The idea of the code is to make a console to parse some commands. And have some commands with arguments and others no. Without the static the program return other error that is...
I'm trying to make a "Rain" application, by drawing some lines on the form, and then they must fall. So here is my start code:
public partial class Form1 : Form { public Form1() { InitializeComponent(); } Random r = new Random(); Graphics paper; Line line;
[Code] ....
So when I start debugging I get the "Object reference not set to an instance of an object." error. If I remove the comments lines at "timer1_Tick" this error doesn't appear of course. What can I do to escape from this because it follows me everywhere I go />. I tried to make with arrays, but same problem.
So on lines 36 - 39 (The commented out functions) is where I'm sure is causing this error because once I don't comment them out pretty much everywhere Flink or Rlink is used or defined I get this error.
Code: class A { std::map<std::string, Unit*> aMap; class B
[Code] .....
This code snippet results in "A non-static member reference must be made relative to a specific object". When I make callA() static, this error goes away, but there is problem with aMap.
I am modifying a set of static variables inside of the class's member function. The static variables are private. An example of what I'm doing is as below,
utilities.h ----------- class utilities { private: static int num_nodes;
public: void parse_details(char* );
[Code] ....
I get a compilation error in the function void utilities::parse_details(char* filename)
which says: undefined reference to `utilities::num_nodes'
I am using the above code to retrive an item selected by user,But this line is giving an exception "Null Reference Exception, Object reference not set to an instance of an object"
I've been trying for more than one month to access a method found in a library called libcocosnas_static.a. I'm using Cocos2d-X version 2.0.4. The library has been used many times by my company to make games using cocos2d-1.0.1-x-0.12.0 without any problem.
This is what I've done: 1- I added the include paths of the library to both eclipse and Android.mk 2- Included the .h file using #include "NASPlatformUtil.h" 3- Added the libcocosnas_static.a file to the proj.androidobjlocalarmeabi folder 4- Added "LOCAL_WHOLE_STATIC_LIBRARIES += cocosnas_static" to the Android.mk file 5- Called the function using: NASPlatformUtil:: openUrl("http://xxx.xxx.com/");
I can right click on the function, click Open Declaration and get it without any problem, but the compiler keeps on giving me that dreaded error...
class DataBase { // Change the connection path here to your own version of the database public SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)v11.0;AttachDbFilename=|DataDirectory|UberDatabase.mdf;Integrated Security=True;"); public DataBase() { } }
And in the same namespace as this class I have a form that calls it like so:
DataBase dBase = new DataBase(); SqlCommand trythis = new SqlCommand("Register", dBase.con);
However, I'm getting the field initializer error on dBase.con. I'm not sure why, but when I call the database from another file (program.cs) it works fine this way.
How to tell whether a variable has been accessed in memory, no matter what it's been used for... Whether it's actually been set to something else, or whether it's been get for an operation or function call that doesn't actually do anything to affect the variable itself. Either way the variable has been "accessed" for something.
I'm not entirely certain that it's possible to detect a program getting the variable but I know that programs exist where they can trace what has accessed a certain part of memory... CheatEngine is one example, although I'm not entirely sure whether this can only detect changes in the variable and then trace what did it
Suppose I have a class "A", which has a method "void AMP_call()" that calls paralel_for_each in which another method, "float amp_function(float) restrict(amp)". When I call that method, can it then use members of "A"?
class A { void AMP_call(); float amp_function(float) restrict(amp); // do something on a device float allowed_variable; std::vector<bool> not_allowed;
[Code] ....
Another way to frame my question, perhaps to make it easier to understand what I am after, would be that I want to know what happens if an amp-restricted method is called where the body of the class itself (which is not amp-compatible and afaik doesn't have to be since it's not passed to the device) may contain members that are not amp-compatible.
All of the msdn blogs I could find deal with which functions and methods can be called from within a parallel_for_each loop, but not with which variables are available to the lambda function itself.
I'm trying to write a simple Delegate class with a Bind() and Invoke() function. For now it only needs to support a void class function with no parameters. I've searched around and found quite a few exmaples, though, those class are heavily templated and I lose track trying to simplify it.
So far my code is following:
Code: #include <windows.h> class Test { public: void DoSomething() { MessageBox(NULL, L"Test::DoSomething!", NULL, 0);
[Code] ....
The part I am having difficulty with is assigning &Test::DoSomething to the m_Callback variable.
&tObject::DoSomething works, yet _Callback which I pass &Test::DoSomething to does not work.
I'm redesigning some code and I'm wondering what the best ways to store and access certain data is. The characteristics are as followed:
1) Based on data from a file, a distance matrix (N x N) is calculated. 2) Once the matrix is complete, the data will never change (unless a new file is read, but I can work around that by iteratively calling the problem with a new datafile on as command line parameter). 3) The data from the matrix is accessed billions of times from pretty much every other line of code.
In my old version, I had a class "Data" which a sub-class "Data::Distance" and I would put a reference in every other class that needed it. Now, my class hierarchy will be much flatter (basically all logic will be in one class; other classes will be POD structs).
Given the characteristics of the Distance table, is there a way to store them in a very efficiently-accessible way? Does it matter if it's stored in the main class where all the action happens in contrast to being a different class? Does making it static improve the performance? Casting it to const? Anything?
Again, the data is accessed billions of times so even minor differences can save a lot of time.
I currently have globally declared arrays, which are accessed by multiple functions. I want to turn the program so that the arrays are no longer globally declared, but are passed to functions by reference.
I have one problem with passing the arrays: I found that, through debugging, I HAVE TO resize the array when I pass it by reference. For instance, I was using int a[10] when it was globally declared, when it is passed by reference with size 10, it does not work, instead it should be higher than 10 (certain number). Why is this happening? I do not get it...
A static function can be called in relation to a particular object by a statement such as the following:
aBox.Afunction(10);
The function has no access to the non-static members of aBox. The same function could also be called without reference to an object. In this case, the statement would be:
CBox::Afunction(10);
where CBox is the class name. Using the class name and the scope resolution operator tells the compiler to which class Afunction() belongs."
What are the workarounds for accessing the non-static member variables of some class(Say A) inside static member functions of another class(Say B)? I am coding in c++. Class A is derived with public properties of class B. Any pointers?
"A nested class has free access to all the static members of the enclosing class. All the instance members can be accessed through an object of the enclosing class type, or a pointer or reference to an object."
How can the members be accessed through an object of the enclosing class type? I understand the pointer and reference part because for them you dont need the full definition, but for creating a object you do?
Also it has free access to all static members because the nested class is part of the enclosed class and with static it exists in everything inside the enclosing class? Right or am I missing something?
1. Is that mean that Do() is only available for use by Dog itself because Dog is 'oryginal' Dog, and if i create new dogs - instances of oryginal Dog (dog1, dog2 ...) they cant access because Do is only available fo 'oryginal' one? Is that correct thinking?
2. If i would want to have something common (e.g value) for all dogs is that good way to create static field/method for Dog instead of non-static once then all instances of Dog would access Dog static member to get/change it? Just stupid example: static method GetAmountOfLegs() which return 4 Then all instances can take/call that value from Dog. Is that correct thinking?
class BoundingBoxTest : public DemoApplication { public: #ifdef DYNAMIC_CHARACTER_CONTROLLER btCharacterControllerInterface* m_character;
[Code] ....
I am creating the object by calling : BoundingBoxTest::Create();
Do I make a getter to retrieve the demo object or do I build on the Create() method... So that it will return the instance if it is not null. and creates one if there is none?
