如何使导航栏像iPhone中的照片应用程序一样透明和淡出

Question

i am new to iPhone Programming ...can anybody help me out please..

i want to develop an app like photo app in iPhone..

How to make the naveigation bar and toolbar transparent and fadeout like in photo app in iPhone

Thank u ..

Answer 1

UINavigationBar inherits from UIView , so you can use UIView 's animation methods to fade it out by setting the alpha property to 0. This should work:

[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.5];
[navigationBar setAlpha:0.0];
[UIView commitAnimations];

Answer 2

Since I'm a block-using kinda guy, I use this little snippet.

[UIView animateWithDuration:0.5 animations:^{
    [navigationBar setAlpha:0.0];
}];

Feels nicer to me, but you should probably only do this if you're used to blocks and you're rockin' iOS 4.0 or later.

Answer 3

To make the bar transparent, using setBarStyle: using the UIBarStyleBlackTranslucent .

To hide the bar with fade animation, use the code snippet Macatomy posted.

Answer 4

According to Apple specs, you should never change the frame , bounds , or alpha values of the navigation bar.

To hide (or show) the navigation bar, you can change the navigationBarHidden property or call the setNavigationBarHidden:animated method.