应用程序崩溃的原因尺蠖。prepare（）在beginlistendata（）函数 [英] App crashed due to looper.prepare() in the beginlistendata() function
本文介绍了应用程序崩溃的原因尺蠖。prepare（）在beginlistendata（）函数的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
公共类BluetoothActivity延伸活动{//创建ACTION_FOUND一个BroadcastReceiver
私人最终广播接收器广播接收器=新的广播接收器（）{
公共无效的onReceive（上下文的背景下，意图意图）{
字符串行动= intent.getAction（）;
//每当远程蓝牙设备发现
如果（BluetoothDevice.ACTION_FOUND.equals（动作））{
//从意向获取BluetoothDevice类对象
BluetoothDevice类BluetoothDevice类= intent.getParcelableExtra（BluetoothDevice.EXTRA_DEVICE）;
//添加名称和地址到一个数组适配器在ListView显示
adapter.add（bluetoothDevice.getName（）+\\ n
+ bluetoothDevice.getAddress（））;
}
}
};
//宣言
TextView的myLabel;
螺纹的WorkerThread;
字节[] readBuffer;
INT readBufferPosition;
挥发性布尔stopWorker;
私人BluetoothAdapter mBluetoothAdapter;
私人的ListView列表视图;
私人ArrayAdapter适配器;
私人切换按钮切换按钮;
私有静态最终诠释REQUEST_ENABLE_BT = 0;
私有静态最终诠释DISCOVERABLE_DURATION = 0;
私有静态最终诠释DISCOVERABLE_BT_REQUEST_ code = 2;
@覆盖
保护无效的onCreate（捆绑savedInstanceState）{
super.onCreate（savedInstanceState）;
的setContentView（R.layout.bluetooth_main）;
切换按钮=（切换按钮）findViewById（R.id.toggleButton）;
列表视图=（ListView控件）findViewById（R.id.listView）;
// ListView项点击监听器
listview.setOnItemClickListener（新AdapterView.OnItemClickListener（）{
@覆盖
公共无效onItemClick（适配器视图＆LT;＆GT;母公司，观景，
INT位置，长的id）{
// ListView中单击项目价值
字符串itemValue =（字符串）listview.getItemAtPosition（位置）;
Toast.makeText（getApplicationContext（），点击，Toast.LENGTH_LONG）.show（）;
字符串MAC = itemValue.substring（itemValue.length（） - 17）;
BluetoothDevice类BluetoothDevice类= mBluetoothAdapter.getRemoteDevice（MAC）;
//启动在单独的线程的连接请求 ConnectingThread T =新ConnectingThread（BluetoothDevice类）;
t.start（）;
}
}）;
适配器=新ArrayAdapter
（这一点，android.R.layout.simple_list_item_1）;
listview.setAdapter（适配器）; //验证支持蓝牙设备上
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter（）;
//设备不支持蓝牙
如果（mBluetoothAdapter == NULL）{
}
} //结束的OnCreate公共无效onToggle（查看视图）{
adapter.clear（）; 如果（toggleButton.isChecked（））{
//启用蓝牙
如果（！mBluetoothAdapter.isEnabled（））{
意图enableBtIntent =新意图（BluetoothAdapter.ACTION_REQUEST_ENABLE）;
startActivityForResult（enableBtIntent，REQUEST_ENABLE_BT）;
Toast.makeText（getApplicationContext（），变身的，Toast.LENGTH_LONG）.show（）;
}
其他
{
Toast.makeText（getApplicationContext（），已在Toast.LENGTH_LONG）.show（）;
//要发现远程蓝牙设备
discoverDevices（）;
//使本地设备的其他设备发现
makeDiscoverable（）;
}
} //如果1月底 其他{
//关闭蓝牙
mBluetoothAdapter.disable（）;
adapter.clear（）;
Toast.makeText（getApplicationContext（），已关闭，Toast.LENGTH_LONG）.show（）;
}
}公共无效的onActivityResult（INT申请code，INT结果code，意图数据）{
如果（要求code == REQUEST_ENABLE_BT）{
//蓝牙成功启用！
如果（结果code == Activity.RESULT_OK）{
Toast.makeText（getApplicationContext（），蓝牙技术现在已启用，Toast.LENGTH_SHORT）.show（）; //使本地设备的其他设备发现
makeDiscoverable（）;
//要发现远程蓝牙设备
Log.e（calldiscover，FUNC）;
discoverDevices（）;
Log.e（发现，设备）;
//启动一个线程来创建服务器套接字监听
//为连接请求
Log.e（listenthread，listenthread）;
