translucent IOS7 導航欄 navigation bar 是否是半透明設置,子視圖是否從屏幕 0。0 開始
在IOS 7 有了新的解釋。
/* New behavior on iOS 7. Default is YES. You may force an opaque background by setting the property to NO. If the navigation bar has a custom
background image, the default is inferred from the alpha values of the image—YES if it has any pixel with alpha < 1.0 If you send setTranslucent:YES to a bar with an opaque custom background image it will apply a system opacity less than 1.0 to the image. If
you send setTranslucent:NO to a bar with a translucent custom background image it will provide an opaque background for the image using the bar's barTintColor if defined, or black for UIBarStyleBlack or white for UIBarStyleDefault if barTintColor is nil. */
@property(nonatomic,assign,getter=isTranslucent)BOOL translucentNS_AVAILABLE_IOS(3_0);
// Default is NO on iOS 6 and earlier. Always YES if barStyle is set to UIBarStyleBlackTranslucent
下面是抄過來的圖，可能更能說明問題，更直觀
