我创建了一个 Home Activity ,其中包括带有 fragment 的 Tablayout 和 Navigation Drawer
onclick。我已将 fragmentTransaction.addToBackStack(null).commit();
包含在 fragment 事务代码中以返回到之前的 Activity。
我想要的要求来自 Activity with tablayout-->NavigationDrawer-->Fragment1--> On BackButtonPress-->MainActivity with tablayout。
但是,现在我可以移动到 Fragment1,当返回到 MainActivity 时, View 变为 填充白色(如果我使用 mainLayout.removeAllViews()
;如果不使用 mainLayout.removeAllViews(); ,然后 fragment 与MainActivity重叠
)
1.我的主要 Activity
2. fragment
3.当我回到mainactivty时
现在我在 MainActivity 中看不到 tablayout。
谁能帮帮我。
mainactivity_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context=".HomeActivity"
android:id="@+id/mainlayout"
tools:showIn="@layout/app_bar_home">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/rel">
<RelativeLayout
android:id="@+id/main_layout1"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<android.support.design.widget.TabLayout
android:id="@+id/tab_layout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
android:elevation="6dp"
android:minHeight="?attr/actionBarSize"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"/>
<android.support.v4.view.ViewPager
android:id="@+id/pager1"
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:layout_below="@id/tab_layout1"/>
</RelativeLayout>
</RelativeLayout>
</RelativeLayout>
主 Activity .java
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.design.widget.NavigationView;
import android.support.design.widget.TabLayout;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.view.GravityCompat;
import android.support.v4.view.ViewPager;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.RelativeLayout;
import java.io.File;
import java.util.ArrayList;
public class HomeActivity extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.setDrawerListener(toggle);
toggle.syncState();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
TabLayout tabLayout1 = (TabLayout) findViewById(R.id.tab_layout1);
tabLayout1.addTab(tabLayout1.newTab().setIcon(R.drawable.tab_ic_home));
tabLayout1.addTab(tabLayout1.newTab().setIcon(R.drawable.tab_ic_map));
tabLayout1.addTab(tabLayout1.newTab().setIcon(R.drawable.tab_ic_login));
tabLayout1.setTabGravity(TabLayout.GRAVITY_FILL);
final ViewPager viewPager1 = (ViewPager) findViewById(R.id.pager1);
final PagerAdapter1 adapter = new PagerAdapter1
(getSupportFragmentManager(), tabLayout1.getTabCount());
viewPager1.setAdapter(adapter);
viewPager1.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout1));
tabLayout1.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager1.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
}
@Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.home, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
// Handle navigation view item clicks here.
int id = item.getItemId();
RelativeLayout mainLayout=(RelativeLayout)findViewById(R.id.main_content);
if (id == R.id.nav_login) {
LoginFragment fragment = new LoginFragment();
// mainLayout.removeAllViews();
fragmentTransaction.replace(R.id.mainlayout, fragment);
fragmentTransaction.addToBackStack(null).commit();
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
}
fragment .java
import android.annotation.SuppressLint;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
public class ContactFragment extends Fragment implements OnMapReadyCallback {
private GoogleMap mMap;
Button call;
public ContactFragment() {
// Required empty public constructor
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.activity_contact,container,false);
call = (Button) v.findViewById(R.id.button5);
call.setOnClickListener(new View.OnClickListener() {
@SuppressLint("NewApi")
@Override
public void onClick(View v) {
Intent i = new Intent(Intent.ACTION_DIAL);
i.setData(Uri.parse("tel:7034409615"));
startActivity(i);
}
});
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getChildFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
return v;
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
// Add a marker in Sydney and move the camera
LatLng sydney = new LatLng(9.2700, 76.7800);
mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Pathanamthitta"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
}
}
最佳答案
正如我在评论中所建议的,为了弄清楚 fragment 显示的问题,您可以尝试查看哪些 fragment 被添加到后退堆栈中,如下所示
Log.d("FragmentList",getSupportFragmentManager().getFragments().toString();
你可以把它放在 onBackPressed()
,onNavigationItemSelected()
根据您的反馈,这对您有所帮助,您解决了问题。
还有一些布局设计问题: 您当前的方法是将 fragment 添加到相对布局中。我相信这会导致一些 View 问题。推荐的方法是将 fragment 添加到 FrameLayout 中,如 docs 中所述。 此外,您可能希望将用于 fragment 的所有内容移到 View 之外 我已经按照文档中推荐的指南重写了您的布局。 P.S 我还没有测试它的显示方式。您可能需要调整一些布局参数。
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!--
Layout for fragments
-->
<FrameLayout
android:id="@+id/mainlayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:showIn="@layout/app_bar_home">
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/rel">
<RelativeLayout
android:id="@+id/main_layout1"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.TabLayout
android:id="@+id/tab_layout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
android:elevation="6dp"
android:minHeight="?attr/actionBarSize"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" android:orientation="horizontal"/>
<android.support.v4.view.ViewPager
android:id="@+id/pager1"
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:layout_below="@id/tab_layout1"/>
</RelativeLayout>
</RelativeLayout>
</LinearLayout>
此外,您还在布局中定义了多个 Activity ,例如 tools:context=".MainActivity"
和 tools:context=".HomeActivity"
我想这只是未经编辑的复制粘贴, 但也可能导致一些问题。
希望你觉得它有用:)
关于android - fragment 到 Activity Backstack 返回空白 View ,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/33493612/