java如何从函数中添加片段？

Question

我想在屏幕上创建背景片段，用于加载查询

它不工作，我在屏幕上看不到碎片

public class internet {
    startQueryAsync(final Activity activity) {

       new Thread() {

            RelativeLayout backView = new RelativeLayout(activity);

            @Override
            public void run() {
                activity.runOnUiThread(new Runnable() {
                    @Override
                    public void run() {

                        FragmentLoad fr = new FragmentLoad();
                        activity.getFragmentManager().beginTransaction().add(安卓.R.id.content, fr);
                    }
                });
            }
        }.start();
   }
}


public class FragmentLoad extends Fragment {

    public FragmentLoad() {
        super();
    }

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

       View view = inflater.inflate(R.layout.fragment_load, container);
       view.setLayoutParams(lpFr);

       return view;
    }
}

我不明白为什么它不起作用

Answer 1

您尚未提交您的碎片事务。像这样改变你的方法

public void run() {
    FragmentLoad fr = new FragmentLoad();
    activity.getFragmentManager().beginTransaction().add(android.R.id.content, fr).commit(); // change this
}

Answer 2

你忘了做fragment的commit();

例如：

activity.runOnUiThread(new Runnable() {
    @Override
    public void run() {
        // First, create your FragmentManager.
        FragmentManager manager = activity.getFragmentManager();

        // Then, create your transaction.
        FragmentTransaction transaction = manager.beginTransaction();

        // Add your fragment in the view.
        transaction.add(android.R.id.content, new FragmentLoad());

        // Commit the transaction.
        transaction.commit();
    }
});

您也可以使用Fluent Interface Pattern来执行以下操作：

activity.getFragmentManager()
    .beginTransaction()
    .add(android.R.id.content, new FragmentLoad())
    .commit();

有关更多详细信息，请参阅Google Fragment Documentation

希望这有帮助