所以我正在建立一个关于事实的应用程序。我为不同的活动创建了不同的按钮,我在textview中显示了我的事实。我已经从选择事实的资产中创建了不同的文本文件。问题是每次我点击按钮我的应用程序崩溃。帮帮我们......
我的xml代码
<TextView android:text="@string/hello_world" android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:id="@+id/n"
android:layout_centerHorizontal="true"
android:textSize="35dp" />
<ImageButton
android:layout_width="80dp"
android:layout_height="80dp"
android:id="@+id/btn"
android:background="@drawable/boombuttonnext"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true" />
<ImageButton
android:layout_width="80dp"
android:layout_height="80dp"
android:id="@+id/prev"
android:background="@drawable/backk"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
我的Java代码
public class MainActivity22Activity extends AppCompatActivity {
ImageButton btn,prev;
TextView tc;
ArrayList<String> listOfFacts;
int position = 0;
void init()
{
listOfFacts = new ArrayList<String>();
try {
InputStream is = getAssets().open("boom.txt");
BufferedReader in = new BufferedReader(new InputStreamReader(is));
String line ;
while( (line = in.readLine()) != null)
listOfFacts.add(line);
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init();
position = getSharedPreferences("storage" ,1).getInt("pos",0);
btn = (ImageButton) findViewById(R.id.btn);
prev = (ImageButton) findViewById(R.id.prev);
tc = (TextView) findViewById(R.id.b);
tc.setText("" + listOfFacts.get(position));
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
position++;
if(listOfFacts.size()==position)
position = 0;
tc.setText("" + listOfFacts.get(position));
}
});
prev.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
position--;
if(position<0)
position = listOfFacts.size()-1;
tc.setText("" + listOfFacts.get(position));
}
});
}
@Override
protected void onPause() {
super.onPause();
getSharedPreferences("storage" ,1).edit().putInt("pos" , position).commit();
}
}
答案 0 :(得分:0)
从logcat的输出中,访问阵列时出现问题。确保从数组中获取元素的索引不会超出边界。
&GT; at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)at java.util.ArrayList.get(ArrayList.java:308)at bollywoodfacts.checkinglist.MainActivity2Activity.onCreate(MainActivity2Activity .java:63)at android.app .Activity.performCreate(Activity.java:5937)在android.app.Anstrumentation.caread.nleCreate(Instrumentation.java:1105)android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)android.app.ActivityThread.handleLaunchActivity的android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105) ActivityThread.java:2360)
tc.setText("" + listOfFacts.get(position));