单击AlertDialog在Firebase数据库上设置值时出错

Question

我试图在AlertDialog中选择一个选项，但显示错误。 下面是错误：

10-17 00:54:44.765 25600-25600/com.example.jingwen.bluetoothlowenergy E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.jingwen.bluetoothlowenergy, PID: 25600
java.lang.IndexOutOfBoundsException: Invalid index 1, size is 0
at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
at java.util.ArrayList.get(ArrayList.java:308)
at com.example.jingwen.bluetoothlowenergy.MainActivity$1$1.onClick(MainActivity.java:325)
at android.support.v7.app.AlertController$AlertParams$3.onItemClick(AlertController.java:959)
at android.widget.AdapterView.performItemClick(AdapterView.java:300)
at android.widget.AbsListView.performItemClick(AbsListView.java:1143)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:3063)
at android.widget.AbsListView$3.run(AbsListView.java:3881)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5237)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:912)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:707)

这是发生错误的代码，特别是Firebase数据库的setValue部分：

 private void alertdialog() { final CharSequence peers[] = new CharSequence[] {"Home", "School", "Children"}; stopScan(); final String uid = firebaseAuth.getCurrentUser().getUid(); if(alert11!=null && alert11.isShowing()) return; AlertDialog.Builder builder1 = new AlertDialog.Builder(this); builder1.setMessage("Add this device to peer list?"); builder1.setCancelable(true); builder1.setNegativeButton( "Yes", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int id) { AlertDialog.Builder pbuilder = new AlertDialog.Builder(MainActivity.this); pbuilder.setTitle("Set peer as:"); pbuilder.setCancelable(false); pbuilder.setItems(peers, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // the user clicked on option[which] if(which == 0) { databaseRef.child("users").child(uid).child("Peer list").child(mBTDevicesArrayList.get(post).getAddress()).setValue("Home"); Toast.makeText(MainActivity.this,"Set peer as 'Home'",Toast.LENGTH_SHORT).show(); Toast.makeText(MainActivity.this,"Peer list updated!",Toast.LENGTH_SHORT).show(); } if(which == 1) { databaseRef.child("users").child(uid).child("Peer list").child(mBTDevicesArrayList.get(post).getAddress()).setValue("School"); Toast.makeText(MainActivity.this,"Set peer as 'School'",Toast.LENGTH_SHORT).show(); Toast.makeText(MainActivity.this,"Peer list updated!",Toast.LENGTH_SHORT).show(); } if(which == 2) { databaseRef.child("users").child(uid).child("Peer list").child(mBTDevicesArrayList.get(post).getAddress()).setValue("Children"); Toast.makeText(MainActivity.this,"Set peer as 'Children'",Toast.LENGTH_SHORT).show(); Toast.makeText(MainActivity.this,"Peer list updated!",Toast.LENGTH_SHORT).show(); } } }); pbuilder.show(); } }); 

告诉我是否需要显示更多代码。

Answer 1

这可能与Firebase无关。

据我所知，mBTDevicesArrayList（上面未显示定义和赋值）是一个大小为零的ArrayList，并且您正在向其get方法传递值1，如错误消息“ java.lang.IndexOutOfBoundsException”所示：无效的索引1，大小为0“。 堆栈跟踪中的行号将帮助您确定要显示的三个实例之一。