爲什麼我的應用在模擬器運行後仍然崩潰？

-1

試圖創建一個應用程序，我試圖創建一個簡單的轉換器。當我運行模擬器時，應用程序崩潰，所以我不知道它爲什麼崩潰。我可以讓我運行模擬器爲什麼我的應用在模擬器運行後仍然崩潰？

這是我在logcat中看到：

07-09 20:28:10.220 17354-17354/com.example.adrew.convertmidterm   E/AndroidRuntime﹕ FATAL EXCEPTION: main 
Process: com.example.adrew.convertmidterm, PID: 17354 
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.adrew.convertmidterm/com.example.adrew.convertmidterm.MainActivity}: android.view.InflateException: Binary XML file line #1: Error inflating class fragment 
     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325) 
     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390) 
     at android.app.ActivityThread.access$800(ActivityThread.java:151) 
     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) 
     at android.os.Handler.dispatchMessage(Handler.java:102) 
     at android.os.Looper.loop(Looper.java:135) 
     at android.app.ActivityThread.main(ActivityThread.java:5257) 
     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:903) 
     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 
Caused by: android.view.InflateException: Binary XML file line #1: Error inflating class fragment 
     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:763) 
     at android.view.LayoutInflater.inflate(LayoutInflater.java:482) 
     at android.view.LayoutInflater.inflate(LayoutInflater.java:414) 
     at android.view.LayoutInflater.inflate(LayoutInflater.java:365) 
     at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:378) 
     at android.app.Activity.setContentView(Activity.java:2145) 
     at com.example.adrew.convertmidterm.MainActivity.onCreate(MainActivity.java:14) 
     at android.app.Activity.performCreate(Activity.java:5990) 
     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106) 


     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390) 
    at android.app.ActivityThread.access$800(ActivityThread.java:151) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) 
            at android.os.Handler.dispatchMessage(Handler.java:102) 
            at android.os.Looper.loop(Looper.java:135) 
            at android.app.ActivityThread.main(ActivityThread.java:5257) 
            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:903) 
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 
    Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on a null object reference at com.example.adrew.convertmidterm.MainActivityFragment.onCreateView(MainActivityFragment.java:33) 
      at android.app.Fragment.performCreateView(Fragment.java:2053) 
      at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:870) 
      at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1045) 
      at android.app.FragmentManagerImpl.addFragment(FragmentManager.java:1147) 
      at android.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2116) 
      at android.app.Activity.onCreateView(Activity.java:5328) 
      at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:733) 
            at android.view.LayoutInflater.inflate(LayoutInflater.java:482) 
            at android.view.LayoutInflater.inflate(LayoutInflater.java:414) 
            at android.view.LayoutInflater.inflate(LayoutInflater.java:365) 
            at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:378) 
            at android.app.Activity.setContentView(Activity.java:2145) 
            at com.example.adrew.convertmidterm.MainActivity.onCreate(MainActivity.java:14) 
            at android.app.Activity.performCreate(Activity.java:5990) 
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106) 
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278) 
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390) 
            at android.app.ActivityThread.access$800(ActivityThread.java:151) 
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) 
            at android.os.Handler.dispatchMessage(Handler.java:102) 
            at android.os.Looper.loop(Looper.java:135) 
            at android.app.ActivityThread.main(ActivityThread.java:5257) 
            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:903) 
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 
07-09 20:29:02.966 17354-17367/com.example.adrew.convertmidterm W/art﹕ Suspending all threads took: 7.769ms

這裏是我的代碼：

package com.example.adrew.convertmidterm; 

import android.app.Fragment; 
import android.os.Bundle; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.Button; 
import android.widget.EditText; 

import android.view.View.OnClickListener; 

/** 
* A placeholder fragment containing a simple view. 
*/ 
public class MainActivityFragment extends Fragment { 

public MainActivityFragment() { 
} 

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

    //all test 

    //original three without getView(). 
    //final EditText editCentimeters = (EditText) findViewById(R.id.editCentimeters); 

    final EditText editCentimeters = (EditText) getView().findViewById(R.id.editCentimeters); 

    final EditText editInches = (EditText) getView().findViewById(R.id.editInches); 

