Android：当我在片段附近使用它时，在runOnUiThread附近收到错误

I am new to Android development and I want to link a button with the animation. I am getting error near runOnUiThread() and getApplication(). When I add this in as an activity it is fine, but when declared in MainFragment it gives error. However when I fix the errors, it creates a method and returns false.

我是Android开发的新手，我想将一个按钮与动画相关联。我在runOnUiThread（）和getApplication（）附近收到错误。当我将它作为一个活动添加时它很好，但是当在MainFragment中声明时它会给出错误。但是，当我修复错误时，它会创建一个方法并返回false。

public class MainFragment extends Fragment {


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

    View rootView = inflater.inflate(R.layout.activity_main, container, false);
    ImageButton btnFacebook = (ImageButton)rootView.findViewById(R.id.facebook2);
    final Animation alpha = AnimationUtils.loadAnimation(getActivity(), R.anim.anim_alpha);

    btnFacebook.setOnClickListener(new Button.OnClickListener(){

        @Override
        public void onClick(View arg0) {
            arg0.startAnimation(alpha);

            Thread thread = new Thread()
            {
                @Override               
                public void run()
                {
                    try
                    {
                        Thread.sleep(1000);
                    }catch(InterruptedException e){                         
                    }
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                          startActivity(new Intent(getApplication(),FacebookActivity.class)); 
                        }

                    });
                }
            };


            thread.start();
          }}); 
    return rootView;
}}

In the XML file I only have the facebook imagebutton. When I click that, it has to trigger the animation and then onclick event has to happen, but I don't know why this error is popping up:

在XML文件中，我只有facebook图像按钮。当我点击它时，它必须触发动画，然后onclick事件必须发生，但我不知道为什么会出现这个错误：

The method runOnUiThread(new Runnable(){}) is undefined for the type new Thread(){}

方法runOnUiThread（new Runnable（）{}）未定义类型new Thread（）{}

And near getapplication() method The method getApplication() is undefined for the type new Runnable(){}

并且接近getapplication（）方法对于new Runnable（）{}类型，未定义getApplication（）方法

If I create the two methods the error goes away, but then when I click onto the button it will not go to the facebookActivity.java file.

如果我创建了两个方法，则错误消失，但是当我单击按钮时，它将不会转到facebookActivity.java文件。

Can anyone tell/help what should I add to solve this issue. Thanks.

任何人都可以告诉/帮助我应该添加什么来解决这个问题。谢谢。

3 个解决方案

#1

runOnUIThread(...) is a method of Activity.

runOnUIThread（...）是Activity的一种方法。

Therefore, use this:

因此，使用此：

getActivity().runOnUIThread(...);

But, beware. You're dealing with asynchronous threads, so your Fragment might be detached from its Activity, resulting in getActivity() returning null. You might want to add a check if(isAdded()) or if(getActivity() != null) before executing.

但是，要小心。您正在处理异步线程，因此您的Fragment可能与其Activity分离，导致getActivity（）返回null。您可能希望在执行之前添加检查if（isAdded（））或if（getActivity（）！= null）。

Alternatively, use an AsyncTask, which handles this running on the ui thread by itself.

或者，使用AsyncTask，它自己处理在ui线程上运行的这个。

#2

runOnUiThread(new Runnable(){}) is method in Activity not in the Fragment.

so you need to change

所以你需要改变

runOnUiThread(new Runnable(){})

into

成

getActivity().runOnUiThread(new Runnable(){})

For your requrement it is better to use Handler instead of Thread for waiting 1000 milli seconds..

对于您的要求，最好使用Handler而不是Thread来等待1000毫秒..

#3

Please use getActivity() instead of using getApplication() .

请使用getActivity（）而不是使用getApplication（）。

which returns the activity associated with a fragment. The activity is a context.

返回与片段关联的活动。活动是一个背景。

#1