ListeningThread T =新ListeningThread（）;
Log.e（呼，t.start）;
t.start（）;
Log.e（t.start，过）;
}
其他{
// RESULT_CANCELED如用户拒绝
Toast.makeText（getApplicationContext（），未启用蓝牙。
Toast.LENGTH_SHORT）.show（）; //关闭切换按钮
toggleButton.setChecked（假）;
} } //如果1月底
}
保护无效discoverDevices（）{
//要扫描远程蓝牙设备
如果（mBluetoothAdapter.startDiscovery（））{Log.e（盘，打印）;
Toast.makeText（getApplicationContext（），发现其他蓝牙设备......，Toast.LENGTH_SHORT）.show（）;
}
其他{
Log.e（印刷，印刷）;
Toast.makeText（getApplicationContext（），发现无法启动。Toast.LENGTH_SHORT）.show（）;
}
}保护无效makeDiscoverable（）{
//使本地设备可发现
意向discoverableIntent =新
意图（BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE）;
discoverableIntent.putExtra（BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION，DISCOVERABLE_DURATION）;
startActivityForResult（discoverableIntent，DISCOVERABLE_BT_REQUEST_ code）;
}@覆盖
保护无效onResume（）{
super.onResume（）;
//注册ACTION_FOUND的广播接收器
IntentFilter的过滤器=新的IntentFilter（BluetoothDevice.ACTION_FOUND）;
this.registerReceiver（广播接收器，过滤器）;
}@覆盖
保护无效的onPause（）{
super.onPause（）;
this.unregisterReceiver（广播接收器）;
}@覆盖
公共布尔onCreateOptionsMenu（菜单菜单）{
//充气菜单;如果是present这增加了项目操作栏。
。getMenuInflater（）膨胀（R.menu.menu_main，菜单）;
返回true;
}@覆盖
公共布尔onOptionsItemSelected（菜单项项）{
//处理动作栏项目点击这里。操作栏会
//自动处理上点击主页/向上按钮，只要
//你在AndroidManifest.xml中指定一个父活动。
INT ID = item.getItemId（）; // noinspection SimplifiableIfStatement
如果（ID == R.id.action_settings）{
返回true;
} 返回super.onOptionsItemSelected（项目）;
}
私有类ListeningThread继承Thread {
私人最终BluetoothServerSocket bluetoothServerSocket; 公共ListeningThread（）{
BluetoothServerSocket温度= NULL;
尝试{
TEMP = mBluetoothAdapter.listenUsingRfcommWithServiceRecord（的getString（R.string.app_name），UUID）; }赶上（IOException异常五）{
e.printStackTrace（）;
}
bluetoothServerSocket =温度;
} 公共无效的run（）{
的BluetoothSocket的BluetoothSocket;
//一边听直到返回的BluetoothSocket这将阻止
//或者发生异常
而（真）{
尝试{
Log.e（外衣，过）;
的BluetoothSocket = bluetoothServerSocket.accept（）;
Log.e（BT，接受）;
}赶上（IOException异常五）{Log.e（错误，抓）;
打破;
}
//如果连接被接受
如果（的BluetoothSocket！= NULL）{
Log.e（连接被接受的，过）;
BluetoothActivity.this.runOnUiThread（新的Runnable（）{ @覆盖
公共无效的run（）{
Toast.makeText（BluetoothActivity.this！连接，Toast.LENGTH_SHORT）.show（）; }
}）; //管理在一个单独的线程连接 尝试{Log.e（callserver，关闭）;
bluetoothServerSocket.close（）;
}赶上（IOException异常五）{
e.printStackTrace（）;
}
打破;
}
} //而结束
} //取消监听套接字，并终止线程
公共无效取消（）{
尝试{Log.e（取消，插座）;
bluetoothServerSocket.close（）;
}赶上（IOException异常五）{
e.printStackTrace（）;
}
}
} //建立一个客户端连接
私有类ConnectingThread继承Thread {
的OutputStream mmOutputStream;
InputStream的mmInputStream;
私人最终的BluetoothSocket的BluetoothSocket;
私人最终BluetoothDevice类BluetoothDevice类; 公共ConnectingThread（BluetoothDevice类设备）{ 温度的BluetoothSocket = NULL;
BluetoothDevice类=设备; //获取的BluetoothSocket与给定的BluetoothDevice类连接
尝试{Log.e（click6，click6）;
TEMP = bluetoothDevice.createRfcommSocketToServiceRecord（UUID）;
}赶上（IOException异常五）{
e.printStackTrace（）;
}
