I am working on a project in a group at a university. We are creating a GUI in Java where the user can enter parameters. Then we want to be able to pass these parameters to a function inside our C/C++ program, that does the rest. How do I do this? So far I have managed to call a simple helloworld-function by using JNI, dll and a javah tool that create a header file from a java file. I define the helloworld-function in C and call it from Java.
Java file:
package helloworld; public class HelloWorld { private native void print(); public static void main(String[] args) {
[Code] ....
My problem is that I do not know how to call the helloworld-function with parameters. I guess that this is a special case when using JNI and a . dll. How do I pass simple char- and int-arguments from the Java class to the helloworld-C-function?
Here is a working C++ program and its output that reads the names of a certain number of functions whose names are written in a disk file that provides the control parameters in a near-real time fashion. Based on this information, the program calls those functions whose names were given in this text file as parameters. The method I have used is to build a map of functions that connects the names of the functions to the actual functions. Once this map is created, then it is very easy to iterate in such a way that only those selected functions are called.
So far this is working well, and it makes the logic of the code easier because ultimately there will be a large inventory of functions (probably hundreds of functions), and this way of pre-building a map of functions avoids writing hundreds of if statements in the code. Of course, pre-building this reusable map in the background is still equivalent to writing that many if statements, but at least it makes the code very compact and much more automatic, since it is done only once.
But I now have a related question: In this case (when the selected subset of functions to call is given as incoming data as in this example), does C++ make it possible to avoid using maps of functions, by directly applying the string variable that holds the name of the function in order to call the original function immediately For instance, if a string variable s = "MyFunction", then is there a more direct way of using this string as if it were the actual function whose name is spelled exactly in that way? This would make the code even more compact.
Here is the sample test code for the map of functions, and its output:
First of all here is the text file "FileForNamesOfFunctions.TXT" that contains the part of the "data", which is the set of functions select from from the inventory and only call these:
Code: function2 function3 function5 And here is the C++ code that uses this "data":
This week we are learning to use templates, and I don't understand how to call my member functions with my template based class. I tried the standard convention of calling member functions, but I keep getting an error saying name following"::" must be a class or namespace name. I'm thinking my problem lies with my typename T, but I am unsure. Line 16 is where I am getting tripped up.
#include "stdafx.h" #include <iostream> #include <string> using namespace std; template<class T> T Set { public:
I want this programming to call functions choose between a customer type and call the relevent function to calculate the final price but it is not calling the functions.
Recently started working with C #, and do not know how to call a page using MenuStrip, for example, when you click any of the menus, I need to call another page ...
Afterwards I'm using this as a check throughout my application:
if (dbCount > 0) { // do something }
When I execute this code I'm getting the following error: "Operator '>' cannot be applied to operands of type 'method group' and 'int'"
So I'm guessing it has something to do with the cast of the dbCount-object but I don't understand why as I already stated that the count-object to be an Int32.
I have been poking around with some Java source code that I'd like to port to C++
Here is something I am trying to do
Code: namespace AStar_NS { //... class Node { public: Node() { f = 0; g = 0; h = 0;
[code]....
Here I just want to compile the code pile and want to know what will be going on inside the debugger later on.The IDE didn't work that much. If I put AStar_NS::Node inside the TimeAStar_NS::Node's methods, the compiler will get confused. If I put TimeAStar_NS::Node there, the code also never compiles.
There are many types of nodes and transitions inside the Java code, so I can't even identify which is which inside the IDE even with IDE. There are many types of namespaces (as I create them to try to pull the code apart in order to comprehend them) And I can't reduce the compile errors down until 20 errors.
(The code is way too complicated, I can't even analyze it, I have to reply on the debugger) I want to know if Node inside the methods should be an instance of TimeAStar_NS::Node or AStar::Node or others. Should I create a more generic type of Nodes and Transitions above AStar_NS::Node and TimeAStar::Node. I know C++ and Java are quite different and difficult to port sometimes.
I'm building a simple little program for minecraft to reduce the repetitiveness, I'm using getpixel, it's slow, but i only need to grab about 6-12 pixels.
but the problem is, I can get the pixel data if I capture from the entire desktop display, but as soon as I tell it to grab from the active window (wich goes MUCH faster) it doesn't return any colour value's.
I'd rather not have to use getDIBits or program in java or anything since I want to keep it fairly kiss, and if it can't be done, then.. ah well, I'll just grab from the entire desktop, speed isn't to much of an issue, but it'll be a pain to keep the window at the same place.
Code: #include <Windows.h> #include <iostream> using namespace std; // vvv Ignore this, it's just used for retrieving the handle of a window without giving the full window name vvvv struct results {
I tried installing Java Accesss Bridge for a few hours now. But with no success. The installer from ORACLE does not work (rolls back at the end without error message). Many tries of patching some libs together failed.
What do I need for an application that makes use of JAB. Do I really need some sort of installation or can I simply put some headers and libs together?
I'm a little confused by my programming assignment this week. I've been working at it Wednesday and I've made progress but I'm still confused as to how I'm supposed to do this. The class I made is called Stack, and it's derived from a template class called StackADT. We also utilize a class called unorderedLinkedList, which is derived from a class called linkedList.
We're supposed to implement all of the virtual functions from stackADT in the Stack class. The Stack data is stored in a an unorderedLinkedList, so what I'm confused by is how to implement a few of the Stack functions because there are no functions in unorderedLinkedList which we could call to manipulate the data.
As you can see from my attached code, I'm really confused by how I'm supposed to implement the pop() and top() functions, and I also think my initializeList() function is wrong. We don't have any similar functions in unorderedLinkedList to call, so I'm at a loss of how i'd access my unorderedLinkedList. My initial thought was to call the similar functions in the class that unorderedLinkedList was derived from, linkedList, but I'm unsure of this is what we're supposed to do, or if theres actually a way to access my unorderedLinkedList without having to use the functions from the base class.
NOTE: We're not allowed to modify stackADT, unorderedLinkedList, and linkedList.
Stack.h
#include "stackADT.h" #include "unorderedLinkedList.h" template<class Type> class Stack: public stackADT<Type>{ template <class T> struct nodeType { T info; nodeType<T> *link;
But now I'm trying to use this to point to a function inside a class so instead of do11, i want to be able to point to Basic.Do11. Somehow this doesnt work and I keep on getting this message:
error: argument of type 'void (Basic::)()' does not match 'void (*)()'
so here is a basic program i wrote i am thinking of writing a currency conversion program that does multiple conversions and i was thinking it is possible to do something like this couldnt i call them after i write them as functions
usdtoeuro() usdtokuna()
how would i go about doing that? or can you point me to anything?
I wrote a program which detects a pattern in an array then returns a valve (x) for each time it does. now i tried to call function patt in main so that i can print x but it doesn't let me do it.
#include <stdio.h> int patt(const int SIZE, char str[], int i, int c); int main(void) { const int SIZE=21; char str[SIZE]={'1', '0', '1', '1', '0', '0', '1', '0', '1', '0', '1', '0', '0', '0', '1', '0', '1', '1', '0', '1'}; int i, c=0;
I want to write a function and be able to call it during execution (say during a while(1) loop). Is this possible without having to parse an input string to extract the function and parameters I need or is that the only way?