I have the following code in an assembly.
public class a
{
public class b
{
public static string obj;
public static string result
{
get
{
return obj;
}
set
{
obj = value;
}
}
}
public class c
{
string result1;
public void invoke()
{
result1 = "abc";
b.result = result1;
}
}
}
I had referenced this in another application(say for eg: client app) and trying to access the value of obj
If i invoke a value by creating an instance of the class b how i can access the value it set in the previous scope without return from the invoked method?
Since everything involved is public, you can access this value outside the assembly as follows:
public class SomeExternalClass
{
public void SomeMethod()
{
string val = a.b.result;
}
}
Related
//Program.cs
public interface TestVal
{
//Input Param
string Input { get; }
//will return output
TestValRes ValidateRe(string input);
}
class MyClass : ITestVal
{
static void Main(string[] args)
{
var instance = new MyClass();
instance.Run();
}
public void Run()
{
ValidateRe("test");
}
public ITestValRes ValidateRe(string input)
{
return null; // return an instance of a class implementing ITestValRes here.
}
}
//TestvalRes.cs
public interface TestvalRes
{
string Input { get; }
bool IsValid { get; }
}
So I just want to pass a string to the TestVal, do validation and call TestvalRes to return whether it is Valid or not, and if Invalid, why? So the validation will be done in the first public interface - TestVal, however I still need to call it inside the Main(), right?
First off, I'd recommend following C# naming conventions and name your interfaces ITestVal and ITestValRes respectively.
Next, static method cannot call instance methods in the same class (without creating an instance and using that). You need to create an instance of the class and pass control of the application flow to that:
class MyClass : ITestVal
{
static void Main(string[] args)
{
var instance = new MyClass();
instance.Run();
}
public void Run()
{
ValidateRe("test");
}
public ITestValRes ValidateRe(string input)
{
return null; // return an instance of a class implementing ITestValRes here.
}
}
I would like to pass values from one class file to another class.
E.g:
Step1:
Class1.cs
public class Class1
{
public string LogedInPerson { get; set; }
public string Name
{
get { return this.LogedInPerson; }
set { this.LogedInPerson = value; }
}
}
Step2:
Value has been assigned in below method:
test.xaml.cs
public void assignValue()
{
Class1 obj = new Class1();
obj.LogedInPerson = "test123";
}
Step3:
I would like to get "test123" values from Class2.cs.
E.g:
public void test()
{
string selected_dept = ?? //How to get "test123" from here.
}
You can have variables class that includes public variables. Define instance of class1 in variables class .
public static class1 myclass=new class1();
in test.xml.cs set value
public void assignValue()
{
myclass.LogedInPerson = "test123";
}
in class2.cs
public void test()
{
string selected_dept = myclass.LogedInPerson;
}
Initialize Class1 outside assignValue() methos
Class1 obj = new Class1();
public void assignValue()
{
obj.LogedInPerson = "test123";
}
public string returnValue()
{
return obj.LogedInPerson;
}
if your second class name test.xaml then call it like this, but I don't think you can use class name test.xaml so use a nice name instead there eg: Class2
public void test()
{
test.xaml test = new test.xaml();
test.assignValue();
string selected_dept = test.returnValue(); //How to get "test123" from here.
}
I believe this question is more on the topic of basic Object Oriented Programming principles, not so much about WPF specific features. Therefore, I will provide you a non-WPF specific answer, as it will allow me to address your question in the most direct way.
In OOP, a method can return a result to the caller. So, for instance,
public string GetReturnObject(){
return "This is a return object";
}
You can create a new object and pass it back to the caller,
public void Test(){
string data = GetReturnObject();
}
And now data will be assigned the object that was returned from the method that Test() called. So, if you modify your AssignValue method by adding a return type and passing the instantiated Class1 object back to the caller, you will have the answer you need
public Class1 assignValue()
{
Class1 obj = new Class1();
obj.LogedInPerson = "test123";
return obj;
}
Hope that helps.
I have a class that is used for storing user data to a file. It works well, but can't really be placed into a PCL library easily. Outside of the PCL, it's all fine.
