I would like to Gone the button

Question

In xamarin Android we have "Visibility.Gone;" to hide the button. In Xamarin Forms we have IsVisible="{Binding State}", but this only will make view invisible, space remain there.

Please let me know solution. Regards

Answer 1

In your view model you need to have something similar to the following:

public bool State{
    get {
        return _state;
    }
    set {
        _state= value;
        RaisePropertyChanged ("State");
    }
}

According to the Xamarin documentation found here the element should be removed from the visual tree and not take up any space.

Edit:
I'm not sure how you're setting the Column="5" on your grid. There is no attribute for Grid that contains column; however, I am able to produce the effect you looking for with the following code.

 <Grid BackgroundColor="Gray">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="Auto" />
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="50" />
        </Grid.RowDefinitions>
        <Grid.Padding>
            <OnPlatform x:TypeArguments="Thickness" iOS="0,-3,-20,-3" Android="0, -5, 0, -5" WinPhone="20, 20, 20, 20" />
        </Grid.Padding>
        <BoxView Color="Blue" Grid.Column="0"></BoxView>
        <BoxView Color="Green" Grid.Column="1" IsVisible="{Binding State}"></BoxView>
        <BoxView Color="Blue" Grid.Column="2"></BoxView>
        <BoxView Color="Green" Grid.Column="3"></BoxView>
    </Grid>

Details:
You are correct in that setting the label visibility to false in a grid will maintain the space allocated to the control in the grid. What you can do is set the grid <ColumnDefinition Width="Auto" /> or <RowDefinition Height="Auto" /> and put your label into that column or row. This will automatically remove the space allocated for the control when the visibility is set to false. Below is a screenshot of the effect you are getting (left) and the effect after setting the Definition to Auto (right).