         layout.itemSize=PbSystem.screenCurrentSize(true)
         self.collectionView?.setCollectionViewLayout(layout,animated: false)
         
-        //pageControl
-        let metrics=["width":self.pageControlSize().width,"height":self.pageControlSize().height]
-        let views=["pageControl":self.pageControl]
-        self.view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:[pageControl(==height)]-20-|", options: NSLayoutFormatOptions.AlignAllBaseline, metrics: metrics, views:views))
-        self.view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:[pageControl(==width)]", options: NSLayoutFormatOptions.AlignAllBaseline, metrics: metrics, views:views))
+        //pageControl+startButton
+        let metrics=["width":self.pageControlSize().width,"height":self.pageControlSize().height,"btnWidth":self.startButtonSize().width,"btnHeight":self.startButtonSize().height,"margin":20]
+        let views=["pageControl":self.pageControl,"startButton":self.startButton]
+        //纵向
+        self.view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:[startButton(==btnHeight)]-margin-[pageControl(==height)]-margin-|", options:.AlignAllCenterX, metrics: metrics, views:views))
+        //横向
+        self.view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:[pageControl(==width)]", options:.AlignAllBaseline, metrics: metrics, views:views))
+        self.view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:[startButton(==btnWidth)]", options:.AlignAllBaseline, metrics: metrics, views:views))
+        //中心位置
         self.view.addConstraint(NSLayoutConstraint(item: self.view, attribute:.CenterX, relatedBy:.Equal, toItem: self.pageControl,attribute:.CenterX, multiplier: 1, constant: 0))
+        self.view.addConstraint(NSLayoutConstraint(item: self.view, attribute:.CenterX, relatedBy:.Equal, toItem: self.startButton,attribute:.CenterX, multiplier: 1, constant: 0))
+    }
+    
+    //displayStartButton:显示进入按钮
+    private func displayStartButton(show:Bool)
+    {
+        if(show)
+        {
+            UIView.animateWithDuration(0.1, animations: { () -> Void in
+                self.startButton.layer.opacity=1
+                }) { (finished) -> Void in
+                    
+            }
+        }
+        else
+        {
+            UIView.animateWithDuration(0.1, animations: { () -> Void in
+                self.startButton.layer.opacity=0
+                }) { (finished) -> Void in
+                    
+            }
+        }
     }
     
     //scrollViewDidScroll:滚动时执行粘土动画

    override func scrollViewDidEndDecelerating(scrollView: UIScrollView)
    {
        self.pageControl.indicator.lastContentOffset=scrollView.contentOffset.x
    }
    
    //scrollViewDidEndScrollingAnimation:结束滚动动画，记录最后位置
    override func scrollViewDidEndScrollingAnimation(scrollView: UIScrollView)
    {
        self.pageControl.indicator.lastContentOffset=scrollView.contentOffset.x
    }
}

        self.pageControl.swipeEnable = true
        self.pageControl.frame=CGRectMake(0, 0,self.pageControlSize().width,self.pageControlSize().height)
        
        //startButton
        self.startButton.setTranslatesAutoresizingMaskIntoConstraints(false)
        self.startButton.setTitle("开始使用",forState:.Normal)
        self.startButton.setTitleColor(UIColor.darkGrayColor(),forState:.Normal)
        self.startButton.setBackgroundImage(UIImage.imageWithColor(UIColor.smokeWhiteColor(), size: self.startButtonSize()), forState: UIControlState.Normal)
        self.startButton.clipsToBounds=true
        self.startButton.layer.opacity=0
        
        //collectionView
        self.collectionView?.backgroundColor=UIColor.whiteColor()
        self.collectionView?.showsHorizontalScrollIndicator=false
