将浮点数组从Java返回到jni

Question

I'm calling a java method from jni.This method return a float[]

   jclass javaClass = env->GetObjectClass(activityObj);
   jmethodID method = env->GetMethodID(javaClass,"findparam", "([FF)F");
   jfloatArray rotateArray = env->CallFloatMethod(activityObj, method, s1, s2);

But when i tried to compile it i had :

   error: cannot convert 'jfloat' to '_jfloatArray*' in initialization

how can i get the returnet float array??

Answer 1

Just try to use jfloatArray imageArray = (jfloatArray) env->CallObjectMethod(Object,method); It should resolve your problem .

Answer 2

All array types (even primitive types) are returned as a jobject which you should then cast to the appropriate j<type>Array type.

So your final line should read:

jfloatArray rotateArray = (jfloatArray)env->CallObjectMethod(activityObj, method, s1, s2);

Answer 3

CallFloatMethod() is for calling methods that return float . You are calling a method that returns float[] . You should be calling CallObjectMethod() .