0

当我在 Android Studio 中运行我的应用程序时，一切都运行正常。通过运行 RushSearch() 查询正确填充抽屉中的 ListView。但是，当我创建了 apk 并在智能手机上安装以尝试运行该应用程序时，第一次运行时 Drawer 中的 ListView 没有填充。如果我关闭应用程序并再次运行它，一切都是正确的。

为什么会出现这种异常？

MainActivity.java 类的 onCreate 方法的代码是这样的

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    callWebservice();

    // Layout principale col drawer
    setContentView(R.layout.activity_main_drawer);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    leftArrow = (ImageView) findViewById(R.id.left_arrow);
    titolo = (TextView) findViewById(R.id.titolo_id);

    ActionBarDrawerToggle actionBarDrawerToggle =
            new ActionBarDrawerToggle(this, drawerLayout, toolbar,
                    R.string.navigation_drawer_open, R.string.navigation_drawer_close);

    drawerLayout.setDrawerListener(actionBarDrawerToggle);
    actionBarDrawerToggle.syncState();

    drawerListView = (ListView) findViewById(R.id.drawer_listView);

    // SELECT * FROM Sections where Fk == 0;
    sectionsList = new RushSearch().whereEqual("Fk", 0).find(Sections.class);
    Log.d("ELEMENTI",""+sectionsList.size());
    drawerListViewAdapter = new DrawerListViewAdapter(sectionsList, getApplicationContext());

    // Adapter che si occupa di popolare il drawer
    drawerListView.setAdapter(drawerListViewAdapter);


    // Listner per il click su un elemento del drawer
    drawerListView.setOnItemClickListener(click);
}

callWebservice() 方法负责从 url 获取 JSON 文件，其代码如下

private void callWebservice() {

    String tag_json_obj = "GetItem";
    String url = String.format("http://digitalbox.getsandbox.com/item");
    JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {

            try {
                saveSections(response.getJSONArray("Sections"));

            } catch (JSONException e) {
                e.printStackTrace();
            }

        }
    }, new Response.ErrorListener() {
        public void onErrorResponse(VolleyError error) {
            VolleyLog.d("Settings", "Error: " + error.getMessage());
        }
    }) {
        @Override
        public Map<String, String> getHeaders() throws AuthFailureError {
            HashMap<String, String> headers = new HashMap<String, String>();
            headers.put("Content-Type", "application/json");
            headers.put("Accept", "application/json");
            return headers;
        }
    };
    NetworkController.getInstance().addToRequestQueue(jsonObjectRequest, tag_json_obj);
}

private void saveSections(final JSONArray section) {

    Thread t = new Thread(new Runnable() {
        @Override
        public void run() {


            int c = section.length();
            for (int i = 0; i < c; i++) {

                try {
                    JSONObject obj = section.getJSONObject(i);

                    Sections s = new RushSearch().whereEqual("ID", obj.getInt("ID")).findSingle(Sections.class);
                    if (s == null) {
                        s = new Sections();
                        s.setID(obj.getInt("ID"));
                    }

                    if (!obj.isNull("Fk"))
                        s.setFk(obj.getInt("Fk"));

                    s.setTitle(obj.getString("Title"));

                    if (!obj.isNull("CategoryColor"))
                        s.setCategoryColor(obj.getString("CategoryColor"));

                    s.setPos(obj.getInt("Pos"));
                    s.setLanguageId(obj.getInt("LanguageId"));
                    s.setUnavailableForSend(obj.getBoolean("UnavailableForSend"));

                    s.save();

                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }

            Log.d("sections", "DB updated");