的BluetoothSocket =温度;
} 公共无效的run（）{
//取消任何发现，因为它会连接放缓
Log.e（click7，click7）;
mBluetoothAdapter.cancelDiscovery（）;
Log.e（click8，click8）; 尝试{ //这将阻止，直到它连接到该设备成功
//通过的BluetoothSocket或抛出一个异常
bluetoothSocket.connect（）;
mmOutputStream = bluetoothSocket.getOutputStream（）;
mmInputStream = bluetoothSocket.getInputStream（）;
beginListenForData（）;
Log.e（listendata，lsitendata）;
BluetoothActivity.this.runOnUiThread（新的Runnable（）{ @覆盖
公共无效的run（）{
Toast.makeText（BluetoothActivity.this，跟设备！，Toast.LENGTH_SHORT）.show（）; }
}）;
Log.e（click9，click9）;
}赶上（IOException异常的ConnectException）{
connectException.printStackTrace（）;
尝试{
bluetoothSocket.close（）;
Log.e（click6，blueclose）;
}赶上（IOException异常closeException）{
closeException.printStackTrace（）;
}
}
}
无效beginListenForData（）
{
最后的处理程序处理程序=新的处理程序（）;
最后一个字节的分隔符= 10; //这是ASCII code为一个换行符 stopWorker = FALSE;
readBufferPosition = 0;
readBuffer =新字节[1024]; //它采用了1024字节长缓冲器，因为它不具有知道输入数据流的长度的任何方式。
的WorkerThread =新主题（新的Runnable（）
{
公共无效的run（）
{
而（Thread.currentThread（）isInterrupted（）及！＆放大器;！stopWorker）
{
尝试
{
INT参考bytesAvailable = mmInputStream.available（）;
如果（参考bytesAvailable大于0）
{
字节[] = packetBytes新的字节[方bytesAvailable]
mmInputStream.read（packetBytes）;
的for（int i = 0; I＆LT;方bytesAvailable;我++）
{
字节B = packetBytes [I]
如果（二==分隔符）
{
字节[] EN codedBytes =新的字节[readBufferPosition]
System.arraycopy（readBuffer，0，EN codedBytes，0，EN codedBytes.length）;
最终字符串数据=新的String（EN codedBytes，US-ASCII）;
readBufferPosition = 0; handler.post（新的Runnable（）
{
公共无效的run（）
{ myLabel.setText（数据）;
}
}）; }
其他
{
readBuffer [readBufferPosition ++] = B;
}
}
}
}
赶上（IOException异常前）
{
stopWorker = TRUE;
}
}
}
}）; workerThread.start（）;
}
喜应用程序崩溃时我尝试调用beginListenForData（）;不能内螺纹创建处理程序中的错误状态已经不叫活套。prepare（）
有谁知道自己做错了什么？我是新来的机器人。请帮忙。
在
Bluetooth.xml ＆LT;？XML版本=1.0编码=UTF-8＆GT？;
＆LT;的RelativeLayout的xmlns：机器人=http://schemas.android.com/apk/res/android
的xmlns：工具=http://schemas.android.com/tools
机器人：layout_width =match_parent
机器人：layout_height =match_parent
机器人：paddingLeft =@扪/ activity_horizontal_margin
机器人：paddingRight =@扪/ activity_horizontal_margin
机器人：paddingTop =@扪/ activity_vertical_margin
机器人：paddingBottom会=@扪/ activity_vertical_margin
工具：上下文=BluetoothActivity。＆GT; ＆LT;切换按钮
机器人：layout_width =WRAP_CONTENT
机器人：layout_height =WRAP_CONTENT
机器人：纹元=关闭蓝牙
机器人：textOff =打开蓝牙
机器人：ID =@ + ID /切换按钮
安卓的onClick =onToggle
机器人：layout_alignParentTop =真
机器人：layout_alignParentStart =真/＆GT; ＆LT; ListView控件
机器人：layout_width =WRAP_CONTENT
机器人：layout_height =WRAP_CONTENT
机器人：ID =@ + ID /的ListView
机器人：layout_alignParentStart =真
机器人：layout_marginStart =76dp
机器人：layout_below =@ + ID /切换按钮/＆GT; ＆LT;的TextView
机器人：ID =@ + /标记
机器人：layout_width =FILL_PARENT
机器人：layout_height =WRAP_CONTENT
机器人：文字=请在此处键入
机器人：layout_below =@ + ID /切换按钮
机器人：layout_centerHorizontal =真
机器人：layout_marginTop =66dp/＆GT;
＆LT; / RelativeLayout的＆GT;
