iphone-3gs

问题 I am trying to pick a video from the photo library. In principle I know how to do it you set the mediaType of the image picker to an NSArray with kUTTypeMovie as its only object. But this doesn't seem to work on an iPhone 3G. Since OS 3.1 you can store videos you've received in your photo library. When you start the build in 'Photos' application the videos appear. However this doesn't work using the UIImagePickerController. The controller reports that it only supports images. When you try to

问题 When i am connecting my 3gs(iOS 5.0.1) device to Instruments i am getting this error message " Failed to start Instruments daemon for 'iOS' on iPhone 3GS (v5.0.1)' (The service is invalid.) Please reconnect the device." This message appears on instruments, when ever i re-connect the device. How can i do performance testing with this device. Thanks. 回答1: I have no idea what is causing this - but i did find a solution that worked on both devices that caused instruments pop out this message -

问题 Is it possible to have an embedded MKMapView rotate to always face the direction the iPhone is facing? Basically I want to mimic the Map app rotation feature on my own app. I see that the iPhone SDK does not expose the functionality. However, I wonder if it would work to rotate the entire view using CGAffineTransformMakeRotate . Would it affect tapping and zooming? Is there a better way? 回答1: To rotate the mapView but not the annotations you could use the following code to compensate for the