return 对使用 onCreate 的响应以及为什么入队不是异步完成的

Question

在将它发送到我的 XMLPullParserHandler 之后是否可以 return peepWithPics，以便我可以调用它 onCreate 并将其设置为 listView 适配器。我不确定如何将它传递给我们的任何其他方法或 class。调用 listViewAdapter 在这种方法中工作，但我无法让 setOnItemClickLIstener 工作，所以想如果我可以在 onCreate 中创建适配器，然后在 setOnItemCLickLister 中创建，应该可以帮助我继续我的开发。

我还读到使用 OkHttp3 进行调用是异步进行的，但我收到错误。

android.view.ViewRootImpl$CalledFromWrongThreadException：只有创建视图层次结构的原始线程才能接触其视图。此错误位于代码行

listView.setAdapter(adapter);

整个方法如

public void getXMLData() {
        OkHttpClient client = getUnsafeOkHttpClient();
        Request request = new Request.Builder()
                .url(myURL)
                .build();
        client.newCall(request).enqueue(new Callback() {
            //    android.os.Handler mainHanlder = new android.os.Handler(context.getMainLooper());

            @Override
            public void onFailure(Call call, IOException e) {
                e.printStackTrace();
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                final String responseData = response.body().string();
                final InputStream stream = new ByteArrayInputStream(responseData.getBytes());

                /*mainHanlder.post(new Runnable() {

                    @Override
                    public void run() {*/
                ArrayList<PeepWithPic> peepWithPics;
                XMLPullParserHandler parserHandler = new XMLPullParserHandler();
                peepWithPics = (ArrayList<PeepWithPic>) parserHandler.parse(stream);
                        /*ListViewAdapter adapter = new ListViewAdapter(getApplicationContext(), peepWithPics);
                        listView.setAdapter(adapter);
                        listView.setVisibility(View.VISIBLE);
                        mProgressBar.setVisibility(View.GONE);*/
                    /*}
                });*/
            }
        });
    }

我试过在 mProgressBar 设置为 gone 后添加。

listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                                    @Override
                                    public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                                        Toast.makeText(getApplicationContext(), "WORKS FROM RUNONUI", Toast.LENGTH_LONG).show();
                                    }

我也在 onCreate 方法中尝试了相同的 setOnItemClickListener

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        context = getApplicationContext();
        listView = (ListView) findViewById(R.id.contactListView);
        mProgressBar = (ProgressBar) findViewById(R.id.progressBar);
        mProgressBar.setVisibility(View.VISIBLE);
        getXMLData();
    }

在onCreate中调用了getXMLData方法

Answer 1

解决方案应该像使用 Activity 的 runOnUiThread(Runnable) 方法一样简单，我也会创建适配器并在调用 getXMLData() 之前设置它：

将这些添加为您的 Activity

的成员变量

List<PeepWithPic> mPeepWithPics = new ArrayList<PeepWithPic>(); 
ListViewAdapter mAdapter;

然后在 onCreate() 中初始化您的 Adapter:

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        context = getApplicationContext();
        listView = (ListView) findViewById(R.id.contactListView);
        mProgressBar = (ProgressBar) findViewById(R.id.progressBar);
        mProgressBar.setVisibility(View.VISIBLE);
        mAdapter = new ListViewAdapter(this, mPeepWithPics);
        listView.setAdapter(mAdapter);
        /* THIS DOES NOT WORK WHEN YOU HAVE A CLICKABLE VIEW IN A CUSTOM ADAPTER
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener(){
             @Override
             public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                 Toast.makeText(getApplicationContext(), "WORKS FROM RUNONUI", Toast.LENGTH_LONG).show();
             }
        }); */
        getXMLData();
    }

然后将您的方法更改为：

public void getXMLData() {
    OkHttpClient client = getUnsafeOkHttpClient();
    Request request = new Request.Builder()
            .url(myURL)
            .build();
    client.newCall(request).enqueue(new Callback() {

        @Override
        public void onFailure(Call call, IOException e) {
            e.printStackTrace();
        }

        @Override
        public void onResponse(Call call, Response response) throws IOException {
            final String responseData = response.body().string();
            final InputStream stream = new ByteArrayInputStream(responseData.getBytes());
            XMLPullParserHandler parserHandler = new XMLPullParserHandler();
            final ArrayList<PeepWithPic> peepWithPics = (ArrayList<PeepWithPic>) parserHandler.parse(stream);
            mPeepWithPics.clear();
            mPeepWithPics.addAll(peepWithPics);

            /* Now tell the adapter on the UI thread its data changed*/
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                   mAdapter.notifyDataSetChanged();
                   listView.setVisibility(View.VISIBLE);
                   mProgressBar.setVisibility(View.GONE);
                }
            });
        }
    });
}

更新

为了处理点击，您必须在根布局的 Adpater 中添加一个 OnItemClickListener，因为您的适配器是自定义的并且视图包含可点击的小部件。

祝你好运，编码愉快！

return 对使用 onCreate 的响应以及为什么入队不是异步完成的

return response to use onCreate and why is enqueue not done asynchronously

android

listview

asynchronous

okhttp3