解决方案
试试这个里面的 beginListenForData（）
替换
最后的处理程序处理程序=新的处理程序（）;
有了这个
最后的处理程序处理程序=新的处理程序（Looper.getMainLooper（））;
public class BluetoothActivity extends Activity {
// Create a BroadcastReceiver for ACTION_FOUND
private final BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
// Whenever a remote Bluetooth device is found
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
// Get the BluetoothDevice object from the Intent
BluetoothDevice bluetoothDevice = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
// Add the name and address to an array adapter to show in a ListView
adapter.add(bluetoothDevice.getName() + "\n"
+ bluetoothDevice.getAddress());
}
}
};
//declaration
TextView myLabel;
Thread workerThread;
byte[] readBuffer;
int readBufferPosition;
volatile boolean stopWorker;
private BluetoothAdapter mBluetoothAdapter;
private ListView listview;
private ArrayAdapter adapter;
private ToggleButton toggleButton;
private static final int REQUEST_ENABLE_BT =0;
private static final int DISCOVERABLE_DURATION = 0;
private static final int DISCOVERABLE_BT_REQUEST_CODE = 2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.bluetooth_main);
toggleButton = (ToggleButton) findViewById(R.id.toggleButton);
listview = (ListView) findViewById(R.id.listView);
// ListView Item Click Listener
listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// ListView Clicked item value
String itemValue = (String) listview.getItemAtPosition(position);
Toast.makeText(getApplicationContext(), "clicked", Toast.LENGTH_LONG).show();
String MAC = itemValue.substring(itemValue.length() - 17);
BluetoothDevice bluetoothDevice = mBluetoothAdapter.getRemoteDevice(MAC);
// Initiate a connection request in a separate thread
ConnectingThread t = new ConnectingThread(bluetoothDevice);
t.start();
}
});
adapter = new ArrayAdapter
(this,android.R.layout.simple_list_item_1);
listview.setAdapter(adapter);
//verify bluetooth is supported on the device
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
// Device does not support Bluetooth
if (mBluetoothAdapter == null) {
}
}//end oncreate
public void onToggle(View view) {
adapter.clear();
if (toggleButton.isChecked()){
//enable bluetooth
if (!mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
Toast.makeText(getApplicationContext(), "Turned on", Toast.LENGTH_LONG).show();
}
else
{
Toast.makeText(getApplicationContext(),"Already on", Toast.LENGTH_LONG).show();
//To discover remote Bluetooth devices
discoverDevices();
// Make local device discoverable by other devices
makeDiscoverable();
}
}//end of 1st if
else{
//turn off bluetooth
mBluetoothAdapter.disable();
adapter.clear();
Toast.makeText(getApplicationContext(),"Turned off" ,Toast.LENGTH_LONG).show();
}
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_ENABLE_BT) {
// Bluetooth successfully enabled!