The class looks like this
public static class UserData
{
public static object GetPropertyValue(this object data, string propertyName)
{
return data.GetType().GetProperties().Single(pi => pi.Name == propertyName).GetValue(data, null);
}
public static object SetPropertyValue<T>(this object data, string propertyName, T value)
{
data.GetType().GetProperties().Single(pi => pi.Name == propertyName).SetValue(data, value);
return new object();
}
private static string pUserSettingsFile;
private static UserSettings userSetting;
public static bool AccountEnabled
{
get
{
return UserSettings.account_enabled;
}
set
{
UserSettings settings = UserSettings;
settings.account_enabled = value;
UserSettings = settings;
}
}
public static UserSettings UserSettings
{
get
{
if (userSetting == null)
{
if (File.Exists(UserSettingsFile))
{
userSetting = Serializer.XmlDeserializeObject<UserSettings>(UserSettingsFile);
}
else
{
userSetting = new UserSettings();
Serializer.XmlSerializeObject(userSetting, UserSettingsFile);
}
}
return userSetting;
}
set
{
if (value == null)
{
throw new ArgumentNullException("value is null!");
}
userSetting = value;
if (File.Exists(UserSettingsFile))
{
File.Delete(UserSettingsFile);
}
Serializer.XmlSerializeObject(userSetting, UserSettingsFile);
}
}
public static string UserSettingsFile
{
get
{
if (string.IsNullOrEmpty(pUserSettingsFile))
{
pUserSettingsFile = Path.Combine(GroupShootDroid.Singleton.ContentDirectory, "UserSettings.xml");
}
return pUserSettingsFile;
}
}
#endregion
}
public class UserSettings
{
public bool account_enabled { get; set; }
public string address { get; set; }
public string country { get; set; }
}
It's not rocket science, but does what I need it to do.
What I'm trying to do is use the Get/SetPropertyValue methods to return or set any of the properties within the class.
Currently, to access the Get/SetPropertyValue methods I'm using this
public string GetStringValue(string valToGet)
{
string rv = (string)UserData.GetPropertyValue(valToGet);
return rv;
}
public void SetStringValue(string name, string val)
{
UserData.SetPropertyValue(name, val);
}
On compiling though, the GetPropertyValue method is giving an error that No overload for method GetPropertyValue takes 1 argument with the SetPropertyValue complaining that there isn't an overload that takes 2
I'm not sure that the code I'm using will do what I need it to do (from what I've read on here it should be), but I'm more perplexed as to why the errors are showing.
Is there a better way to do what I'm trying to do? The application is a Xam.Forms app, so the PCL accesses the class through an interface using injection.
You are defining extension method, you need an instance of the class to call them:
var o = new Object();
string rv = (string)o.GetPropertyValue(valToGet);
// or, but no sure
string rv = (string)UserData.GetPropertyValue(o, valToGet);
or more probably in your case:
public string GetStringValue(string valToGet)
{
string rv = (string)this.GetPropertyValue(this, valToGet);
//or
//string rv = (string)UserData.GetPropertyValue(this, valToGet);
return rv;
}
I think you're getting confused between the UserData class and the object class. Your extension methods extend object.
I have a static Class and within it I have multiple public static attributes. I treat this class as my global class.
However now I need to treat this class as a variable so that I can pass it to a method of another class for processing..
I can't instantiate this class.. So in effect I can only assign the variables inside this class.
Is my understanding correct or am I missing something?
public static class Global
{
public const int RobotMax = 2;
// GUI sync context
public static MainForm mainForm;
public static SynchronizationContext UIContext;
// Database
public static Database DB = null;
public static string localDBName = "local.db";
public static Database localDB = null;
public static Database ChangeLogDB = null;
public static string changeLogDBName = "ChangeLog.db";
}
Let say I have a class like this, and I need to somehow keep a copy of this in another class maybe
public static class Global_bk
{
public const int RobotMax = 2;
// GUI sync context
public static MainForm mainForm;
public static SynchronizationContext UIContext;
// Database
public static Database DB = null;
public static string localDBName = "local.db";
public static Database localDB = null;
public static Database ChangeLogDB = null;
public static string changeLogDBName = "ChangeLog.db";
}
I need to copy the contents from Global to Global_bk.
