OSX：如何保持与旧版OSX / SDK的兼容性

Question

I have a piece of code like this:

        AVCaptureScreenInput *input = [[AVCaptureScreenInput alloc] initWithDisplayID:screen.displayID];
        input.capturesCursor = NO;
        input.capturesMouseClicks = NO;

AVCaptureScreenInput.capturesCursor is only available in 10.8+. My app supports 10.7+.

How do I maintain compatibility? Should I remove the call completely? Check the OS version at runtime?

Answer 1

You should check if the property exists in runtime.

This code should do the trick:

AVCaptureScreenInput *input = [[AVCaptureScreenInput alloc] initWithDisplayID:screen.displayID];
if ([input respondsToSelector:@selector(setCapturesCursor:)]) {
    input.capturesCursor = NO;
}
input.capturesMouseClicks = NO;