    Button buttonConvert = (Button) getView().findViewById(R.id.buttonConvert); 

    //buttonConvert.setOnClickListener(new OnClickListener() { 
     buttonConvert.setOnClickListener(new View.OnClickListener() { 

     @Override 
     public void onClick(View arg0) { 

      double centimeters = Double.valueOf(editCentimeters.getText().toString()); 

      double inches = centimeters * 0.393700787 ; 

      editInches.setText(String.valueOf(inches)); 

     } 
    }); 
    //end test 
    return rootView; 
    } 

}

的AndroidManifest.xml：

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
    package="com.example.adrew.convertmidterm" > 

    <application 
     android:allowBackup="true" 
     android:icon="@mipmap/ic_launcher" 
     android:label="@string/app_name" 
     android:theme="@style/AppTheme" > 
     <activity 
      android:name=".MainActivity" 
      android:label="@string/app_name" > 
      <intent-filter> 
       <action android:name="android.intent.action.MAIN" /> 

       <category android:name="android.intent.category.LAUNCHER" /> 
      </intent-filter> 
     </activity> 
    </application> 

</manifest>

Fragment_main .xml低於：

<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:paddingLeft="@dimen/activity_horizontal_margin" 
    android:paddingRight="@dimen/activity_horizontal_margin" 
    android:paddingTop="@dimen/activity_vertical_margin" 
    android:paddingBottom="@dimen/activity_vertical_margin" 
    tools:context=".MainActivityFragment"> 



    <TextView 
     android:id="@+id/textCentimeters" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentTop="true" 
     android:layout_marginTop="34dp" 
     android:text="Centimeters:" 
     android:textAppearance="?android:attr/textAppearanceMedium" /> 

    <TextView 
     android:id="@+id/textInches" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_below="@+id/editCentimeters" 
     android:layout_marginTop="40dp" 
     android:layout_toLeftOf="@+id/editCentimeters" 
     android:text="Inches:" 
     android:textAppearance="?android:attr/textAppearanceMedium" /> 

    <EditText 
     android:id="@+id/editInches" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignBottom="@+id/textInches" 
     android:layout_alignParentRight="true" 
     android:ems="10" 
     android:inputType="number" /> 

    <EditText 
     android:id="@+id/editCentimeters" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignBottom="@+id/textCentimeters" 
     android:layout_alignParentRight="true" 
     android:ems="10" 
     android:inputType="number" /> 

    <Button 
     android:id="@+id/buttonConvert" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_centerHorizontal="true" 
     android:layout_centerVertical="true" 
     android:text="Convert" /> 

</RelativeLayout>

來源

2015-07-10 Drew

你能後的XML？ –

問題可能在xml文件中，所以請添加它 –

我已經添加了androidmanifest.xml。這是我需要補充的嗎？ – Drew

您不能使用getView()作爲參考，因爲您的View將在return rootView;中創建。

return rootView;是在您致電getView()之後。你得到NullPointerException，因爲它尚未創建。

您需要更改

final EditText editCentimeters = (EditText) getView().findViewById(R.id.editCentimeters); 

final EditText editInches = (EditText) getView().findViewById(R.id.editInches); 

Button buttonConvert = (Button) getView().findViewById(R.id.buttonConvert);

到

final EditText editCentimeters = (EditText) rootView.findViewById(R.id.editCentimeters); 

final EditText editInches = (EditText) rootView.findViewById(R.id.editInches); 

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

來源

2015-07-10 00:48:48

謝謝你的工作！非常感謝您的時間 – Drew

當您的問題解決後，在回答時標記「打勾」。 –

已經做了，只好等幾分鐘 – Drew

爲什麼我的應用在模擬器運行後仍然崩潰？

回答

相關問題