        }
    });
    t.setPriority(Thread.MIN_PRIORITY);
    t.start();
}

如果我在 AVD 智能手机中使用 Android Studio 运行应用程序，我有这个日志

    11-30 15:21:53.520 2170-2170/? I/art: Not late-enabling -Xcheck:jni (already on)
11-30 15:21:53.520 2170-2170/? I/art: Late-enabling JIT
11-30 15:21:53.558 2170-2170/? I/art: JIT created with code_cache_capacity=2MB compile_threshold=1000
11-30 15:21:53.685 2170-2170/rawpepper.it.digitalbox W/System: ClassLoader referenced unknown path: /data/app/rawpepper.it.digitalbox-2/lib/x86
11-30 15:21:54.099 2170-2170/rawpepper.it.digitalbox W/art: Before Android 4.1, method int android.support.v7.internal.widget.ListViewCompat.lookForSelectablePosition(int, boolean) would have incorrectly overridden the package-private method in android.widget.ListView
11-30 15:21:54.469 2170-2170/rawpepper.it.digitalbox D/ELEMENT: 13
11-30 15:21:54.486 2170-2210/rawpepper.it.digitalbox D/OpenGLRenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: true
11-30 15:21:54.592 2170-2210/rawpepper.it.digitalbox I/OpenGLRenderer: Initialized EGL, version 1.4
11-30 15:21:54.719 2170-2210/rawpepper.it.digitalbox W/EGL_emulation: eglSurfaceAttrib not implemented
11-30 15:21:54.719 2170-2210/rawpepper.it.digitalbox W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0xad6fc2e0, error=EGL_SUCCESS
11-30 15:21:57.542 2170-2204/rawpepper.it.digitalbox D/Volley: [117] BasicNetwork.logSlowRequests: HTTP response for request=<[ ] http://digitalbox.getsandbox.com/item 0x95b78f5f NORMAL 1> [lifetime=3034], [size=196862], [rc=200], [retryCount=0]
11-30 15:21:57.691 2170-2180/rawpepper.it.digitalbox W/art: Suspending all threads took: 25.964ms
11-30 15:21:57.909 2170-2405/rawpepper.it.digitalbox D/sections: DB updated

这告诉我 sectionList 数组中的元素数是 13（第六行），这是正确的。 使用 Android Studio 运行应用程序

    11-30 15:35:01.765 17183-17183/rawpepper.it.digitalbox I/art: Late-enabling -Xcheck:jni
11-30 15:35:01.883 17183-17183/rawpepper.it.digitalbox W/System: ClassLoader referenced unknown path: /data/app/rawpepper.it.digitalbox-2/lib/arm
11-30 15:35:02.357 17183-17183/rawpepper.it.digitalbox W/art: Before Android 4.1, method int android.support.v7.internal.widget.ListViewCompat.lookForSelectablePosition(int, boolean) would have incorrectly overridden the package-private method in android.widget.ListView
11-30 15:35:03.235 17183-17183/rawpepper.it.digitalbox D/ELEMENT: 0
11-30 15:35:03.249 17183-17260/rawpepper.it.digitalbox D/OpenGLRenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: true
11-30 15:35:03.304 17183-17260/rawpepper.it.digitalbox I/Adreno-EGL: <qeglDrvAPI_eglInitialize:379>: QUALCOMM Build: 09/02/15, 76f806e, Ibddc658e36
11-30 15:35:03.306 17183-17260/rawpepper.it.digitalbox I/OpenGLRenderer: Initialized EGL, version 1.4
11-30 15:35:05.976 17183-17321/rawpepper.it.digitalbox D/sections: DB updated

这告诉我 sectionList 数组中的元素为 0，但如果我关闭并再次运行它，一切都是正确的。

4

4 回答 4

0

下载数据后，您需要设置抽屉。例如，在下载新部分时调用 saveDate() 并在 onCreate() 中调用 setUpDraw()。 

private void saveData(Sections newSections) {
    newSections.save()
    setUpDraw()
}

private void setUpDraw() {

    drawerListView = (ListView) findViewById(R.id.drawer_listView);
    sectionsList = new RushSearch().whereEqual("Fk", 0).find(Sections.class);
    drawerListViewAdapter = new DrawerListViewAdapter(sectionsList, context); // You don't want application context
    drawerListView.setAdapter(drawerListViewAdapter);
    drawerListView.setOnItemClickListener(click);
}
于 2015-11-30T21:50:04.120 回答
0

没问题。尝试这个：

private void callWebservice() {
    String tag_json_obj = "GetItem";
    String url = String.format("http://digitalbox.getsandbox.com/item");
    JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {

            try {
                new SaveData().execute(response.getJSONArray("Sections"));
            } catch (JSONException e) {
                e.printStackTrace();
            }

        }
    }, new Response.ErrorListener() {
        public void onErrorResponse(VolleyError error) {
            VolleyLog.d("Settings", "Error: " + error.getMessage());
        }
    }) {
        @Override
        public Map<String, String> getHeaders() throws AuthFailureError {
            HashMap<String, String> headers = new HashMap<String, String>();
            headers.put("Content-Type", "application/json");
            headers.put("Accept", "application/json");
            return headers;
        }
    };
    NetworkController.getInstance().addToRequestQueue(jsonObjectRequest, tag_json_obj);
}

然后在你的活动中添加这个内部类：

private final class SaveData extends AsyncTask<JSONArray, Void, Void> {
    protected Void doInBackground(JSONArray... params) {
        int c = section.length();
        for (int i = 0; i < c; i++) {

            try {
                JSONObject obj = section.getJSONObject(i);

