Applications using Launch Screen Files and targetting iOS 7.1 and earlier

在使用xcode6建的項目時，有時在ios7模擬器下會出現一下情況

導航欄上方和tabbar下方會有黑邊

並且會有一下警告：

Applications using Launch Screen Files and targetting iOS 7.1 and earlier need to also include a Launch Image in an Asset Catalog.

解決方案：

1、選擇launch images  use asset catalog

2、點擊migrate

3、完美解決問題，沒有警告。