你可以手动检查屏幕大小来确定你在哪个设备上:

#define DEVICE_IS_IPHONE5 ([[UIScreen mainScreen] bounds].size.height == 568)

float height = DEVICE_IS_IPHONE5?568:480;
if (height == 568) {
    // 4"

} else {

    // 3"

}

你可以手动检查屏幕大小来确定你在哪个设备上:

#define DEVICE_IS_IPHONE5 ([[UIScreen mainScreen] bounds].size.height == 568)

float height = DEVICE_IS_IPHONE5?568:480;
if (height == 568) {
    // 4"

} else {

    // 3"

}

Download and install latest version of Xcode. Set a Launch Screen File for your app (in the general tab of your target settings). This is how you get to use the full size of any screen, including iPad split view sizes in iOS 9. Test your app, and hopefully do nothing else, since everything should work magically if you had set auto resizing masks properly, or used Auto Layout. If you didn't, adjust your view layouts, preferably with Auto Layout. If there is something you have to do for the larger screens specifically, then it looks like you have to check height of [[UIScreen mainScreen] bounds] as there seems to be no specific API for that. As of iOS 8 there are also size classes that abstract screen sizes into regular or compact vertically and horizontally and are recommended way to adapt your UI.

我建议在你的应用程序中根据你的UI界面使用自动调整蒙版，这节省了很多麻烦，比为iPhone 4和5屏幕制作不同的UI更好。

首先显示这张图片。在那个图像中，你显示了视网膜4支持的警告，所以点击这个警告，然后点击添加，这样你的视网膜4启动屏幕自动添加到你的项目中。

在你使用这段代码之后

if([[UIScreen mainScreen] bounds].size.height == 568)
    {
        // For iphone 5
    }
    else
    {
        // For iphone 4 or less
    }

唯一真正需要做的事情是在应用程序资源中添加一个名为“Default-568h@2x.png”的启动图像，在一般情况下(如果你足够幸运)应用程序将正常工作。

如果应用程序不处理触摸事件，那么确保键窗口有适当的大小。解决方法是设置适当的框架:

[window setFrame:[[UIScreen mainScreen] bounds]]

在迁移到iOS 6时，还有其他与屏幕大小无关的问题。详情请阅读iOS 6.0发布说明。