【发布时间】:2016-04-04 02:24:51
【问题描述】:
我知道之前有人询问过其他程序,但我的程序仍然收到下面给出的错误
线程 [Thread-15956](暂停(异常 ViewRootImpl$CalledFromWrongThreadException))
请帮忙!!
这是我的 MainActivity 类
package a.example.na;
import java.util.Scanner;
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.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
public class MainActivity extends Activity {
private static TextView inputtext;
private BluetoothAdapter myBluetoothAdapter;
private Set<BluetoothDevice> pairedDevices;
private ListView myListView;
private ArrayAdapter<String> BTArrayAdapter;
private BluetoothDevice mDevice;
private Button findBtn;
private String address;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if(myBluetoothAdapter == null) {
findBtn.setEnabled(false);
Toast.makeText(getApplicationContext(),"Your device does not support Bluetooth",
Toast.LENGTH_LONG).show();
} else {
inputtext = (TextView) findViewById(R.id.text);
findBtn = (Button)findViewById(R.id.search);
findBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
find(v);
}
});
myListView = (ListView)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_list_item_1);
myListView.setAdapter(BTArrayAdapter);
myListView.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> adapterView, View v, int pos,
long arg3) {
// Add the name and address to an array adapter to show in a ListView
String i = (String) adapterView.getItemAtPosition(pos);
B b=new B(inputtext);
b.start();
Scanner scanner = new Scanner(i);
if(scanner.hasNextLine()) {
address =scanner.nextLine();
}
mDevice = myBluetoothAdapter.getRemoteDevice(address);
scanner.close();
}
});
}
}
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.getAddress()+ "\n" +device.getName() );
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));
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.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();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
unregisterReceiver(bReceiver);
}
}
这是我单独的线程类
package com.bt;
import android.widget.TextView;
public class B extends Thread {
TextView inputtext;
public B(TextView x){
inputtext=x;
}
public void run(){
inputtext.setText("hero");
}
}
【问题讨论】:
-
你不能从主线程以外的线程调用
.setText()。
标签: java android multithreading