Android Question App stopping on click

[Erfan Kakaei]

Hello,
I was wondering if anyone could help me with this.
My app compiles just fine, but when I click on any button within it, it just stops and exits.
P.S: The only code within the mentioned buttons is to change the text inside a label.
As in:

label.Text = "1"

 

[DonManfred]

it just stops and exits

Check the log and post the full error. Without it is hard to give any advice.

If you have a small testproject. Upload it. In the IDE use File->Export as zip and upload this zip.

 

[mangojack]

I will take a wild shot ... Should the above code be Label1.Text = "1"

If this does not solve you problem ... follow @DonManfred instructions so we can help you further .

 

[Erfan Kakaei]

Check the log and post the full error. Without it is hard to give any advice.

If you have a small testproject. Upload it. In the IDE use File->Export as zip and upload this zip.

Well unfortunately I don't have access to the logs, but yes my project is small.
Here it is:

 

[Erfan Kakaei]

I will take a wild shot ... Should the above code be Label1.Text = "1"

If this does not solve you problem ... follow @DonManfred instructions so we can help you further .

Thank you sir, I just did.

 

[DonManfred]

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...

 

[Erfan Kakaei]

Thank you very much sir, it's been solved.
Now could you please tell me how I can set a number variable to Null?
For example let's say there's an integer with the value 4 inside it, and i'd like to have it empty as if it was just created.
And is the method the same as setting a string to Null?

 

[Erel]

A number variable can never be Null. It is also a mistake to set a string variable to null.