我有一个运行功能 // Also maintains the per-device operation queue.
private class GattHandler extends BluetoothGattCallback
{
// Local copy of the key to BLE.mGatt. Fed by BLE.mNextGattHandle.
final int mHandle;
// The queue of operations.
LinkedList<Runnable> mOperations = new LinkedList<Runnable>();
// connect() and rssi() are handled separately from other operations.
CallbackContext mConnectContext;
CallbackContext mRssiContext;
CallbackContext mCurrentOpContext;
// Flag used when writing notification config descriptor.
// In this case we don't want to send back the result to JavaScript.
boolean mDontReportWriteDescriptor = false;
// The Android API connection.
BluetoothGatt mGatt;
// Maps of integer to Gatt subobject.
HashMap<Integer, BluetoothGattService> mServices;
HashMap<Integer, BluetoothGattCharacteristic> mCharacteristics;
HashMap<Integer, BluetoothGattDescriptor> mDescriptors;
// Monotonically incrementing key to the subobject maps.
int mNextHandle = 1;
// Notification callbacks. The BluetoothGattCharacteristic object, as found
// in the mCharacteristics map, is the key.
HashMap<BluetoothGattCharacteristic, CallbackContext> mNotifications =
new HashMap<BluetoothGattCharacteristic, CallbackContext>();
GattHandler(int h, CallbackContext cc)
{
mHandle = h;
mConnectContext = cc;
}
// Run the next operation, if any.
// TODO: Make another method processNext that sets mCurrentOpContext to
// null and calls process. That would clean up repeated code a bit.
// Also consider writing method that adds a runnable to the mOperations
// queue and calls process, this would also reduce some repeated code.
void process()
{
if (mCurrentOpContext != null) return;
Runnable runnable = mOperations.poll();
if (runnable == null) return;
runAction(runnable);
}
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState)
{
Log.i("@@@@@@", "@@@ onConnectionStateChange status: " + status + " newState: " + newState);
if (status == BluetoothGatt.GATT_SUCCESS)
{
try
{
JSONObject result = new JSONObject();
result.put("deviceHandle", mHandle);
result.put("state", newState);
Log.i("@@@@@@", "@@@ connect success");
keepCallback(mConnectContext, result);
}
catch(JSONException e)
{
Log.i("@@@@@@", "@@@ connect error: " + e);
e.printStackTrace();
mConnectContext.error("Connect error: " + e);
//assert(false);
}
}
else
{
// Could this be where we get 133? Yes it is.
Log.i("@@@@@@", "@@@ connect error - status: " + status);
mConnectContext.error(status);
}
}
的按钮。
askopenfilename这是函数filebutton = tk.Button(text = "Choose file ...",
command = lambda: openfile())
：
openfile一切正常，文件名被打印到控制台。但是我真正想要的是将文件名存储到一个变量中，这样我就可以像这样用熊猫从excel表格中读取数据：
def openfile():
filename = tkinter.filedialog.askopenfilename(filetypes = (("Excel", "*.xlsx"),
("All files", "*.*")))
print(filename)
我该如何实现？还是其他功能还有更好的方法？
答案 0 :(得分：1)
您无法在按钮函数调用中检索数据。如果您有全局变量，
def openfile():
global filename = tkinter.filedialog.askopenfilename(filetypes = (("Excel", "*.xlsx"),
("All files", "*.*")))
print(filename)
，您可以从按钮调用的函数外部访问它。
过去我是通过使用类来解决这个问题的。此tutorial在线将tkinter程序分为几类。如果遵循此结构，则可以创建类变量filename。这样，您就可以在该类的实例中操作文件。