And after that I need to compare the contents of the two classes in a method like
static class extentions
{
public static List<Variance> DetailedCompare<T>(T val1, T val2)
{
List<Variance> variances = new List<Variance>();
FieldInfo[] fi = val1.GetType().GetFields();
foreach (FieldInfo f in fi)
{
Variance v = new Variance();
v.Prop = f.Name;
v.valA = f.GetValue(val1);
v.valB = f.GetValue(val2);
if (!v.valA.Equals(v.valB))
variances.Add(v);
}
return variances;
}
}
class Variance
{
string _prop;
public string Prop
{
get { return _prop; }
set { _prop = value; }
}
object _valA;
public object valA
{
get { return _valA; }
set { _valA = value; }
}
object _valB;
public object valB
{
get { return _valB; }
set { _valB = value; }
}
}
So on my main form, how do I go about calling the compare method and passing the static Global class inside?
example: extentions.DetailedCompare(Global, Global_bk) ? Of course this would give me an error because I cant pass a type as a variable.
Please help me, this is driving me nuts...
How about the singleton pattern ? You can pass reference to shared interface (IDoable in exable below) and still have just one instance.
I.E.:
public interface IDoable {
int Value { get; set; }
void Foo();
}
public static class DoableWrapper {
private MyDoable : IDoable {
public int Value { get;set; }
public void Foo() {
}
}
private static IDoable s_Doable = new MyDoable();
public static IDoable Instance {
get { return s_Doable; }
}
}
Singleton is the way to go here. You can do it like this:
internal class SomeClass
{
private static SomeClass singleton;
private SomeClass(){} //yes: private constructor
public static SomeClass GetInstance()
{
return singleton ?? new SomeClass();
}
public int SomeProperty {get;set;}
public void SomeMethod()
{
//do something
}
}
The GetInstance Method will return you a SomeClass object that you can edit and pass into whatever you need.
You can access the members with classname.membername.
internal static class SomeClass
{
public static int SomeProperty {get;set;}
public static void SomeMethod()
{
//do something
}
}
static void main()
{
SomeClass.SomeProperty = 15;
SomeClass.SomeMethod();
}
The only way you are going to obtain a variable with the "class" information is using reflection. You can get a Type object for the class.
namespace Foo {
public class Bar
{
}
}
Type type = Type.GetType("Foo.Bar");
Otherwise, if you are really describing a class "instance" then use an object and simply instantiate one.
C# offers no other notation for class variables.
I have something like this:
class BaseArg { }
class DerivedArg : BaseArg { }
interface IDoSomething
{
void DoSomething();
}
class A : IDoSomething
{
public BaseArg Value { get; set; }
public A(BaseArg value)
{
this.Value = value;
}
public static A Create(BaseArg arg)
{
return new A(arg);
}
public static B Create(DerivedArg arg)
{
return new B(arg);
}
public virtual void DoSomething()
{
}
}
class B : A
{
public DerivedArg DerivedValue { get; set; }
public B(DerivedArg value)
: base(value)
{
this.DerivedValue = value;
}
public override void DoSomething()
{
// does something different from A.DoSomething()
// uses additional stuff in DerivedArg
}
}
However, even when I do this:
DerivedArg arg = new DerivedArg();
A a = A.Create(arg);
A.Create(BaseArg arg) is called (and thus A is created, which was not the intention).
Am I missing something here? If so, how should I rewrite this without using weird stuff such as conditions on arg as DerivedArg.
The correct factory method is getting executed. Set a breakpoint inside of:
public static B Create(DerivedArg arg)
{
return new B(arg); /* set breakpoint */
}
It appears to you that it isn't being executed since you've defined the local variable of type A:
A a = A.Create(arg);
public static B Create(DerivedArg arg) is being called properly and an instance of type B is being returned and boxed as type A.