Question

我正在为英飞凌XMC4500微处理器编写嵌入式应用程序。我从不同的传感器读取数据，我通过蓝牙模块发送这些数据，以便在Android smarphone的屏幕上显示它们。我使用GraphView库。

我根据Android教程实现了BluetoothClass。如果我从单个传感器获取数据，那么一切都很好。但是当我从多个传感器获取数据时，我的应用程序无法顺利运行。

当然我在单独的线程中进行蓝牙连接，我尝试在Handler中更新UI。请告诉我，我做错了什么。当然，我通过JSON交换格式发送数据：

我从微控制器方面发送了类似的东西：

        sprintf(json_data, "{"
                            "\"m\":"
                            "["
                                    "{"
                                        "\"id\":a,"
                                        "\"x\":%.2f,"
                                        "\"y\":%.2f,"
                                        "\"z\":%.2f"
                                    "},"
                                    "{"
                                        "\"id\":g,"
                                        "\"x\":%.2f,"
                                        "\"y\":%.2f,"
                                        "\"z\":%.2f"
                                    "},"
                                    "{"
                                        "\"id\":m,"
                                        "\"x\":%.2f,"
                                        "\"y\":%.2f,"
                                        "\"z\":%.2f"
                                    "},"
                                    "{"
                                        "\"id\":t,"
                                        "\"x\":%.2f"
                                    "},"
                                    "{"
                                        "\"id\":h,"
                                        "\"x\":%.2f"
                                    "}"
                            "]"
                        "}", getAccelXf(), getAccelYf(), getAccelZf(), getGyroXf(), getGyroYf(), getGyroZf(), getMagnetXf(), getMagnetYf(), getMagnetZf(), readTemperature(), readHumidity());

作为我的请求的附件，我添加了一些源代码：

    public class ConnectedThread extends Thread
{
    BluetoothSocket connectedSocket;
    InputStream inStream;
    OutputStream outStream;

    public ConnectedThread(BluetoothSocket socket)
    {
        connectedSocket = socket;
        InputStream tmpIn = null;
        OutputStream tmpOut = null;



        try
        {

            if (connectedSocket != null)
            {
                tmpIn = connectedSocket.getInputStream();
                tmpOut = connectedSocket.getOutputStream();
                mHandler.obtainMessage(Constants.MESSAGE_DEVICE_CONNECTED_SUCCESSFULLY).sendToTarget();
               // Toast.makeText(activityContext, "connectedSocket != null", Toast.LENGTH_LONG);
            }
        }
        catch (IOException e) {
            mHandler.obtainMessage(Constants.MESSAGE_INPUT_OUTPUT_STREAM_UNAVAILABLE).sendToTarget();
            e.printStackTrace();
        }

        inStream = tmpIn;
        outStream = tmpOut;
    }

    public void run()
    {

        if(bluetoothAdapter.isDiscovering()){
            bluetoothAdapter.cancelDiscovery();
        }

        byte[] buffer = new byte[4096];
        int bytes;

        String dupa;

        while (true)
        {
            try {
                if (inStream != null)
                {
                    bytes = inStream.available();

                    if(bytes > 0 && bytes <= 200)
                    {
                        byte[] pocketBytes = new byte[bytes];
                        inStream.read(pocketBytes);
                        //Log.d(TAG, "setState() " + mState + " -> " + state);
                        System.out.println(pocketBytes.toString());
                        dupa = pocketBytes.toString();
                        System.out.println(dupa);

                        mHandler.obtainMessage(MESSAGE_READ, bytes, -1, pocketBytes).sendToTarget();
                    }
                }
            } catch (IOException e) {
                mHandler.obtainMessage(Constants.MESSAGE_REMOTE_DEV_DISCONNECTED).sendToTarget();
                break;
            }

            /*try
            {
                Thread.sleep(250);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }*/
        }
    }

    /* Call this from the main activity to send data to the remote device */
    public void write(byte[] bytes) {
        try {
            outStream.write(bytes);
        } catch (IOException e) { }
    }

    /* Call this from the main activity to shutdown the connection */
    public void cancel() {
        try {
            connectedSocket.close();
        } catch (IOException e) { }
    }
}

}

然后我尝试在Handler中更新UI。

这是我申请样本的链接：

https://www.youtube.com/watch?v=_Buv64vADNk&feature=youtu.be

它不能顺利运行，有时候它没有响应。

你可以告诉我我做错了什么吗？ Thx提前。

Answer 1

Mateusz;查看操作块会强制您的代码进入后台，其优先级低于UI代码。您也可以尝试GCD。这是一个非常简单的代码块，作为一个单独的进程分离出来。

How to determine when all images have been downloaded from a set in Swift?

将UI代码置于最高优先级，将蓝牙置于最低优先级;确保您在UI更新中所做的唯一陈述是这样做的，不要在那里放置任何不更新UI的内容。

蓝牙更新UI线程

1 个答案: