从活动转到片段并转到另一个片段

Question

我是android新手，看起来我无法理解一件事。

我想从MainActivity跳转到MainFragment。里面有一个按钮。当onClickListener被触发时，它应该跳转到另一个ResultFragment。但我似乎无法理解如何去做。

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:id="@+id/activity_main" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:paddingBottom="@dimen/activity_vertical_margin" 
    android:paddingLeft="@dimen/activity_horizontal_margin" 
    android:paddingRight="@dimen/activity_horizontal_margin" 
    android:paddingTop="@dimen/activity_vertical_margin" 
    tools:context="com.something.MainActivity"> 

    <fragment 
     android:id="@+id/container" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     tools:layout="@layout/fragment_main" /> 
</RelativeLayout> 

public class MainActivity extends AppCompatActivity { 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     Fragment fragment = new MainFragment(); 
     getSupportFragmentManager().beginTransaction().replace(R.id.container, fragment, null).commit(); 
    } 
} 

public class MainFragment extends Fragment { 
    public MainFragment() { 
    } 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
          Bundle savedInstanceState) { 
     View rootView = inflater.inflate(R.layout.fragment_main, container, false); 

     Button button = (Button) rootView.findViewById(R.id.button); 

     button.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Toast.makeText(getContext(), "iskviesta", Toast.LENGTH_SHORT).show(); 
       getFragmentManager().beginTransaction().replace(R.id.container, new ResultFragment()).commit(); 
      } 
     }); 

     return rootView; 
    } 
} 

public class ResultFragment extends Fragment { 

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

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
          Bundle savedInstanceState) { 
     View rootView = inflater.inflate(R.layout.fragment_result, container, false); 

     return rootView; 
    } 
} 

我在做什么错？该应用程序甚至没有开始。

E/AndroidRuntime: FATAL EXCEPTION: main 
        Process: com.something, PID: 14245 
        java.lang.RuntimeException: Unable to start activity ComponentInfo{com.something/com.something.MainActivity}: android.view.InflateException: Binary XML file line #13: Binary XML file line #13: Error inflating class fragment 
         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665) 
         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726) 
         at android.app.ActivityThread.-wrap12(ActivityThread.java) 
         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477) 
         at android.os.Handler.dispatchMessage(Handler.java:102) 
         at android.os.Looper.loop(Looper.java:154) 
         at android.app.ActivityThread.main(ActivityThread.java:6119) 
         at java.lang.reflect.Method.invoke(Native Method) 
         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) 
         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776) 
        Caused by: android.view.InflateException: Binary XML file line #13: Binary XML file line #13: Error inflating class fragment 
        Caused by: android.view.InflateException: Binary XML file line #13: Error inflating class fragment 
        Caused by: java.lang.NullPointerException 
         at java.lang.VMClassLoader.findLoadedClass(Native Method) 
         at java.lang.ClassLoader.findLoadedClass(ClassLoader.java:742) 
         at java.lang.ClassLoader.loadClass(ClassLoader.java:362) 
         at java.lang.ClassLoader.loadClass(ClassLoader.java:312) 
         at android.support.v4.app.Fragment.isSupportFragmentClass(Fragment.java:459) 
         at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:3321) 
         at android.support.v4.app.FragmentController.onCreateView(FragmentController.java:120) 
         at android.support.v4.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:378) 
         at android.support.v4.app.BaseFragmentActivityHoneycomb.onCreateView(BaseFragmentActivityHoneycomb.java:33) 
         at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:79) 
         at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:777) 
         at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:727) 
         at android.view.LayoutInflater.rInflate(LayoutInflater.java:858) 
         at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:821) 
         at android.view.LayoutInflater.inflate(LayoutInflater.java:518) 
         at android.view.LayoutInflater.inflate(LayoutInflater.java:426) 
         at android.view.LayoutInflater.inflate(LayoutInflater.java:377) 
         at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:288) 
         at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:143) 
         at com.something.MainActivity.onCreate(MainActivity.java:12) 
         at android.app.Activity.performCreate(Activity.java:6679) 
         at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118) 
         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2618) 
         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726) 
         at android.app.ActivityThread.-wrap12(ActivityThread.java) 
         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477) 
         at android.os.Handler.dispatchMessage(Handler.java:102) 
         at android.os.Looper.loop(Looper.java:154) 
         at android.app.ActivityThread.main(ActivityThread.java:6119) 
         at java.lang.reflect.Method.invoke(Native Method) 
         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) 
         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776) 

Answer 1

在XML使用的FrameLayout而不是片段的：

<FrameLayout 
     android:id="@+id/container" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" /> 

使用片段标签不会允许你做的视图片段交易。

Answer 2

你应该在你的听众使用getSupportFragmentManager()代替getFragmentManager：

button.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Toast.makeText(getContext(), "iskviesta", Toast.LENGTH_SHORT).show(); 
       getSupportFragmentManager().beginTransaction().replace(R.id.container, new ResultFragment()).commit(); 
      } 
     }); 

并在你的XML代码的FrameLayout remplace你的片段布局。

希望这会有所帮助。

对不起，我的英语。