如何在 android 个线程中显示单个值

Question

在 android 中，我在移动设备上创建了一个基于 RFID 卡 Reader 的应用程序。当我在 RFID Reader 上点击卡片时，它会多次生成相同的值，直到卡片从 reader 中取消点击。

我想在 RFID reader 上每张刷卡只显示一个值。我在这里放置我的代码和我的应用程序的示例快照。

指导我并告诉我解决问题的方法。

public static MediaPlayer mp;
FT_Device ftDev = null;
int DevCount = -1;
int currentIndex = -1;
int openIndex = 0;

/*graphical objects*/
EditText readText;
Button readEnButton;
static int iEnableReadFlag = 1;

/*local variables*/
int baudRate; /*baud rate*/
byte stopBit; /*1:1stop bits, 2:2 stop bits*/
byte dataBit; /*8:8bit, 7: 7bit*/
byte parity;  /* 0: none, 1: odd, 2: even, 3: mark, 4: space*/
byte flowControl; /*0:none, 1: flow control(CTS,RTS)*/
int portNumber; /*port number*/
long wait_sec=3000;
byte[] readData;    //similar to data.
public static final int readLength = 1024;  // changed length from 512
public int iavailable = 0;

char[] readDataToText;
//char readDataToTextSudha;
public boolean bReadThreadGoing = false;
public readThread read_thread;
public static D2xxManager ftD2xx = null;
boolean uart_configured = false;

// Empty Constructor
public MainActivity() {
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    readData = new byte[readLength];
    readDataToText = new char[readLength];
    //readDataToTextSudha = new char;
    readText = (EditText) findViewById(R.id.ReadValues);
    readText.setInputType(0);
    readEnButton = (Button) findViewById(R.id.readEnButton);
    baudRate = 9600;
    /* default is stop bit 1 */
    stopBit = 1;
    /* default data bit is 8 bit */
    dataBit = 8;
    /* default is none */
    parity = 0;
    /* default flow control is is none */
    flowControl = 0;
    portNumber = 1;

    try {
        ftD2xx = D2xxManager.getInstance(this);
    } catch (D2xxManager.D2xxException ex) {
        ex.printStackTrace();
    }
    //Opening Coding

    if (DevCount <= 0) {
        createDeviceList();
    } else {
        connectFunction();
    }

    //Configuration coding

    if (DevCount <= 0 || ftDev == null) {
        Toast.makeText(getApplicationContext(), "Device not open yet...", Toast.LENGTH_SHORT).show();
    } else {
        SetConfig(baudRate, dataBit, stopBit, parity, flowControl);
    }

    readEnButton.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            if (DevCount <= 0 || ftDev == null) {
                Toast.makeText(getApplicationContext(), "Device not open yet...", Toast.LENGTH_SHORT).show();
            } else if (uart_configured == false) {
                Toast.makeText(getApplicationContext(), "UART not configure yet...", Toast.LENGTH_SHORT).show();
                return;
            } else {
                EnableRead();
            }
        }
    });

}

public void EnableRead() {
    iEnableReadFlag = (iEnableReadFlag + 1) % 2;
    if (iEnableReadFlag == 1) {
        ftDev.purge((byte) (D2xxManager.FT_PURGE_TX));
        ftDev.restartInTask();
        readEnButton.setText("Read Enabled");
        Toast.makeText(getApplicationContext(),"Read Enabled",Toast.LENGTH_LONG).show();

    } else {
        ftDev.stopInTask();
        readEnButton.setText("Read Disabled");
        Toast.makeText(getApplicationContext(),"Read Disabled",Toast.LENGTH_LONG).show();
    }
}

public void createDeviceList() {
    int tempDevCount = ftD2xx.createDeviceInfoList(getApplicationContext());

    if (tempDevCount > 0) {
        if (DevCount != tempDevCount) {
            DevCount = tempDevCount;
            updatePortNumberSelector();
        }
    } else {
        DevCount = -1;
        currentIndex = -1;
    }
};

public void disconnectFunction() {
    DevCount = -1;
    currentIndex = -1;
    bReadThreadGoing = false;
    try {
        Thread.sleep(1000);
    } catch (InterruptedException e) {
        e.printStackTrace();
    }

    if (ftDev != null) {
        synchronized (ftDev) {
            if (true == ftDev.isOpen()) {
                ftDev.close();
            }
        }
    }
}

public void connectFunction() {
    int tmpProtNumber = openIndex + 1;

