How to dismiss an AlertDialog on a FlatButton clic

问题:

I have the following AlertDialog.

showDialog(
            context: context,
            child: new AlertDialog(
              title: const Text("Location disabled"),
              content: const Text(
                  """
Location is disabled on this device. Please enable it and try again.
                  """),
              actions: [
                new FlatButton(
                  child: const Text("Ok"),
                  onPressed: _dismissDialog,
                ),
              ],
            ),
        );

How can I make _dismissDialog() dismiss said AlertDialog?

回答1:

Navigator.pop() should do the trick. You can also use that to return the result of the dialog (if it presented the user with choices)

回答2:

Navigator.of(context, rootNavigator: true).pop('dialog')

worked with me.

回答3:

If you don't want to return any result, use either of them:

Navigator.of(context).pop();
Navigator.pop(context);

---

But if you do want to return some result, see this

Example:

showDialog(
    context: context,
    builder: (_) {
      return AlertDialog(
        title: Text('Wanna Exit?'),
        actions: [
          FlatButton(
            onPressed: () => Navigator.pop(context, false), // passing false
            child: Text('No'),
          ),
          FlatButton(
            onPressed: () => Navigator.pop(context, true), // passing true
            child: Text('Yes'),
          ),
        ],
      );
    }).then((exit) {
  if (exit == null) return;

  if (exit) {
    // user pressed Yes button
  } else {
    // user pressed No button
  }
});

回答4:

Navigator.pop(_)

worked for me, but the Flutter Team's gallery contains an example using:

Navigator.of(context, rootNavigator: true).pop()

which also works, and I am tempted to follow their lead.

回答5:

This works Prefectly

      RaisedButton(
                child: Text(
                  "Cancel",
                  style: TextStyle(color: Colors.white),
                ),
                color: Colors.blue,
                onPressed: () => Navigator.pop(context),
              ),

回答6:

Example of dismissing alert dialog on flat button click

RaisedButton(
        onPressed: () {
          showDialog(
              context: context,
              builder: (context) => AlertDialog(
                    title: Text('Are you sure?'),
                    content: Text('Do you want to remove item?'),
                    actions: <Widget>[
                      FlatButton(
                          onPressed: () => Navigator.of(context).pop(false),//  We can return any object from here
                           child: Text('NO')),
                      FlatButton(
                          onPressed: () => Navigator.of(context).pop(true), //  We can return any object from here
                          child: Text('YES'))
                    ],
                  )).then((value) =>
              print('Selected Alert Option: ' + value.toString()));
        },
        child: Text('Show Alert Dialog'),
      ),

Above code have two unique things which is used to provide callback result of dialog

Navigator.of(context).pop(false) -- return false value when we pressed NO Navigator.of(context).pop(true) -- return true value when we pressed YES

Based on these return value, we can perform some operation outside of it or maintain the dialog status value

回答7:

Use Navigator.pop(context);

Example

showDialog(
            context: context,
            child: new AlertDialog(
              title: const Text("Location disabled"),
              content: const Text(
                  """
Location is disabled on this device. Please enable it and try again.
                  """),
              actions: [
                new FlatButton(
                  child: const Text("Ok"),
                  onPressed: () {
                      Navigator.pop(context);
                    },
                ),
              ],
            ),
        );

回答8:

The accepted answer states how to dismiss a dialog using the Navigator Class. To dismiss a dialog without using Navigator you can set the onPressed event of the button to the following:

setState((){
  thisAlertDialog = null; 
});

In case the code above is not self-explanatory it is basically setting the Parent AlertDialog of the FlatButton to null, thus dismissing it.