This situation I took a working code that uses C files and added to my project.

And when I need to use a method, I get this error

 No implementation found for boolean ucrop.task.BitmapCropTask.cropCImg

Although I changed all the ways to my own, this method still does not see.

What could be the problem?

Here is my method

 @SuppressWarnings("JniMissingFunction") native public static boolean cropCImg(// String inputPath,// String outputPath,// int left, // int top, // int width, // int height, // float angle, // float resizeScale, // int format, // int quality, // int exifDegrees,// int exifTranslation// ) throws IOException, OutOfMemoryError;

And here is its implementation

 #include <stdio.h> #include <jni.h> #include <vector> #include <android/log.h> #include "ucrop_task_BitmapCropTask.h" using namespace std; #define cimg_display 0 #define cimg_use_jpeg #define cimg_use_png #define cimg_use_openmp #include "CImg.h" using namespace cimg_library; #define LOG_TAG "uCrop JNI" #define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__) #define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__) #define SAVE_FORMAT_JPEG 0 #define SAVE_FORMAT_PNG 1 JNIEXPORT jboolean JNICALL Java_ucrop_task_BitmapCropTask_cropCImg (JNIEnv *env, jobject obj, jstring pathSource, jstring pathResult, jint left, jint top, jint width, jint height, jfloat angle, jfloat resizeScale, jint format, jint quality, jint exifDegrees, jint exifTranslation) { LOGD("Crop image with CImg"); const char *file_source_path = env->GetStringUTFChars(pathSource, 0); const char *file_result_path = env->GetStringUTFChars(pathResult, 0); try { CImg<unsigned char> img(file_source_path); const int x0 = left, y0 = top, x1 = left + width - 1, y1 = top + height - 1; /* LOGD("left %d\ntop: %d", left, top); LOGD("width %d\nheight: %d", width, height); LOGD("angle %f\nresizeScale: %f", angle, resizeScale); LOGD("image size pre: %dx %d", img.width(), img.height()); LOGD("exifDegrees: %d \nexifTranslation: %d", exifDegrees, exifTranslation); */ // Handle exif. However it is slow, maybe calculate warp field according to exif rotation/translation. if (exifDegrees != 0) { img.rotate(exifDegrees); } if (exifTranslation != 1) { img.mirror("x"); } const int size_x = img.width() * resizeScale, size_y = img.height() * resizeScale, size_z = -100, size_c = -100, interpolation_type = 1; const unsigned int boundary_conditions = 0; const float centering_x = 0, centering_y = 0, centering_z = 0, centering_c = 0; if (resizeScale != 1) { img.resize(size_x, size_y, size_z, size_c, interpolation_type, boundary_conditions, centering_x, centering_y, centering_z, centering_c); } // Create warp field. CImg<float> warp(cimg::abs(x1 - x0 + 1), cimg::abs(y1 - y0 + 1), 1, 2); const float rad = angle * cimg::PI/180, ca = std::cos(rad), sa = std::sin(rad), ux = cimg::abs(img.width() * ca), uy = cimg::abs(img.width() * sa), vx = cimg::abs(img.height() * sa), vy = cimg::abs(img.height() * ca), w2 = 0.5f * img.width(), h2 = 0.5f * img.height(), dw2 = 0.5f * (ux + vx), dh2 = 0.5f * (uy + vy); cimg_forXY(warp, x, y) { const float u = x + x0 - dw2, v = y + y0 - dh2; warp(x, y, 0) = w2 + u*ca + v*sa; warp(x, y, 1) = h2 - u*sa + v*ca; } img = img.get_warp(warp, 0, 1, 2); if (format == SAVE_FORMAT_JPEG) { img.save_jpeg(file_result_path, quality); } else if (format == SAVE_FORMAT_PNG) { img.save_png(file_result_path, 0); } else { img.save(file_result_path); } ~img; env->ReleaseStringUTFChars(pathSource, file_source_path); env->ReleaseStringUTFChars(pathResult, file_result_path); return true; } catch (CImgInstanceException e) { env->ThrowNew(env->FindClass("java/lang/OutOfMemoryError"), e.what()); } catch (CImgIOException e) { env->ThrowNew(env->FindClass("java/io/IOException"), e.what()); } return false; }

Here it is added to your grad

 sourceSets.main { jni.srcDirs = [] }

Why can not see this method? If you need to add something say

    0