Question

我想将bT模块连接到我的Android手机。但是当我运行我的代码时，这个错误就来了我/编舞：跳过了439帧！应用程序可能在其主线程上做了太多工作。

package com.example.hp.classcircuit;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothManager;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Build;
import android.support.annotation.RequiresApi;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Set;
import java.util.UUID;

public class MainActivity extends AppCompatActivity {
//decleare valiables
BluetoothAdapter mBluetoothAdapter;
BluetoothDevice mDevice;
ListView listView;
ConnectThread mConnectThread;
ArrayList pdal;
String DEVICE_ADDRESS;
boolean found=false;
BluetoothManager BM;
Set<BluetoothDevice> pairedDevices;

@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)//for chacking sutable 
 //API
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    listView= (ListView) findViewById(R.id.listview);//Listview in xml
    //call BT Manager
    BM= (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
    //call BT Adaptor
    mBluetoothAdapter=BM.getAdapter();
    //call paired device
    pairedDevices = mBluetoothAdapter.getBondedDevices();

    if (mBluetoothAdapter == null) {
        // Device does not support Bluetooth
        Toast.makeText(MainActivity.this, "Device not support bluetooth", Toast.LENGTH_LONG).show();
    }
   //check BT is on or off
        if (!mBluetoothAdapter.isEnabled()) {
            Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableBtIntent, 1);
        }

    pdal=new ArrayList();

    if (pairedDevices.size() > 0) {
        for (BluetoothDevice device : pairedDevices) {
            pdal.add(device.getName());

        }

        ArrayAdapter pda=new ArrayAdapter(this, android.R.layout.simple_list_item_1,pdal);

        listView.setAdapter(pda);
    }
    listView.setOnItemClickListener(myListClickListener);


}

**

//动作点击listnor for listview

private AdapterView.OnItemClickListener myListClickListener = new AdapterView.OnItemClickListener() {


    @Override
    public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
        String DeviceName=pdal.get(i).toString();
        for(BluetoothDevice device : pairedDevices)
        {
            if(device.getName().equals(DeviceName)) {

                DEVICE_ADDRESS=device.getAddress();
                Log.i(device.getName(), DEVICE_ADDRESS);

                mDevice=device;

                found=true;

                break;
            }
        }
        mConnectThread = new ConnectThread(mDevice);
        //call the inner class method
        mConnectThread.doInBackground();
    }
};

//内部课程

public class ConnectThread extends AsyncTask<String, Integer, Long>  {
    private final BluetoothSocket mmSocket;
    private final BluetoothDevice mmDevice;
    private final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb");
    //constructor of inner class
    public ConnectThread(BluetoothDevice device) {
        BluetoothSocket tmp = null;
        mmDevice = device;
        try {
            tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
        } catch (IOException e) { }
        mmSocket = tmp;
    }

     //override the methode
    protected Long doInBackground(String... strings) {
        mBluetoothAdapter.cancelDiscovery();
        try {
            mmSocket.connect();
            Log.i("Status","connected");
        } catch (IOException connectException) {
            try {
                mmSocket.close();
            } catch (IOException closeException) { }
            return null;
        }
        return null;
    }

    //function for close the socket
    public void close() {
        try {
            mmSocket.close();
        } catch (IOException e) { }
    }
}

}

以上是我的异步课。我没有发现错误，请指导我错误的地方。感谢所有

Answer 1

不要打电话

mConnectThread.doInBackground();

你所做的只是破坏了AsyncTask的概念，并完成了UI线程上的所有工作。

线程规则

此类必须遵循一些线程规则   正常工作：


必须在UI线程上加载AsyncTask类。这是从JELLY_BEAN开始自动完成的。

必须在UI线程上创建任务实例。
  必须在UI线程上调用
execute（Params ...）。

不调用 onPreExecute（），onPostExecute（Result）， doInBackground（参数...），onProgressUpdate（进度...）手动

任务只能执行一次（如果尝试第二次执行，则会抛出异常。）

必须使用AsyncTask调用
execute()。所以将上面的行改为：

mConnectThread.execute();

请注意您定义ConnectThread预期某些String参数 - extends AsyncTask<String, Integer, Long>的方式，但您从未在代码中使用此类参数。这些参数可以作为execute(String ... params)方法中的参数传递。最好将签名更改为：

public class ConnectThread extends AsyncTask<Void, Integer, Long> { protected Long doInBackground(Void... params) { //your code here } }

I / Choreographer：跳过439帧！应用程序可能在其主线程上做了太多工作

1 个答案: