我正在尝试使用Spinner选择用户名，然后在客户端点击开始聊天按钮时打开新的会话布局。我确信按钮代码是正确的，但我的微调器导致我的应用程序崩溃。
myListView.setOnItemSelectedListener(new OnItemSelectedListener () {
@Override
public void onItemSelected(AdapterView<?> parent, View view,
int pos, long id) {
// An item was selected. You can retrieve the selected item using
name1 = parent.getItemAtPosition(pos).toString();
CStart = (Button) findViewById(R.id.Start) ;
CStart.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
open(v);
}
});
}
public void onNothingSelected(AdapterView<?> parent) {
// Another interface callback
}
});
开放方法：
protected void open(View v) {
Intent i = new Intent(this, MainActivity2.class);
i.putExtra("message", name1);
startActivityForResult(i, 1);
}
你能帮我修改一下我的代码吗？
Logcat：
03-24 19:48:32.967: E/AndroidRuntime(23058): FATAL EXCEPTION: main
03-24 19:48:32.967: E/AndroidRuntime(23058): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.javachat/com.example.javachat.MainActivity}: java.lang.IllegalArgumentException: Receiver not registered: com.example.javachat.MainActivity$1@418afa30
03-24 19:48:32.967: E/AndroidRuntime(23058):at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2343)
03-24 19:48:32.967: E/AndroidRuntime(23058):at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2395)
03-24 19:48:32.967: E/AndroidRuntime(23058):at android.app.ActivityThread.access$600(ActivityThread.java:162)
03-24 19:48:32.967: E/AndroidRuntime(23058):at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1364)
03-24 19:48:32.967: E/AndroidRuntime(23058):at android.os.Handler.dispatchMessage(Handler.java:107)
03-24 19:48:32.967: E/AndroidRuntime(23058):at android.os.Looper.loop(Looper.java:194)
03-24 19:48:32.967: E/AndroidRuntime(23058):at android.app.ActivityThread.main(ActivityThread.java:5371)
03-24 19:48:32.967: E/AndroidRuntime(23058):at java.lang.reflect.Method.invokeNative(Native Method)
03-24 19:48:32.967: E/AndroidRuntime(23058):at java.lang.reflect.Method.invoke(Method.java:525)
03-24 19:48:32.967: E/AndroidRuntime(23058):at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833) 03-24 19:48:32.967: E/AndroidRuntime(23058):at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
03-24 19:48:32.967: E/AndroidRuntime(23058):at dalvik.system.NativeStart.main(Native Method)
03-24 19:48:32.967: E/AndroidRuntime(23058): Caused by: java.lang.IllegalArgumentException: Receiver not registered: com.example.javachat.MainActivity$1@418afa30
03-24 19:48:32.967: E/AndroidRuntime(23058):at android.app.LoadedApk.forgetReceiverDispatcher(LoadedApk.java:657)
03-24 19:48:32.967: E/AndroidRuntime(23058):at android.app.ContextImpl.unregisterReceiver(ContextImpl.java:1442)
03-24 19:48:32.967: E/AndroidRuntime(23058):at android.content.ContextWrapper.unregisterReceiver(ContextWrapper.java:445) 03-24 19:48:32.967: E/AndroidRuntime(23058): at com.example.javachat.MainActivity.onDestroy(MainActivity.java:229)
03-24 19:48:32.967: E/AndroidRuntime(23058):at com.example.javachat.MainActivity.onCreate(MainActivity.java:136)
03-24 19:48:32.967: E/AndroidRuntime(23058):at android.app.Activity.performCreate(Activity.java:5122)
03-24 19:48:32.967: E/AndroidRuntime(23058):at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1084)
03-24 19:48:32.967: E/AndroidRuntime(23058):at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2307)
03-24 19:48:32.967: E/AndroidRuntime(23058):... 11 more
清单代码：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.javachat"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="14"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
<application
android:allowBackup="true"
android:icon="@drawable/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>
<activity android:name=".MainActivity2" />
</application>
</manifest>
我的.java文件，如果您需要检查其他任何东西，如导入和方法......
