Question

当我尝试MainActivity is not an enclosing class扩展Fragment类中的Webview时出现错误addJavascriptInterface：

mXWalkView.addJavascriptInterface(new MainActivity.JS_Bind(this, mXWalkView),"Android");

在我的MainActivity中，我在onCreate方法中以这种方式实现了它：

mXWalkView.addJavascriptInterface(new JS_Bind(this, mXWalkView),"Android");

JS_Bind是MainActivity中的公共类：

public class JS_Bind {
    private static final String TAG = "JS_Bind";
    private Context context;
    private XWalkView mXWalkView;

    public JS_Bind(Context c, XWalkView mXWalkView) {
        context = c;
        this.mXWalkView = mXWalkView;
    }

    @org.xwalk.core.JavascriptInterface
    public void makeToast(String toast) {
        Toast mToast = Toast.makeText(context, toast, Toast.LENGTH_SHORT);
        mToast.setGravity(Gravity.CENTER, 0, 0);
        mToast.show();
    }
}

注意：我还使用Crosswalk（Webview库）。如何修复此错误以及它究竟是什么意思？我读了类似的问题和答案，但没有理解。

修改：Fragment课程：

public class SlideFragment extends Fragment {
    private XWalkView mXWalkView;
    private Context c;

    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_demo, container, false);

    }

   @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        int position = FragmentPagerItem.getPosition(getArguments());

        XWalkPreferences.setValue(XWalkPreferences.REMOTE_DEBUGGING, true);
        mXWalkView.addJavascriptInterface(new MainActivity.JS_Bind(this, mXWalkView),"Android");
        mXWalkView = (XWalkView) view.findViewById (R.id.webView);
        mXWalkView.clearCache(true);

        mXWalkView.load(MainActivity.ROOT + "?s=" + getArguments().getString("title") + ".php?page=" + position, null);

Answer 1

Fragment无法将this用作Context，因为Fragment不会延伸Context。在调用JS_Bind的构造函数时，请使用getActivity()或getContext()。

修改

mXWalkView.addJavascriptInterface(new MainActivity.JS_Bind(getActivity(),
        mXWalkView), "Android");

扩展片段：添加JavacriptInterface时，MainActivity不是封闭类

1 个答案: