我有一些有线问题。在我向下滚动后，当我试图关闭DrawerLayout时，应用程序崩溃了。如果您需要我将添加的任何代码。 感谢。
我希望此代码能为您提供帮助。当我滚动DrawerLayout直到结束并按下某些东西或尝试关闭它时，应用程序就会崩溃。
public class newsfeed_activity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
private android.support.v7.widget.Toolbar toolbar_main;
private android.support.v7.widget.Toolbar toolbar_web;
private ListAdapter listadapter;
private SwipeRefreshLayout refreshList;
private ListView listView_article;
private Handler handler = new Handler();
private WebView web;
private WebBackForwardList webBackForwardList;
private DrawerLayout drawer;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.newsfeed_activity);
Intent welcome = new Intent(this,Explanation.class);
startActivity(welcome);
if(FacebookAndGoogle.isLoggedWithFacebook())
{
FacebookAndGoogle.getBitmapFromURL(FacebookAndGoogle.getCurrentFacebookProfile().getProfilePictureUri(500, 500).toString());
FacebookAndGoogle.setFullName(FacebookAndGoogle.getCurrentFacebookProfile().getName());
}
else if(FacebookAndGoogle.isLoggedWithGoogle())
{
FacebookAndGoogle.getBitmapFromURL(FacebookAndGoogle.getCurrentGoogleProfile().getImage().getUrl().replace("sz=50", "sz=500").toString());
FacebookAndGoogle.setFullName(FacebookAndGoogle.getCurrentGoogleProfile().getDisplayName());
}
createWebView();
toolbar_web = (android.support.v7.widget.Toolbar) findViewById(R.id.toolbar_web);
setSupportActionBar(toolbar_web);
getSupportActionBar().setDisplayShowTitleEnabled(false);
toolbar_web.setVisibility(View.GONE);
toolbar_main = (android.support.v7.widget.Toolbar) findViewById(R.id.toolbar_main);
setSupportActionBar(toolbar_main);
getSupportActionBar().setDisplayShowTitleEnabled(false);
saveInInternalFolder("NewzBay", "check");
Vector<Article> articles = new Vector<Article>();
articles.add(new Article("Subject", "כותרת ראשית 1", "Second Headline", BitmapFactory.decodeResource(getResources(), R.drawable.anchor), null, "Site", "http://www.ynet.co.il/articles/0,7340,L-4740637,00.html", 605, 24, true));
articles.add(new Article("Subject", "כותרת ראשית 2", "Second Headline", BitmapFactory.decodeResource(getResources(), R.drawable.anchor), null, "Site", "http://www.google.co.il", 524, 53, false));
articles.add(new Article("Subject", "כותרת ראשית 3", "Second Headline", BitmapFactory.decodeResource(getResources(), R.drawable.anchor), null, "Site", "http://www.facebook.com", 106, 40, true));
listView_article = (ListView) findViewById(R.id.listView_articles);
listadapter = new ArticleAdapter(this, articles, web, toolbar_main, toolbar_web);
listView_article.setAdapter(listadapter);
createSwipeRefreshLayout();
drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar_main, R.string.navigation_drawer_open, R.string.navigation_drawer_close) {
@Override
public void onDrawerSlide(View drawerView, float slideOffset) {
super.onDrawerSlide(drawerView, slideOffset);
drawerHandler(drawer);
}
};
toggle.setDrawerIndicatorEnabled(false);
toolbar_main.setNavigationIcon(R.drawable.anchor);
toolbar_main.setNavigationOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
drawerHandler(drawer);
}
});
drawer.setDrawerListener(toggle);
toggle.syncState();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
}
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.nav_hot_news) {
Intent intent = new Intent(this, ExploreArticles.class);
startActivity(intent);
this.onStop();
} else if (id == R.id.nav_news) {
} else if (id == R.id.nav_economy) {
} else if (id == R.id.nav_sport) {
} else if (id == R.id.nav_settings) {
Intent settings = new Intent(this, settings_activity.class);
startActivity(settings);
this.onStop();
}
else if (id == R.id.nav_discconect) {
if (FacebookAndGoogle.isLoggedWithGoogle()) {
Plus.AccountApi.clearDefaultAccount(FacebookAndGoogle.getmGoogleApiClient());
FacebookAndGoogle.getmGoogleApiClient().disconnect();
FacebookAndGoogle.getmGoogleApiClient().connect();
}
else if(FacebookAndGoogle.isLoggedWithFacebook())
{
FacebookAndGoogle.reset(BitmapFactory.decodeResource(getResources(), R.drawable.user_icon));
LoginManager.getInstance().logOut();
}
FacebookAndGoogle.reset(BitmapFactory.decodeResource(getResources(), R.drawable.user_icon));
Intent intent = new Intent(this, entrance.class);
startActivity(intent);
finish();
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
活动的XML
<?xml version="1.0" encoding="utf-8"?>
<include
layout="@layout/app_bar_newsfeed_activity"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<android.support.design.widget.NavigationView
android:id="@+id/nav_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:fitsSystemWindows="true"
app:headerLayout="@layout/nav_header_newsfeed_activity"
app:menu="@menu/newsfeed_activity_drawer" />
我找到了Logcat：
03-03 14:11:27.390 2115-2115/magshimim.newzbay E/AndroidRuntime: FATAL EXCEPTION: main
Process: magshimim.newzbay, PID: 2115
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
at magshimim.newzbay.newsfeed_activity.drawerHandler(newsfeed_activity.java:241)
at magshimim.newzbay.newsfeed_activity.access$100(newsfeed_activity.java:39)
at magshimim.newzbay.newsfeed_activity$1.onDrawerSlide(newsfeed_activity.java:94)
at android.support.v4.widget.DrawerLayout.dispatchOnDrawerSlide(DrawerLayout.java:773)
at android.support.v4.widget.DrawerLayout.setDrawerViewOffset(DrawerLayout.java:784)
at android.support.v4.widget.DrawerLayout$ViewDragCallback.onViewPositionChanged(DrawerLayout.java:1848)
at android.support.v4.widget.ViewDragHelper.continueSettling(ViewDragHelper.java:737)
at android.support.v4.widget.DrawerLayout.computeScroll(DrawerLayout.java:1130)
at android.view.View.updateDisplayListIfDirty(View.java:14986)
at android.view.View.getDisplayList(View.java:15022)
at android.view.View.draw(View.java:15789)
at android.view.ViewGroup.drawChild(ViewGroup.java:3678)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3472)
at android.view.View.updateDisplayListIfDirty(View.java:14994)
at android.view.View.getDisplayList(View.java:15022)
at android.view.View.draw(View.java:15789)
at android.view.ViewGroup.drawChild(ViewGroup.java:3678)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3472)
at android.view.View.updateDisplayListIfDirty(View.java:14994)
at android.view.View.getDisplayList(View.java:15022)
at android.view.View.draw(View.java:15789)
at android.view.ViewGroup.drawChild(ViewGroup.java:3678)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3472)
at android.view.View.updateDisplayListIfDirty(View.java:14994)
at android.view.View.getDisplayList(View.java:15022)
at android.view.View.draw(View.java:15789)
at android.view.ViewGroup.drawChild(ViewGroup.java:3678)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3472)
at android.view.View.updateDisplayListIfDirty(View.java:14994)
at android.view.View.getDisplayList(View.java:15022)
at android.view.View.draw(View.java:15789)
at android.view.ViewGroup.drawChild(ViewGroup.java:3678)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3472)
at android.view.View.draw(View.java:16071)
at android.widget.FrameLayout.draw(FrameLayout.java:592)
at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:2916)
at android.view.View.updateDisplayListIfDirty(View.java:14999)
at android.view.View.getDisplayList(View.java:15022)
at android.view.ThreadedRenderer.updateViewTreeDisplayList(ThreadedRenderer.java:275)
at android.view.ThreadedRenderer.updateRootDisplayList(ThreadedRenderer.java:281)
at android.view.ThreadedRenderer.draw(ThreadedRenderer.java:320)
at android.view.ViewRootImpl.draw(ViewRootImpl.java:2741)
at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2573)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2165)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1180)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6558)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:777)
at android.view.Choreographer.doCallbacks(Choreographer.java:590)
at android.view.Choreographer.doFrame(Choreographer.java:560)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:763)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5832)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)
答案 0 :(得分：0)
为什么找到onItemSelected Method.You也找到了view并点击了view child.Your process就像这样工作。 找到抽屉视图 selecet孩子。 并再次找到Dirawerview。所有时间再次查找视图。 `
DrawerLayout drawer =（DrawerLayout）findViewById（R.id.drawer_layout）; //删除此行，因为您已经在oncreate中 drawer.closeDrawer（GravityCompat.START）;
`
答案 1 :(得分：0)
错误发生在您的活动drawerHandle()中。您最有可能尝试使用findViewById（）获取对视图的引用而不是获取视图。发布drawerHandle(...)方法的正文，否则很难确切地说出错误。
答案 2 :(得分：0)
Ty for Dmitriy :) 发生的事情是我试图将文本和图片设置为空引用。
private void drawerHandler(DrawerLayout drawer)
{
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
}
else {
drawer.openDrawer(GravityCompat.START);
}
TextView userFullName = (TextView) drawer.findViewById(R.id.tv_userFullName);
if(userFullName != null)
{
userFullName.setText(FacebookAndGoogle.getFullName());
}
ImageButton userPic = (ImageButton) drawer.findViewById(R.id.ib_userPic);
if(userPic != null)
{
userPic.setImageBitmap(RoundedImageView.getCroppedBitmap(FacebookAndGoogle.getProfilePic(), 240));
}
}