    if (currentIndex != openIndex) {
        if (null == ftDev) {
            ftDev = ftD2xx.openByIndex(getApplicationContext(), openIndex);
        } else {
            synchronized (ftDev) {
                ftDev = ftD2xx.openByIndex(getApplicationContext(), openIndex);
            }
        }
        uart_configured = false;
    } else {
        Toast.makeText(getApplicationContext(), "Device port " + tmpProtNumber + " is already opened", Toast.LENGTH_LONG).show();
        return;
    }

    if (ftDev == null) {
        Toast.makeText(getApplicationContext(), "open device port(" + tmpProtNumber + ") NG, ftDev == null", Toast.LENGTH_LONG).show();
        return;
    }

    if (true == ftDev.isOpen()) {
        currentIndex = openIndex;
        Toast.makeText(getApplicationContext(), "open device port(" + tmpProtNumber + ") OK", Toast.LENGTH_SHORT).show();

        if (false == bReadThreadGoing) {
            read_thread = new readThread(handler);
            read_thread.start();
            bReadThreadGoing = true;
        }
    } else {
        Toast.makeText(getApplicationContext(), "open device port(" + tmpProtNumber + ") NG", Toast.LENGTH_LONG).show();
    }
}

public void updatePortNumberSelector() {
    if (DevCount == 2) {
        Toast.makeText(getApplicationContext(), "2 port device attached", Toast.LENGTH_SHORT).show();

    } else if (DevCount == 4) {

        Toast.makeText(getApplicationContext(), "4 port device attached", Toast.LENGTH_SHORT).show();

    } else {
        Toast.makeText(getApplicationContext(), "1 port device attached", Toast.LENGTH_SHORT).show();
    }
}

public void SetConfig(int baud, byte dataBits, byte stopBits, byte parity, byte flowControl) {
    if (ftDev.isOpen() == false) {
        Log.e("j2xx", "SetConfig: device not open");
        return;
    }

    ftDev.setBitMode((byte) 0, D2xxManager.FT_BITMODE_RESET);
    ftDev.setBaudRate(baud);


    ftDev.setDataCharacteristics(dataBits, stopBits, parity);

    uart_configured = true;
    Toast.makeText(getApplicationContext(), "Config done", Toast.LENGTH_SHORT).show();
}


final Handler handler = new Handler() {
    @Override
    public void handleMessage(Message msg) {
        if (iavailable > 0) {

            mp = MediaPlayer.create(MainActivity.this, R.raw.beep);
            mp.start();
            readText.append(String.copyValueOf(readDataToText, 0, iavailable));
        }
    }
};

private class readThread extends Thread {
    Handler mHandler;

    readThread(Handler h) {
        mHandler = h;
        this.setPriority(Thread.MIN_PRIORITY);
    }

    @Override
    public void run() {
        int i;

        while (true == bReadThreadGoing) {
            try {
                Thread.sleep(1000); //changed
            }   catch (InterruptedException e) {
            }

            synchronized (ftDev) {
                iavailable = ftDev.getQueueStatus();
                if (iavailable > 0) {

                    if (iavailable > readLength) {
                        iavailable = readLength;
                    }
                    ftDev.read(readData, iavailable,wait_sec);
                    for (i = 0; i < iavailable; i++) {
                       readDataToText[i] = (char) readData[i];

                    }
                    Message msg = mHandler.obtainMessage();
                    mHandler.sendMessage(msg);
                }
            }
        }
    }

}

@Override
public void onResume() {
    super.onResume();
    DevCount = 0;
    createDeviceList();
    if (DevCount > 0) {
        connectFunction();
        SetConfig(baudRate, dataBit, stopBit, parity, flowControl);
    }
}
}

我的问题会在这里解决

Getting Value continuously from Reader

I want this type of value when i tap the card

如果我点击一些其他的牌，旧牌的价值会被新的取代。

指导我。提前致谢

Answer 1

我通过使用线程得到了答案。当卡点击它在 sleep 一两秒后获得一些值时，只有下一个值必须从 reader.

获得

 public void run() {
        int i;
        while (true == bReadThreadGoing) {  // Means Make sure , getting value from Reader
            try {
                Thread.sleep(1000);         // Wait for a second to get another value.
                clearText();                //clear the old value and get new value. 
            }   catch (InterruptedException e) {
            }

并使用此命令清除编辑文本。

      public void clearText() {
    runOnUiThread(new Runnable() {
        public void run() {
          readText.setText("");
        }
    });
}

如何在 android 个线程中显示单个值

How to display a single value in android Threads

multithreading

android

rfid

handler

cardreader