错误信息
java.lang.NullPointerException: Attempt to invoke virtual method 'void org.opencv.objdetect.CascadeClassifier.detectMultiScale(org.opencv.core.Mat, org.opencv.core.MatOfRect, double, int, int, org.opencv.core.Size, org.opencv.core.Size)' on a null object reference
at com.example.myapplication.MainActivity.procSrc2Gray(MainActivity.java:139)
at com.example.myapplication.MainActivity$ProcessClickListener.onClick(MainActivity.java:188)
at android.view.View.performClick(View.java:4780)
at android.view.View$PerformClick.run(View.java:19866)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
说是空指针但是找不到问题在哪里。。
求好心人帮帮我。。
前面我有给分类器赋值
public void initializeOpenCVDependencies() {
try {
// Copy the resource into a temp file so OpenCV can load it
InputStream is = getResources().openRawResource(R.raw.cars);
File cascadeDir = getDir("cars", Context.MODE_PRIVATE);
File mCascadeFile = new File(cascadeDir.getAbsoluteFile(), "cars.xml");
FileOutputStream os = new FileOutputStream(mCascadeFile);
byte[] buffer = new byte[4096];
int bytesRead=0;
while ((bytesRead = is.read(buffer)) != -1) {
os.write(buffer, 0, bytesRead);
}
is.close();
os.close();
// Load the cascade classifier
detectface = new CascadeClassifier(mCascadeFile.getAbsolutePath());
} catch (Exception e) {
Log.e("OpenCVActivity", "Error loading cascade", e);
}
}
```请问是不是赋值语句有问题？
