无法填充微调器

Question

我想填充一个位于Dialog中的微调器，但无法使上下文起作用。换句话说，我无法在ArrayAdapter中获得正确的上下文

这是代码

             fab2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //Create Add Bookamrk Dialog
            AlertDialog.Builder mBuilder = new AlertDialog.Builder(MainActivity.this);
            View cView = getLayoutInflater().inflate(R.layout.dialog_addbookmark, null);
            final EditText dTitle = (EditText) 
            //Declare all Textboxes, button and SPINNER
            //Populate spinner
            List<String> spinnerArray =  new ArrayList<String>();
            for (Category c: myCategories) {
                spinnerArray.add(c.getName());
            }
            // I GET THE ERROR HERE ON THE CONTEXT
            ArrayAdapter<String> adapter = new ArrayAdapter<String>(mBuilder.getContext(), android.R.layout.simple_spinner_dropdown_item, spinnerArray);
            adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            sItems.setAdapter(adapter);

            //Create Click
            cCreate.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    if (!dTitle.getText().toString().isEmpty() || !dURL.getText().toString().isEmpty() || !dCategory.getText().toString().isEmpty()) {
                        addBookmark(dTitle.getText().toString(), dURL.getText().toString(), dCategory.getText().toString());
                    } else {
                        Toast.makeText(MainActivity.this, "Please fill the Name", Toast.LENGTH_SHORT).show();
                    }
                }
            });
            mBuilder.setView(cView);
            AlertDialog dialog = mBuilder.create();
            dialog.show();
        }
    });

该对话框是通过按一个按钮创建的，届时我希望填充微调器