Well unfortunately I don't have access to the logs
Connect your device with usb and use USB Debugging. It will list the log.
The Error is "Empty String" in a math calculation
In fact it is this code from you.
lblSum.Text = lblSum.Text + "0"
lblSum is empty at start. You are trying to do a math operation here.
add 0 to lblSum.Text.
To concat the value of lblSum.Text and the 0 (when pressing Button "1" seems wrong to me.
lblSum.Text = lblSum.Text & "0"
This was the case in all buttons.
Please find a slightly changes example.
i have changed
- all occurances of
lblSum.Text = lblSum.Text + "0"
with
lblSum.Text = lblSum.Text & "0"
to concat the String.
- all other numberbuttons other than the 0 to match the right number. You did used 0 in all...