.Addition;
Update 2
After looking at the article you linked to, it sounds like the explicit using statement still won't work. I guess item #1 actually gets evaluated down around item #4 instead. Bummer. You can use an alias to give the class a different name locally:
using Add = MyMathLib.Addition.Addition;
...
var add = new Add();
But the best solution is still probably just to avoid the namespace collision entirely by changing your namespace or class name.
try putting additionally the floowing line into your substraction source
using SomeClass = Addition.SomeClass;
http://msdn.microsoft.com/en-us/library/dfb3cx8s.aspx
http://www.blackwasp.co.uk/NamespaceAliasQualifier.aspx
Sounds like you're in the Subtraction namespace...add this to the top, inside the namespace declaration:
using Addition;
That should do the trick.