package com.example.javachat;
import java.util.Set;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
private static final int REQUEST_ENABLE_BT = 1;
private Button onBtn;
private Button offBtn;
private Button listBtn;
private Button findBtn;
private TextView text;
private Button CStart ;
private String name1 ;
private BluetoothAdapter myBluetoothAdapter;
private Set<BluetoothDevice> pairedDevices;
private Spinner myListView;
private ArrayAdapter<String> BTArrayAdapter;
//*******************************MAIN************************
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
// take an instance of BluetoothAdapter - Bluetooth radio
myBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if(myBluetoothAdapter == null) {
onBtn.setEnabled(false);
offBtn.setEnabled(false);
listBtn.setEnabled(false);
findBtn.setEnabled(false);
CStart.setEnabled(false);
text.setText("Status: not supported");
Toast.makeText(getApplicationContext(),"Your device does not support Bluetooth",
Toast.LENGTH_LONG).show();
} else {
text = (TextView) findViewById(R.id.text);
onBtn = (Button)findViewById(R.id.turnOn);
onBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
on(v);
}
});
offBtn = (Button)findViewById(R.id.turnOff);
offBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
off(v);
}
});
//*********************************************************
listBtn = (Button)findViewById(R.id.paired);
listBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
list(v);
}
});
//**********************************************************
myListView.setOnItemSelectedListener(new OnItemSelectedListener (){
@Override
public void onItemSelected(AdapterView<?> parent, View view,
int pos, long id) {
// An item was selected. You can retrieve the selected item using
name1= new String (parent.getItemAtPosition(pos).toString());
CStart = (Button) findViewById(R.id.Start) ;
CStart.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
open(v);
}
});
}
public void onNothingSelected(AdapterView<?> parent) {
// Another interface callback
Toast.makeText(getApplicationContext(),"Select a device" ,
Toast.LENGTH_LONG).show();
}
});
//***********************************************************
findBtn = (Button)findViewById(R.id.search);
findBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
find(v);
}
});
//***********************************************************
myListView = (Spinner)findViewById(R.id.listView1);
// create the arrayAdapter that contains the BTDevices, and set it to the ListView
BTArrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item);
BTArrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
myListView.setAdapter(BTArrayAdapter);
}
}
//**********************************METHODE***********************
protected void open(View v) {
// TODO Auto-generated method stub
Intent i = new Intent(this ,MainActivity2.class);
// i.putExtra("message",name1);
startActivityForResult(i, 1);
}
public void on(View view){
if (!myBluetoothAdapter.isEnabled()) {
Intent turnOnIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(turnOnIntent, REQUEST_ENABLE_BT);
Toast.makeText(getApplicationContext(),"Bluetooth turned on" ,
Toast.LENGTH_LONG).show();
}
else{
Toast.makeText(getApplicationContext(),"Bluetooth is already on",
Toast.LENGTH_LONG).show();
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
if(requestCode == REQUEST_ENABLE_BT){
if(myBluetoothAdapter.isEnabled()) {
text.setText("Status: Enabled");
} else {
text.setText("Status: Disabled");
}
}
}
public void list(View view){
// get paired devices
pairedDevices = myBluetoothAdapter.getBondedDevices();
// put it's one to the adapter
for(BluetoothDevice device : pairedDevices)
BTArrayAdapter.add(device.getName()+ "\n" + device.getAddress());
Toast.makeText(getApplicationContext(),"Show Paired Devices",
Toast.LENGTH_SHORT).show();
}
final BroadcastReceiver bReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
// When discovery finds a device
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
// Get the BluetoothDevice object from the Intent
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
// add the name and the MAC address of the object to the arrayAdapter
BTArrayAdapter.add(device.getName() + "\n" + device.getAddress());
BTArrayAdapter.notifyDataSetChanged();
}
}
};
public void find(View view) {
if (myBluetoothAdapter.isDiscovering()) {
// the button is pressed when it discovers, so cancel the discovery
myBluetoothAdapter.cancelDiscovery();
}
else {
BTArrayAdapter.clear();
myBluetoothAdapter.startDiscovery();
registerReceiver(bReceiver, new IntentFilter(BluetoothDevice.ACTION_FOUND));
}
}
public void off(View view){
myBluetoothAdapter.disable();
text.setText("Status: Disconnected");
Toast.makeText(getApplicationContext(),"Bluetooth turned off",
Toast.LENGTH_LONG).show();
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
unregisterReceiver(bReceiver);
}
}
答案 0 :(得分：0)
例外明确说明如下：
Receiver not registered: com.example.javachat.MainActivity$1@418afa30
崩溃发生在这里：
03-24 19:48:32.967: E/AndroidRuntime(23058):at android.content.ContextWrapper.unregisterReceiver(ContextWrapper.java:445)
03-24 19:48:32.967: E/AndroidRuntime(23058): at com.example.javachat.MainActivity.onDestroy(MainActivity.java:229)
03-24 19:48:32.967: E/AndroidRuntime(23058):at com.example.javachat.MainActivity.onCreate(MainActivity.java:136)
unregisterReceiver您有onDestroy，但您没有注册的位置。您还希望看一下here，因为onItemSelected将在没有用户操作的情况下调用Spinner。
但这不是结束。 BroadcastReceiver声明是错误的。由于您在本地使用广播接收器，将其绑定到Activity生命周期，您应该使用LocalBroadcastManager来注册/取消注册onCreate / onDestroy（或其他生命周期回调，取决于你的需要）。因此，清单中的以下声明毫无意义：
<receiver android:name=".bReceiver">
</receiver>
因为你没有名为bReceiver的类，所以你有一个局部变量（应该实际上是一个类成员）bReceiver，它指向BroadcastReceiver类的实例。< / p>
答案 1 :(得分：-1)
如果点击按钮导致崩溃，那么原因是 -
您已在onItemSlected（）中将方法本地匿名内部类对象设置为侦听器。方法执行完成后，该对象将被销毁。
因此，当onItemSelected完成时，您的侦听器对象已正确设置。但是当点击按钮时，调用保存的侦听器对象，实际上是由垃圾收集器清除。
你不应该这样设置监听器。如果我正确理解了您的要求，您可以轻松地在项目点击监听器之外设置监听器。