Java 在Android中同时扩展片段和活动

我在Android Studio中使用幻灯片视图时遇到问题。 我不能让我的按钮工作，我不知道如何在同一个类中扩展

片段

和

活动

。请看一看，您是否可以帮助我：

public class tab1 extends Fragment {


    private static int RESULT_LOAD_IMG = 1;
    String imgDecodableString;


    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

        if (container == null) {
            return null;
        }

        View view=inflater.inflate(R.layout.tab1,container,false);
        return view;


    }



class tab1f extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.tab1);
    }


    @Override
    protected void onStart() {
        super.onStart();

        Button upload = (Button) findViewById(R.id.upload);

        upload.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {
                // Create intent to Open Image applications like Gallery, Google Photos
                Intent galleryIntent = new Intent(Intent.ACTION_PICK,
                        android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                // Start the Intent
                startActivityForResult(galleryIntent, RESULT_LOAD_IMG);


            }


        });


    }

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        try {
            // When an Image is picked
            if (requestCode == RESULT_LOAD_IMG && resultCode == RESULT_OK
                    && null != data) {
                // Get the Image from data

                Uri selectedImage = data.getData();
                String[] filePathColumn = {MediaStore.Images.Media.DATA};

                // Get the cursor
                Cursor cursor = getContentResolver().query(selectedImage,
                        filePathColumn, null, null, null);
                // Move to first row
                cursor.moveToFirst();

                int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
                imgDecodableString = cursor.getString(columnIndex);
                cursor.close();
                ImageView imgView = (ImageView) findViewById(R.id.imgView);
                // Set the Image in ImageView after decoding the String
                imgView.setImageBitmap(BitmapFactory
                        .decodeFile(imgDecodableString));

            } else {
                Toast.makeText(this, "You haven't picked Image",
                        Toast.LENGTH_LONG).show();
            }
        } catch (Exception e) {
            Toast.makeText(this, "Something went wrong", Toast.LENGTH_LONG)
                    .show();
        }

    }


}


}

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java不支持多重继承。这意味着两个父类不能有一个子类

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我不是很确定，但请检查Fragment类是否有类似的接口。然后您可以将其用于类扩展活动

我不知道如何在同一个类中扩展片段和活动-您不能在Java中扩展多个类。您提交的代码示例应该在3到8行代码之间，而不是100行。Stackoverflow要求新用户发布代码，但这样发布整个程序是对该要求意图的嘲弄。