if (resultCode == Activity.RESULT_OK) {
Toast.makeText(getApplicationContext(), "Bluetooth is now enabled.",Toast.LENGTH_SHORT).show();
// Make local device discoverable by other devices
makeDiscoverable();
// To discover remote Bluetooth devices
Log.e("calldiscover", "func");
discoverDevices();
Log.e("Discover", "device");
// Start a thread to create a server socket to listen
// for connection request
Log.e("listenthread", "listenthread");
ListeningThread t = new ListeningThread();
Log.e("call", "t.start");
t.start();
Log.e("t.start", "over");
}
else {
// RESULT_CANCELED as user refused
Toast.makeText(getApplicationContext(), "Bluetooth is not enabled.",
Toast.LENGTH_SHORT).show();
// Turn off togglebutton
toggleButton.setChecked(false);
}
}//end of 1st if
}
protected void discoverDevices(){
// To scan for remote Bluetooth devices
if (mBluetoothAdapter.startDiscovery()) {Log.e("disc", "print");
Toast.makeText(getApplicationContext(), "Discovering other bluetooth devices...", Toast.LENGTH_SHORT).show();
}
else {
Log.e("print", "print");
Toast.makeText(getApplicationContext(), "Discovery failed to start.", Toast.LENGTH_SHORT).show();
}
}
protected void makeDiscoverable(){
// Make local device discoverable
Intent discoverableIntent = new
Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, DISCOVERABLE_DURATION);
startActivityForResult(discoverableIntent, DISCOVERABLE_BT_REQUEST_CODE);
}
@Override
protected void onResume() {
super.onResume();
// Register the BroadcastReceiver for ACTION_FOUND
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
this.registerReceiver(broadcastReceiver, filter);
}
@Override
protected void onPause() {
super.onPause();
this.unregisterReceiver(broadcastReceiver);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
private class ListeningThread extends Thread {
private final BluetoothServerSocket bluetoothServerSocket;
public ListeningThread() {
BluetoothServerSocket temp = null;
try {
temp = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(getString(R.string.app_name), uuid);
} catch (IOException e) {
e.printStackTrace();
}
bluetoothServerSocket = temp;
}
public void run() {
BluetoothSocket bluetoothSocket;
// This will block while listening until a BluetoothSocket is returned
// or an exception occurs
while (true) {
try {
Log.e("while", "over");
bluetoothSocket = bluetoothServerSocket.accept();
Log.e("bt", "accept");
} catch (IOException e) {Log.e("error", "catch");
break;
}
// If a connection is accepted
if (bluetoothSocket != null) {
Log.e("connection is accepted", "over");
BluetoothActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(BluetoothActivity.this, "Connected!", Toast.LENGTH_SHORT).show();
}
});
// Manage the connection in a separate thread
try {Log.e("callserver", "close");
bluetoothServerSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
break;
}
}//end of while
}
// Cancel the listening socket and terminate the thread
public void cancel() {
try {Log.e("cancel", "socket");
bluetoothServerSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
//Setting Up a Connecting Client
private class ConnectingThread extends Thread {
OutputStream mmOutputStream;
InputStream mmInputStream;
private final BluetoothSocket bluetoothSocket;
private final BluetoothDevice bluetoothDevice;
public ConnectingThread(BluetoothDevice device) {
BluetoothSocket temp = null;
bluetoothDevice = device;
// Get a BluetoothSocket to connect with the given BluetoothDevice
try { Log.e("click6", "click6");
