android - 用另一个 fragment 替换一个 fragment

Question

我想用新的 Fragment 替换旧的 Fragment，但我仍然看到旧的 Fragment 的按钮仍然可见在新 fragment 中。

在旧版本中，单击按钮

FragmentTransaction transaction = getFragmentManager().beginTransaction();
Fragment newFragment = GenericMood.newInstance("a","b");

// Replace whatever is in the fragment_container view with this fragment,
// and add the transaction to the back stack if needed
transaction.replace(R.id.allmoods, newFragment);
transaction.addToBackStack(null);
transaction.commitAllowingStateLoss();

我可以用新的 Fragment 替换旧的 Fragment，但是 R.id.allmoods Fragment 中的按钮在新的 Fragment< 之上仍然可见.

我尝试使用下面给出的代码。

FragmentTransaction transaction = getFragmentManager().beginTransaction();
Fragment newFragment = GenericMood.newInstance("a","b");

// Replace whatever is in the fragment_container view with this fragment,
// and add the transaction to the back stack if needed
transaction.replace(((ViewGroup)getView().getParent()).getId(), newFragment);
transaction.addToBackStack(null);
transaction.commitAllowingStateLoss();

XML 文件:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/allmoods"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorPrimary"
    tools:context="com.moodoff.Moods">
     <Button
        android:text="Button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="64dp"
        android:id="@+id/btn_btn"
        android:height="80dp"
        android:width="100dp"
        android:onClick="putmeoff"
        android:layout_marginLeft="17dp"
        android:layout_marginStart="17dp"/>
</RelativeLayout>

这是应该替换上面的 fragment :

<FrameLayout 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:id="@+id/genericmood"
    android:layout_height="match_parent"
    android:background="@color/colorPrimary"
    tools:context="com.moodoff.GenericMood">
    <!-- TODO: Update blank fragment layout -->


    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#000000"
        android:layout_gravity="fill_horizontal"
        android:id="@+id/floatingButtons"
        >
        <android.support.design.widget.FloatingActionButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="1dp"
            android:layout_marginRight="14dp"
            app:backgroundTint="#ffffff"
            android:layout_alignParentTop="true"
            android:layout_alignParentRight="true"
            android:layout_alignParentEnd="true"
            android:src="@drawable/cameraicon"
            android:id="@+id/btn_camera"
            app:fabSize="mini"
            />
    </RelativeLayout>
</FrameLayout>

两者都不行。该怎么办？更新:替换为正确的容器后，按钮消失了，但新 fragment 未正确实例化。我得到一个纯白的屏幕。

my activity_alltabs.xml looks like this: 

<?xml version="1.0" encoding="utf-8"?>
    <android.support.design.widget.CoordinatorLayout 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:id="@+id/main_content"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        tools:context="com.moodoff.AllTabs">

        <android.support.design.widget.AppBarLayout
            android:id="@+id/appbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:theme="@style/AppTheme.AppBarOverlay">

            <android.support.design.widget.TabLayout
                android:id="@+id/tabs"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:background="@android:color/background_dark" />

        </android.support.design.widget.AppBarLayout>

        <android.support.v4.view.ViewPager
            android:id="@+id/container"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior" />

    </android.support.design.widget.CoordinatorLayout>

Answer 1

我以前研究过 fragment ，希望这对您有所帮助，让您更好地理解流程。首先，您的 MainActivity.xml 文件将如下所示:

<?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"
   app:layout_behavior="@string/appbar_scrolling_view_behavior"
   tools:context="com.example.activity.HomeActivity">


    //This frameLayout will contain all your fragments view.
   <FrameLayout
      android:id="@+id/container_view"
      android:layout_width="match_parent"
      android:layout_height="match_parent">
    </FrameLayout>

 </RelativeLayout>

接下来，您创建两个 fragment ，它们的 XML 如下所示:fragment1.xml

<RelativeLayout 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"
    android:clickable="true" // important to have this
    tools:context=".fragments.frament1">

     <Button
        android:id="@+id/btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"/>

 </RelativeLayout>

下一个 fragment 看起来与上面提到的完全一样。这是 Fragment1.class:

public class Fragment1 extends Fragment implements View.OnClickListener {
Button btn;

   public Fragment1() {
    // Required empty public constructor
}

     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment1, container, false);
        view.setBackgroundColor(Color.WHITE);

       //Perform required conditions and return view 
       button = (Button) view.findViewById(R.id.btn);
       button.setOnClickListener(this);

       return view;
      }

        public void onClick(View v) {

             switch(v.getId())
             {
                case R.id.btn: 
                 //replace current fragment on button click

                 Fragment fragment2= new Fragment2();

                 getFragmentManager().beginTransaction().
                 replace(R.id.container_view, fragment2).
                 addToBackStack("frags").commit();

               break;
             }
        }
 }

而 Fragment2 将如下所示:

 public class Fragment2 extends Fragment{
 String TAG = "Fragment2";


     public Fragment2() {
      // Required empty public constructor
   }

     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

          View view = inflater.inflate(R.layout.fragment2,container,false);
          view.setBackgroundColor(Color.WHITE);
       return view;
    }
}

如前所述，xml 文件与 fragment1.xml 相同。这里更重要的是，主要 Activity 将包含一个布局，当用户切换 fragment 时，该布局将采用 fragment View 。因此，我们使用 replace 方法，它只会用我们指定的 fragment View 替换以前的 View 。