片段可以从其父活动中实现两个接口吗？答案

【问题标题】：Can a fragment implement two interfaces from its parent activity?片段可以从其父活动中实现两个接口吗？
【发布时间】：2014-07-21 03:38:52
【问题描述】：

为了在 Fragment 之间进行通信，我们使用父 Activity 实现的接口模式...就像在文档中一样，例如 Fragment 可以在其附加到 Activity 时获取父接口。

public class HeadlinesFragment extends ListFragment {
    OnHeadlineSelectedListener mCallback;

    // Container Activity must implement this interface
    public interface OnHeadlineSelectedListener {
        public void onArticleSelected(int position);
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);

        // This makes sure that the container activity has implemented
        // the callback interface. If not, it throws an exception
        try {
            mCallback = (OnHeadlineSelectedListener) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString()
                    + " must implement OnHeadlineSelectedListener");
        }
    }

...
}

但是比如说父 Activity 实现了另一个接口

public interface OnThreadCliked{
    void onThreadClicked(Post post);
}

有没有办法获得对活动实现的第二个接口的引用？

【问题讨论】：

标签： android android-fragments interface

【解决方案1】：

当然，只需施放两次：

OnThreadCliked mCallback2;

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);

    // This makes sure that the container activity has implemented
    // the callback interface. If not, it throws an exception
    try {
        mCallback = (OnHeadlineSelectedListener) activity;
    } catch (ClassCastException e) {
        throw new ClassCastException(activity.toString()
                + " must implement OnHeadlineSelectedListener");
    }

    // This makes sure that the container activity has implemented
    // the second callback interface. If not, it throws an exception
    try {
        mCallback2 = (OnThreadCliked) activity;
    } catch (ClassCastException e) {
        throw new ClassCastException(activity.toString()
                + " must implement OnThreadCliked");
    }
}

【讨论】：