temp = bluetoothDevice.createRfcommSocketToServiceRecord(uuid);
} catch (IOException e) {
e.printStackTrace();
}
bluetoothSocket = temp;
}
public void run() {
// Cancel any discovery as it will slow down the connection
Log.e("click7", "click7");
mBluetoothAdapter.cancelDiscovery();
Log.e("click8", "click8");
try {
// This will block until it succeeds in connecting to the device
// through the bluetoothSocket or throws an exception
bluetoothSocket.connect();
mmOutputStream = bluetoothSocket.getOutputStream();
mmInputStream = bluetoothSocket.getInputStream();
beginListenForData();
Log.e("listendata", "lsitendata");
BluetoothActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(BluetoothActivity.this, "Connected with Device!", Toast.LENGTH_SHORT).show();
}
});
Log.e("click9", "click9");
} catch (IOException connectException) {
connectException.printStackTrace();
try {
bluetoothSocket.close();
Log.e("click6", "blueclose");
} catch (IOException closeException) {
closeException.printStackTrace();
}
}
}
void beginListenForData()
{
final Handler handler = new Handler();
final byte delimiter = 10; //This is the ASCII code for a newline character
stopWorker = false;
readBufferPosition = 0;
readBuffer = new byte[1024];//It uses a 1024 bytes long buffer because it doesn't have any way of knowing the length of the input stream.
workerThread = new Thread(new Runnable()
{
public void run()
{
while(!Thread.currentThread().isInterrupted() && !stopWorker)
{
try
{
int bytesAvailable = mmInputStream.available();
if(bytesAvailable > 0)
{
byte[] packetBytes = new byte[bytesAvailable];
mmInputStream.read(packetBytes);
for(int i=0;i<bytesAvailable;i++)
{
byte b = packetBytes[i];
if(b == delimiter)
{
byte[] encodedBytes = new byte[readBufferPosition];
System.arraycopy(readBuffer, 0, encodedBytes, 0, encodedBytes.length);
final String data = new String(encodedBytes, "US-ASCII");
readBufferPosition = 0;
handler.post(new Runnable()
{
public void run()
{
myLabel.setText(data);
}
});
}
else
{
readBuffer[readBufferPosition++] = b;
}
}
}
}
catch (IOException ex)
{
stopWorker = true;
}
}
}
});
workerThread.start();
}
Hi the app crashed when I try to call beginListenForData(); The error state that Can't create handler inside thread that has not called Looper.prepare()
Does anyone know what wrong? I am new to android. Please help.
Bluetooth.xml below
<?xml version="1.0" encoding="utf-8"?>
<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=".BluetoothActivity">
<ToggleButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textOn="Turn off Bluetooth"
android:textOff="Turn on Bluetooth"
android:id="@+id/toggleButton"
android:onClick="onToggle"
android:layout_alignParentTop="true"
android:layout_alignParentStart="true" />
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/listView"
android:layout_alignParentStart="true"
android:layout_marginStart="76dp"
android:layout_below="@+id/toggleButton" />
<TextView
android:id="@+id/label"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Type here:"
android:layout_below="@+id/toggleButton"
android:layout_centerHorizontal="true"
android:layout_marginTop="66dp" />
</RelativeLayout>
解决方案
Try this inside beginListenForData()
Replace
final Handler handler = new Handler();
With this
final Handler handler = new Handler(Looper.getMainLooper());
这篇关于应用程序崩溃的原因尺蠖。prepare（）在beginlistendata（）函数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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