1、问题描述

最近进行Android ble的开发，遇到最大的问题就是在往characteristic中写入数据的时候，会有一个成功率抖动的问题，常会出现第一次写入失败，必须再写一次才成功的情况。

每次往characteristic中写入数据的时候，应该要回调onCharacteristicWrite这个方法的，如果失败了，根本就不回调这个方法，导致我甚至无出判断成功还是失败，无法再逻辑代码中去重写，只能在交互界面重复操作。

2、具体代码

下面我贴出我大致代码。

2.1BluetoothGattCallback

private void connectDevice() {

mDevice.connectGatt(this, false, new BluetoothGattCallback() {

@Override

public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {

if (newState == BluetoothProfile.STATE_CONNECTED) {

Log.d("MainActivity", "连接成功");

mGatt = gatt;

mGatt.connect();

gatt.discoverServices();

}

}

@Override

public void onServicesDiscovered(final BluetoothGatt gatt, int status) {

if (status == BluetoothGatt.GATT_SUCCESS) {

List<BluetoothGattService> services = gatt.getServices();

mGattService = services.get(4);

BluetoothGattCharacteristic notificationCharacteristic = mGattService.getCharacteristics().get(0);

mWriteCharacteristic = services.get(4).getCharacteristics().get(1);

mSimpleIO.setString("notificationUUID", notificationCharacteristic.getUuid().toString());

gatt.setCharacteristicNotification(notificationCharacteristic, true);

}

}

@Override

public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {

if (status == BluetoothGatt.GATT_SUCCESS) {

switch (mCurrState) {

case ConstantContainer.VERIFY_DEFAULT_KEY:

alterNewKey(gatt, characteristic);

break;

case ConstantContainer.ALTER_KEY:

bondSuccess();

break;

case ConstantContainer.REMOVE_BOND:

mGatt.disconnect();

try {

if (removeBond(mDevice)) {

mSimpleIO.remove("deviceAddress");

mSimpleIO.remove("notificationUUID");

runOnUiThread(new Runnable() {

@Override

public void run() {

showFindLayout();

}

});

}

} catch (Exception e) {

e.printStackTrace();

}

break;

}

} else {

switch (mCurrState) {

case ConstantContainer.VERIFY_DEFAULT_KEY:

Log.d("BluetoothActivity", "验证初始密码失败");

break;

case ConstantContainer.ALTER_KEY:

Log.d("BluetoothActivity", "修改密码失败");

break;

case ConstantContainer.REMOVE_BOND:

Log.d("BluetoothActivity", "删除配对失败");

break;

}

}

}

@Override

public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {

}

});

上面的代码是BluetoothGattCallback的几个主要回调，可以看到我在onCharacteristicWrite中对他的status做了判断，想要定位写入是否成功，但结果是失败的情况下，并不回调这个方法。

2.2 写入部分

private void alterNewKey(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {

mWriteCharacteristic.setValue("BBTM=" + mBlueKey);

mCurrState = ConstantContainer.ALTER_KEY;

Log.d("BluetoothActivity", "gatt.writeCharacteristic(characteristic) alterNewKey:" + gatt.writeCharacteristic(characteristic));

}

private void writeDefaultKey(BluetoothGatt gatt, BluetoothGattCharacteristic mWriteCharacteristic) {

mCurrState = ConstantContainer.VERIFY_DEFAULT_KEY;

mWriteCharacteristic.setValue(ConstantContainer.DEFAULT_KEY);

Log.d("BluetoothActivity", "gatt.writeCharacteristic(mWriteCharacteristic) writeDefaultKey:" + gatt.writeCharacteristic(mWriteCharacteristic));

}

这两个方法是我写入的部分，我把它们的返回值打印出来可发现，无论成功失败，返回的都是true。