I Have a form Key But Flutter Still Gives Me An Error When Running Validate

[Mr harilall]

Hi,

I have created a form key

final _formKey = GlobalKey<FormState>();

I have also assigned this key to my form

Form( key: _formKey)

Then in my Raised Button's onPressed method I have this code to disable the button if the form is invalid

onPressed: (_formKey.currentState.validate() || _photoCount == 0) ? null : () {},

Now as far as I know this code is only supposed to run once the button is actually pressed but it seems to fire once the view is loaded somehow and it gives me the following error

NoSuchMethodError: The method 'validate' was called on null. Receiver: null Tried calling: validate()

I have also been through every text and number input and made sure they all have validator functions but that didn't work. How do I resolve this?

[Olaide Nojeem Ekeolere]

Hi,

    Because the onPressed is being fired immediately the widget builds modify as: onPressed: ()=> (_formKey.currentState.validate() || _photoCount == 0) ? null : () {},

Best regards

Olaide Nojeem Ekeolere

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[Mr harilall]

Ok so how do I rectify this?

On Thursday, February 20, 2020 at 11:13:47 AM UTC+2, Olaide Nojeem Ekeolere wrote:

Hi,

    Because the onPressed is being fired immediately the widget builds modify as: onPressed: ()=> (_formKey.currentState.validate() || _photoCount == 0) ? null : () {},

Best regards

Olaide Nojeem Ekeolere

On Thu, 20 Feb 2020 at 10:10, Mr harilall <harila...@gmail.com> wrote:

Hi,

I have created a form key

final _formKey = GlobalKey<FormState>();

I have also assigned this key to my form

Form( key: _formKey)

Then in my Raised Button's onPressed method I have this code to disable the button if the form is invalid

onPressed: (_formKey.currentState.validate() || _photoCount == 0) ? null : () {},

Now as far as I know this code is only supposed to run once the button is actually pressed but it seems to fire once the view is loaded somehow and it gives me the following error

NoSuchMethodError: The method 'validate' was called on null. Receiver: null Tried calling: validate()

I have also been through every text and number input and made sure they all have validator functions but that didn't work. How do I resolve this?

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[Olaide Nojeem Ekeolere]

Hi,

Try   onPressed: ((_formKey.currentState!=null&&!_formKey.currentState.validate()) || _photoCount == 0) ? null : () {},

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