Xamarin.Android Binding Library

Question

Xamarin.Android Binding Library

nnovalbos 371

Hi,

I am trying to use a native Android library in Xamarin.forms

I'm having compilation issues that I haven't been able to fix by editing the Metadata.xml

The problem comes in that the native library has an abstract class A, another abstract class B that inherits from A and a class C that inherits from B

Class A has an abstract method: public abstract byte [] flush ()

Class B inherits it but does not implement it: public abstract byte [] flush []

Class C already implements the method.

The issue is that the compilation result is wrong, the C # conversion of class B does not add the 'override' to the flush method.

To solve this, I added in the file "metadata.xml" an 'att' that modifies the visibility to the flush method:

<att path = ".. package ../ class ../ method" name = "visibility"> public override </att>

This fixes this problem but duplicates the word 'override' in one place.

The compilation of the library generates the class 'B' in C #, which has the flush method, to which 'override' has been added and it is correct. But the compilation has also generated a class 'BInvoker', which inherits from B and in this case that flush method already had the override, so it duplicates it and gives a compilation error: "duplicate override"

Is there a way to work around this in the Metadata or EnumMethods.xml? Currently for it to compile I have to remove the 'override' manually.

Thanks a lot

JarvanZhang 23,971 Reputation points

2021-03-08T06:50:00.65+00:00
The issue is that the compilation result is wrong, the C # conversion of class B does not add the 'override' to the flush metho

Hi, nnovalbos-6961. Is the Class B like below? In this case, ‘TestMethod’ is not inherited from Class A.

public abstract class TestClassB extends TestClassA { public abstract void TestMethod(); }

If you want to make the ClassB to override the method, try changing the code as below.

public abstract class TestClassB extends TestClassA { @Override public void TestMethod() { } }
nnovalbos 371 Reputation points

2021-03-08T07:55:47.757+00:00
Hi @JarvanZhang ,

Thanks for answering

Yes, so comes class B.

public abstract class TestClassB extends TestClassA { public abstract void TestMethod(); }

I obtained that code by decompiling the jar 'classes.jar' that was inside the .aar, so I cannot change that third-party java code. I understand that if it is compiled and packaged it will work ...

My idea is to know if there is any option to edit the metadata.xml or the EnumMethods.xml to solve the problem that I exposed, since the .aar I cannot modify it.
JarvanZhang 23,971 Reputation points

2021-03-09T09:56:56.933+00:00

the C # conversion of class B does not add the 'override' to the flush method

Because class B doesn't override the class A in native library. Is there any error occur when compiling the project.

Your answer

JarvanZhang 23,971 Reputation points

2021-03-08T06:50:00.65+00:00

The issue is that the compilation result is wrong, the C # conversion of class B does not add the 'override' to the flush metho

Hi, nnovalbos-6961. Is the Class B like below? In this case, ‘TestMethod’ is not inherited from Class A.

public abstract class TestClassB extends TestClassA { public abstract void TestMethod(); }

If you want to make the ClassB to override the method, try changing the code as below.

public abstract class TestClassB extends TestClassA { @Override public void TestMethod() { } }
nnovalbos 371 Reputation points

2021-03-08T07:55:47.757+00:00

Hi @JarvanZhang ,

Thanks for answering

Yes, so comes class B.

public abstract class TestClassB extends TestClassA { public abstract void TestMethod(); }

I obtained that code by decompiling the jar 'classes.jar' that was inside the .aar, so I cannot change that third-party java code. I understand that if it is compiled and packaged it will work ...

My idea is to know if there is any option to edit the metadata.xml or the EnumMethods.xml to solve the problem that I exposed, since the .aar I cannot modify it.
JarvanZhang 23,971 Reputation points

2021-03-09T09:56:56.933+00:00

the C # conversion of class B does not add the 'override' to the flush method

Because class B doesn't override the class A in native library. Is there any error occur when compiling the project.

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Xamarin.Android Binding Library

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