抽屉式导航栏的ListView为空 [英] Navigation Drawer ListView is empty
问题描述
我与第一个活动是一个登录页面的应用程序。当用户成功登录，他看到他的项目。我使用 ListFragment 来diplay这个名单（因为我也有用户认为，在登录页面的一半公益性项目）。而我增加了抽屉式导航的活动，他登录后，经过了很多困惑，我能够加入导航抽屉上的活动，但它有一个空列表。
I have an app with the first activity being a log-in page. When the user successfully logs in he sees his projects. I am using ListFragment to diplay this list(since I also have public projects which the user sees in one-half of the login page). And I am adding a Navigation Drawer to the activity after he logs in. After a lot of confusion I was able to add the Navigation Drawer on the activity, but the it has an empty list.
DrawerActivity.java：
public class DrawerActivity extends Activity {
private DrawerLayout mDrawerLayout;
private ListView mDrawerList;
private ActionBarDrawerToggle mDrawerToggle;
private CharSequence mDrawerTitle;
private CharSequence mTitle;
private String[] mScreenTitles;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.private_project_list);
mTitle = mDrawerTitle = getTitle();
mScreenTitles = getResources().getStringArray(R.array.screen_titles);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerList = (ListView) findViewById(R.id.left_drawer);
mDrawerList.setAdapter(new ArrayAdapter<String>(this,
R.layout.drawer_list_item, mScreenTitles));
//mDrawerList.setOnItemClickListener(new DrawerItemClickListener());
// enable ActionBar app icon to behave as action to toggle nav drawer
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeButtonEnabled(true);
// ActionBarDrawerToggle ties together the the proper interactions
// between the sliding drawer and the action bar app icon
mDrawerToggle = new ActionBarDrawerToggle(
this, /* host Activity */
mDrawerLayout, /* DrawerLayout object */
R.drawable.ic_navigation_drawer, /* nav drawer image to replace 'Up' caret */
R.string.drawer_open, /* "open drawer" description for accessibility */
R.string.drawer_close /* "close drawer" description for accessibility */
) {
public void onDrawerClosed(View view) {
getActionBar().setTitle(mTitle);
invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
}
public void onDrawerOpened(View drawerView) {
getActionBar().setTitle(mDrawerTitle);
invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
if (savedInstanceState == null) {
selectItem(0);
}
}
/* Called whenever we call invalidateOptionsMenu() */
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
// If the nav drawer is open, hide action items related to the content view
return super.onPrepareOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// The action bar home/up action should open or close the drawer.
// ActionBarDrawerToggle will take care of this.
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
return super.onOptionsItemSelected(item);
}
/* The click listner for ListView in the navigation drawer */
private class DrawerItemClickListener implements ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectItem(position);
}
}
private void selectItem(int position) {
}
}
PrivateProjectListActivity.java：（它扩展了DrawerActivity）
PrivateProjectListActivity.java: (which extends the DrawerActivity)
public class PrivateProjectListActivity extends DrawerActivity {
private final static String TAG_TITLE = "title";
private final static String TAG_ANIM_ARRAY_ID = "animation_array";
private final static String TAG_PROJECTS = "projects";
private final static String TAG_ID = "id";
JSONArray projects = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.private_project_list);
new HttpGetHandler().execute();
}
private class HttpGetHandler extends AsyncTask<String, Void, Void> {
@Override
protected Void doInBackground(String... params) {
String jsonUrl = "http://canvasflip.com/protected/actions/user.php?action=get-projects&network=Escort&index=0&count=100";
HttpGet httpGet = new HttpGet(jsonUrl);
try {
HttpResponse httpResponse = MainActivity.httpClient.execute(httpGet);
HttpEntity httpEntity = httpResponse.getEntity();
InputStream content = httpEntity.getContent();
String result = convertToString(content);
JSONObject jsonObject = new JSONObject(result);
projects = jsonObject.getJSONArray(TAG_PROJECTS);
PrivateProjectListActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
try{
ArrayList<String> projectTitle = new ArrayList<String>();
ArrayList<String> imageId = new ArrayList<String>();
ArrayList<String> playId = new ArrayList<String>();
for(int i=0; i<projects.length(); i++) {
JSONObject p = projects.getJSONObject(i);
String title = p.getString(TAG_TITLE);
String id = p.getString(TAG_ID);
String array_anim_id = p.getString(TAG_ANIM_ARRAY_ID);
String imgId = array_anim_id.substring(0, 4);
projectTitle.add(title);
imageId.add(imgId);
playId.add(id);
}
String[] arrProjectTitle = new String[projectTitle.size()];
String[] arrImageId = new String[imageId.size()];
final String[] pid = new String[playId.size()];
for(int i = 0; i<projectTitle.size(); i++)
arrProjectTitle[i] = projectTitle.get(i);
for(int j = 0; j<imageId.size(); j++)
arrImageId[j] = imageId.get(j);
for(int k = 0; k<playId.size(); k++)
pid[k] = playId.get(k);
Bundle b = new Bundle();
b.putStringArray("projectTitle", arrProjectTitle);
b.putStringArray("imageId", arrImageId);
PrivateProjectsListFragment fragment = new PrivateProjectsListFragment();
fragment.setArguments(b);
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
ft.replace(R.id.privateProjectsContainer,fragment);
ft.commit();
}catch(Exception e) {
}
}
});
}catch(Exception e) {
}
return null;
}
public String convertToString(InputStream inputStream) throws IOException {
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
String line = "";
String result = "";
while((line = bufferedReader.readLine())!=null) {
result += line;
}
inputStream.close();
return result;
}
}
}
private_project_list.xml：
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout
android:layout_height="match_parent"
android:layout_width="match_parent"
android:id="@+id/drawer_layout"
xmlns:android="http://schemas.android.com/apk/res/android">
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent"
android:id="@+id/privateProjectsContainer"
android:background="#eeeeee">
</FrameLayout>
<ListView
android:id="@+id/left_drawer"
android:layout_width="240dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:choiceMode="singleChoice"
android:divider="@android:color/transparent"
android:dividerHeight="0dp"
android:background="#111"/>
</android.support.v4.widget.DrawerLayout>
另外，切换按钮也不能正常工作。我只看到一个向后的箭头，并没有发生在单击它，我必须从左边滑动打开抽屉。
Plus , the toggle button is also not working. I only see a back arrow , and nothing happens on clicking it , I have to slide from the left to open the drawer.
