Question

我试图在android中以编程方式激活蓝牙并且应用程序安装正常，但是当我单击按钮激活BT时，它会给出异常。我无法处理异常。任何帮助是极大的赞赏。我是新来的。这是代码：

package com.example.helloandroid2;


import java.io.IOException;

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class HelloAndroid extends Activity {
 // Declare our Views, so we can access them later

 private Button activate_buletooth;
    static final int REQUEST_ENABLE_BT = 0;
    Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
    BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Set Activity Layout
        setContentView(R.layout.main);

         activate_buletooth = (Button)findViewById(R.id.activate_buletooth);

        // Set Click Listener

            activate_buletooth.setOnClickListener(new OnClickListener() {
         @Override
         public void onClick(View v){
          if (mBluetoothAdapter == null) {
              // Device does not support Bluetooth
           Context context = getApplicationContext();
           CharSequence text = "BT not suported";
           int duration = Toast.LENGTH_SHORT;

           Toast toast = Toast.makeText(context, text, duration);
           toast.show();
          }     
          if (!mBluetoothAdapter.isEnabled()) {
              Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
              startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
          }

          // startActivityForResult(discoverableIntent, REQUEST_ENABLE_BT);

         }
        });

    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data)
    {
     if(requestCode == REQUEST_ENABLE_BT)
        {
      if(resultCode == RESULT_CANCELED)
            {
       Context context = getApplicationContext();
       CharSequence text = "bt not available";
       int duration = Toast.LENGTH_SHORT;

       Toast toast = Toast.makeText(context, text, duration);
       toast.show();
            }
       else
             {

             }
        }
    }
}

Answer 1

这是由于默认适配器启用蓝牙所需的时间。我遇到了同样的问题，我追查了它。

在适配器切换蓝牙之前执行此onClick()事件后，预计将“执行”的代码。可能有一个解决方案，比如有一个循环，在蓝牙完全打开之前不允许进一步的代码执行。要么可以有setDelay()种方法可以提供帮助。

欢迎任何进一步的帮助。

android蓝牙激活错误

1 个答案: