extern "C" int add(int* a，int* b，int* c，int d，char* PicPath)
{
FILE * fp
fp=fopen(PicPath，" wt ")；
for(int I = 0； I
{
c[I]= a[I]+b[I]；
fprintf(fp，" %d\n "，c[I])；
}
fclose(FP)；
Returns1;
}
The function of this function is to add the values of two arrays A and B, and in the stored array C, write and into the specified file, the dimension of the array.
A parameter was passed in.
Questions raised:
How to call the parameter of pointer type in 1.Java;
2. Can plastic parameters be transmitted directly? ;
3. Why 3? PicPath pointer type and why not CString type?
4. How to get the return value of input parameters;
The code of Java calling dynamic link library is as follows:
JNative t= new JNative("test.dll "，" add ")； //Load the test.dll file and call the add method;
T.setRetVal (type. INT)； //Set the return type after calling.
//Use Java to construct pointers and allocate space for pointers.
Pointer a = new pointer (memoryblockfactory.creatememoryblock (4 *10));
Pointer b = new pointer (memoryblockfactory.creatememoryblock (4 *10));
Pointer c = new pointer (memoryblockfactory.creatememoryblock (4 *10));
Strp = createpointer (100);
strP.setStringAt(0，" C:\ \ 1 . txt))；
int d = 10；
//assign values to arrays a and B.
for(int I = 0； I
a.setIntAt(4 * i，I)；
b.setIntAt(4 * i，I)；
}
//Set parameters:
t.setParameter(0，a)；
t.setParameter( 1，b)；
t.setParameter(2，c)；
t.setParameter(3，d)；
t.setParameter(4，strP)；
t . invoke()； //Call the function and execute it
//output the value of sum. Note: an integer value needs to store 4 bytes, so j needs to be multiplied by 4.
for(int j = 0； j
system . out . println(c . getas int(4 * j))；
}
//Free memory
a . dispose()；
b . dispose()；
c . dispose()；
Well, such a complete calling example is over. I just wrote the key code in the program, and I need to write another one.
Class, and inherit a base class, in the method of copying the base class, these are relatively simple, you can refer to other online.
Examples.
Answer to the question:
Call the pointer type parameter in 1. Java: You need to create a pointer variable and allocate space for it.
2. The shaped data can be directly transmitted;
3. jnnative doesn't support CString type very well. When calling the CString method, some exceptions are often reported, so I changed the path to.
Character pointer of;
4. Input parameters as output: You can see the above example, how the array C is set and output.