                Sections s = new RushSearch().whereEqual("ID", obj.getInt("ID")).findSingle(Sections.class);
                if (s == null) {
                    s = new Sections();
                    s.setID(obj.getInt("ID"));
                }

                if (!obj.isNull("Fk"))
                    s.setFk(obj.getInt("Fk"));

                s.setTitle(obj.getString("Title"));

                if (!obj.isNull("CategoryColor"))
                    s.setCategoryColor(obj.getString("CategoryColor"));

                s.setPos(obj.getInt("Pos"));
                s.setLanguageId(obj.getInt("LanguageId"));
                s.setUnavailableForSend(obj.getBoolean("UnavailableForSend"));

                s.save();

            } catch (JSONException e) {
                e.printStackTrace();
            }
        }

        Log.d("sections", "DB updated");
        return null;
    }

    public void onPostExecute(Void result) {
        sectionsList = new RushSearch().whereEqual("Fk", 0).find(Sections.class);
        Log.d("ELEMENTI",""+sectionsList.size());
        drawerListViewAdapter = new DrawerListViewAdapter(sectionsList, getApplicationContext());
    }
}

我希望这有帮助！

于 2015-12-01T15:39:44.513 回答
0

我已经修改了我的代码，现在我有了这个onCreate()方法的代码

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        callWebservice();

//        setContentView(R.layout.activity_main);

        // Layout principale col drawer
        setContentView(R.layout.activity_main_drawer);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        leftArrow = (ImageView) findViewById(R.id.left_arrow);
        titolo = (TextView) findViewById(R.id.titolo_id);

        ActionBarDrawerToggle actionBarDrawerToggle =
                new ActionBarDrawerToggle(this, drawerLayout, toolbar,
                        R.string.navigation_drawer_open, R.string.navigation_drawer_close);

        drawerLayout.setDrawerListener(actionBarDrawerToggle);
        actionBarDrawerToggle.syncState();

        drawerListView = (ListView) findViewById(R.id.drawer_listView);
        setupDrawer();

    }

setupDrawer()方法在哪里

private void setupDrawer() {
        // SELECT * FROM Sections where Fk == 0;
        sectionsList = new RushSearch().whereEqual("Fk", 0).find(Sections.class);
        Log.d("ELEMENT", "" + sectionsList.size());
        drawerListViewAdapter = new DrawerListViewAdapter(sectionsList, getApplicationContext());

        // Adapter che si occupa di popolare il drawer
        drawerListView.setAdapter(drawerListViewAdapter);

        // Listner per il click su un elemento del drawer
        drawerListView.setOnItemClickListener(click);
    }

如果我在 try-catch 中从onCreate()或callWebservice()之后调用此方法，我会遇到同样的问题。saveSections(response.getJSONArray("Sections"));

于 2015-12-01T12:13:46.393 回答
0

我认为您应该调用这部分代码：

// SELECT * FROM Sections where Fk == 0;
sectionsList = new RushSearch().whereEqual("Fk", 0).find(Sections.class);
Log.d("ELEMENTI",""+sectionsList.size());
drawerListViewAdapter = new DrawerListViewAdapter(sectionsList, getApplicationContext());

// Adapter che si occupa di popolare il drawer
drawerListView.setAdapter(drawerListViewAdapter);

在 saveSections() 方法完成后。像这样的东西：

private void callWebservice() {

String tag_json_obj = "GetItem";
String url = String.format("http://digitalbox.getsandbox.com/item");
JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
    @Override
    public void onResponse(JSONObject response) {
        try {
            saveSections(response.getJSONArray("Sections"));
// SELECT * FROM Sections where Fk == 0;
sectionsList = new RushSearch().whereEqual("Fk", 0).find(Sections.class);
Log.d("ELEMENTI",""+sectionsList.size());
drawerListViewAdapter = new DrawerListViewAdapter(sectionsList, getApplicationContext());

// Adapter che si occupa di popolare il drawer
drawerListView.setAdapter(drawerListViewAdapter);
        } catch (JSONException e) {
            e.printStackTrace();
        }

    }
}, new Response.ErrorListener() {
    public void onErrorResponse(VolleyError error) {
        VolleyLog.d("Settings", "Error: " + error.getMessage());
    }
}) {
    @Override
    public Map<String, String> getHeaders() throws AuthFailureError {
        HashMap<String, String> headers = new HashMap<String, String>();
        headers.put("Content-Type", "application/json");
        headers.put("Accept", "application/json");
        return headers;
    }
};
NetworkController.getInstance().addToRequestQueue(jsonObjectRequest, tag_json_obj);

}

于 2015-11-30T22:40:54.873 回答