无论设备如何,我应该怎么做才能确保工具栏位于底部?

What should I be doing to ensure the toolbar sits at the bottom, irrespective of the device?

我创建了一个视图 (MyOverlayView.xib) 并在视图底部添加了一个工具栏并将约束设置为 (left: 0, bottom, 0: right: 0) 我现在添加这个到我的视图控制器中的 UIImagePickerController,如下所示:

let cameraController = UIImagePickerController()
if (cameraController != nil) {
    cameraController!.mediaTypes = [kUTTypeMovie as String]
    cameraController!.sourceType = .Camera
    cameraController!.cameraCaptureMode = .Video

    cameraController!.allowsEditing = false
    cameraController!.delegate = self
    cameraController!.showsCameraControls = false


    self.myOverlayView = (NSBundle.mainBundle().loadNibNamed("MyOverlayView", owner: self, options: nil)[0] as! MyOverlayView)

    if (self.myOverlayView != nil) {            
        self.myOverlayView!.frame = self.view!.frame            
        myOverlayView?.delegate = self;         
    } else {
        print("view not loaded")
    }
}

问题是,虽然它看起来位于界面生成器的底部,但在我的 phone 上却位于屏幕的一半之外。无论使用何种设备,我应该怎么做才能确保工具栏位于底部?

XCode7.2.1,Swift2,iOS9.x

我通过在视图中选择 UIToolber 项,然后在 "resolve auto layout issues" 项中单击 "reset to suggested constraints" 来解决此问题。