推荐答案
我建议你做它像下面这样：
I suggest to you to do it like following:
在 DrawerActivity ，只创建了抽屉式导航，而无需使用的onCreate（），但使用在onStart（）。在的onCreate（）将扩展该活动被称为 DrawerActivity 在那里你会打电话给的setContentView
In the DrawerActivity, create only the navigation drawer, without using onCreate(), but using onStart(). The onCreate() will be called in the activity that extends DrawerActivity and there you'll call setContentView
您的类看起来像这样：
public class DrawerActivity extends Activity {
private DrawerLayout mDrawerLayout;
private ListView mDrawerList;
private ActionBarDrawerToggle mDrawerToggle;
private CharSequence mDrawerTitle;
private CharSequence mTitle;
private String[] mScreenTitles;
@Override
protected void onStart(){
super.onStart();
mTitle = mDrawerTitle = getTitle();
mScreenTitles = getResources().getStringArray(R.array.screen_titles);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerList = (ListView) findViewById(R.id.left_drawer);
mDrawerList.setAdapter(new ArrayAdapter<String>(this,
R.layout.drawer_list_item, mScreenTitles));
//mDrawerList.setOnItemClickListener(new DrawerItemClickListener());
// enable ActionBar app icon to behave as action to toggle nav drawer
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeButtonEnabled(true);
// ActionBarDrawerToggle ties together the the proper interactions
// between the sliding drawer and the action bar app icon
mDrawerToggle = new ActionBarDrawerToggle(
this, /* host Activity */
mDrawerLayout, /* DrawerLayout object */
R.drawable.ic_navigation_drawer, /* nav drawer image to replace 'Up' caret */
R.string.drawer_open, /* "open drawer" description for accessibility */
R.string.drawer_close /* "close drawer" description for accessibility */
) {
public void onDrawerClosed(View view) {
getActionBar().setTitle(mTitle);
invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
}
public void onDrawerOpened(View drawerView) {
getActionBar().setTitle(mDrawerTitle);
invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
if (savedInstanceState == null) {
selectItem(0);
}
}
/* Called whenever we call invalidateOptionsMenu() */
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
// If the nav drawer is open, hide action items related to the content view
return super.onPrepareOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// The action bar home/up action should open or close the drawer.
// ActionBarDrawerToggle will take care of this.
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
return super.onOptionsItemSelected(item);
}
/* The click listner for ListView in the navigation drawer */
private class DrawerItemClickListener implements ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectItem(position);
}
}
private void selectItem(int position) {
}
}
在要在其中使用抽屉，你必须建立你的布局像你这样的电流 private_project_list.xml ，使用DrawerLayout作为主容器，你的活动doby布局，它的第一个孩子，抽屉式导航栏布局的第二个孩子。然后，扩展了活动 DrawerActivity 。
In every activity in which you want to use the Drawer, you have to build you layout like you current private_project_list.xml, using DrawerLayout as main container, the doby layout of your activity as its first child and the navigation drawer layout as second child. Then, extends the activity to DrawerActivity.
Antoher的建议是让在格兰列表 DrawerActivity ，要求 HttpGetHandler（）在它的内部，你必须只设置适配器当阵列将满，否则，你传递给适配器一个空数组，所以该列表是空的。
Antoher suggestion is to get the list in teh DrawerActivity, calling HttpGetHandler() inside of it, you have to set the adapter only when the array will be full, otherwise you pass to the adapter an empty array, so the list will be empty.
关于未显示菜单按钮
在DrawerActivity似乎缺少了操作栏的一些方法，尝试添加以下
In DrawerActivity seems missing some methods for the action bar, try add the following
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Sync the toggle state after onRestoreInstanceState has occurred.
mDrawerToggle.syncState();
}
@Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
mDrawerToggle.onConfigurationChanged(newConfig);
}
这篇关于抽屉式导航栏的ListView为空的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
