This Activity already has an action bar supplied by the window decor.

[kierepka]

Error: java.lang.IllegalStateException: This Activity already has an action bar supplied by the window decor. Do not request Window.FEATURE_ACTION_BAR and set windowActionBar to false in your theme to use a Toolbar instead.

Code:

[Activity(Icon = "@drawable/icon", 
        ConfigurationChanges = AppConfig,
        Theme = CompatTheme)]
    public class MainActivity : AppCompatFormsApplicationActivity
    {
        const ConfigChanges AppConfig = ConfigChanges.Orientation | ConfigChanges.ScreenSize;

[kierepka]

ps. Theme = "@style/Theme.AppCompat.NoActionBar") instead Theme = CompatTheme is working but without actionbar :(

[amccorma]

It seems to be this line causing it in:
AppCompatFormsApplicationActivity.cs

        if (this.Toolbar == null)
        {
            this.Toolbar = new Toolbar(this);
            this.AppCompatDelegate.SetSupportActionBar(this.Toolbar);
        }

If you comment this out, it works. not sure what happens removing this line, but the themes work.

this line:
this.AppCompatDelegate.SetSupportActionBar(this.Toolbar);

causes the error. Anyone know why?

[amccorma]

Is there a way to apply a theme besides NoActionBar keeping the Toolbar?

[kierepka]

Hmm here on http://stackoverflow.com/questions/26515058/this-activity-already-has-an-action-bar-supplied-by-the-window-decor they are saying that we should use .NoActionBar theme. I try this solution, but without any luck (this same error). But It is working properly without this code ;)

[mikepham]

I will take a look when I get a chance. I haven't had the time to try the 1.5 packages yet.