我正在尝试以意图开始活动，但活动无法启动。
这是我得到的错误：
06-09 10:32:16.031 28535-28535/com.fluffyclouds.satroots E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.fluffyclouds.satroots, PID: 28535
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.fluffyclouds.satroots/com.fluffyclouds.satroots.AfterSessionActivity}: java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5422)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
at java.util.ArrayList.set(ArrayList.java:481)
at com.fluffyclouds.satroots.AfterSessionActivity.onCreate(AfterSessionActivity.java:81)
at android.app.Activity.performCreate(Activity.java:6251)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5422)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
我发现了这样的多个帖子，但答案要么不适用于我，要么似乎不起作用。
这是我的清单：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.fluffyclouds.satroots">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity
android:name=".StartActivity"
android:label="@string/app_name"
android:theme="@style/AppTheme">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".SessionActivity"
android:label="@string/title_activity_session"
android:theme="@style/AppTheme" />
<activity
android:name=".AfterSessionActivity"
android:label="End Report"
android:theme="@style/AppTheme">
</activity>
</application>
以下是启动意图的初始活动的一部分：
Intent intent=new Intent(SessionActivity.this, AfterSessionActivity.class);
/*intent.putExtra("FILE_NAME", filename);*/
startActivity(intent);
这是第二个应该由意图启动但从未启动的活动：
package com.fluffyclouds.satroots;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.widget.TextView;
import android.widget.Toast;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
public class AfterSessionActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
int numberOfQuestions; //number of questions answered is the same as the number of questions that get asked.
//it gets set in the onCreate and an int is pulled from the integers xml file
ArrayList < String > numberDateSet = new ArrayList < String > ();
ArrayList < String > numberCorrectSet = new ArrayList < String > ();
ArrayList < String > numberIncorrectSet = new ArrayList < String > ();
ArrayList < String > numberAccuracySet = new ArrayList < String > ();
@Override
protected void onCreate(Bundle savedInstanceState) {
//sliding in animation
overridePendingTransition(R.anim.slide_in, R.anim.slide_out);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_after_session);
numberOfQuestions = getResources().getInteger(R.integer.numberOfQuestions);
/*Bundle extras= getIntent().getExtras();
if(extras!=null){
filename=extras.getString("FILE_NAME");
}*/
numberDateSet.add("5/12/2015");
numberCorrectSet.add("3");
/*File progressReport=new File(getFilesDir()+"/"+"progress_file.txt");
try {
BufferedReader br=new BufferedReader(new FileReader(progressReport));
String line;
int i=0;
while ((line=br.readLine())!=null) {//this will populate the date and numberCorrect ArrayLists instantiated earlier
if (i % 2 == 0) {
numberDateSet.add(line);
System.out.println("added line to numberDateSet");
} else {
numberCorrectSet.add(line);
System.out.println("added line to numberCorrectSet");
}
i++;
}
br.close();
} catch (Exception e) {
Toast.makeText(getApplicationContext(), "Unable to retrieve previous data", Toast.LENGTH_SHORT);
}*/
//necessary to reverse the arraylists so they can be listed on cardviews in the appropriate order (most recent at the top)
Collections.reverse(numberDateSet);
Collections.reverse(numberCorrectSet);
for (int i = 0; i < numberCorrectSet.size(); i++) {
numberIncorrectSet.set(i, (numberOfQuestions - Integer.parseInt(numberCorrectSet.get(i))) + "");
int accuracy = numberOfQuestions / (Integer.parseInt(numberCorrectSet.get(i)));
numberAccuracySet.set(i, (accuracy * 100) + "");
}
mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);
mRecyclerView.setHasFixedSize(true);
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);
mAdapter = new MyAdapter(numberDateSet, numberCorrectSet, numberIncorrectSet, numberAccuracySet);
mRecyclerView.setAdapter(mAdapter);
}
@Override
public void onBackPressed() {
Intent intent = new Intent(AfterSessionActivity.this, StartActivity.class);
startActivity(intent);
}
}
这是第二个活动的xml：
<?xml version="1.0" encoding="utf-8"?>
<GridLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="center|top"
android:columnCount="1"
>
<android.support.v7.widget.RecyclerView
android:id="@+id/my_recycler_view"
android:scrollbars="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</GridLayout>
提前致谢
答案 0 :(得分：0)
Caused by: java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
.
.
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at com.fluffyclouds.satroots.AfterSessionActivity.onCreate(AfterSessionActivity.java:81)
我认为这一行是：
numberIncorrectSet.set(i, (numberOfQuestions - Integer.parseInt(numberCorrectSet.get(i))) + "");
该代码将失败，因为代码中此时numberIncorrectSet是一个空列表。