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没什么好说的代码如下
头文件
/*
Erica Sadun, http://ericasadun.com iPhone Developer's Cookbook, 3.0 Edition BSD License, Use at your own risk */ #import <UIKit/UIKit.h> @interface UIDevice (Orientation) <UIAccelerometerDelegate> - (BOOL) isLandscape; - (BOOL) isPortrait; - (NSString *) orientationString; - (float) orientationAngleRelativeToOrientation:(UIDeviceOrientation) someOrientation; @property (nonatomic, readonly) BOOL isLandscape; @property (nonatomic, readonly) BOOL isPortrait; @property (nonatomic, readonly) NSString *orientationString; @property (nonatomic, readonly) float orientationAngle; @end
实现文件///
/*
Erica Sadun, http://ericasadun.com iPhone Developer's Cookbook, 3.0 Edition BSD License, Use at your own risk */ // Thanks jweinberg, Emanuele Vulcano, rincewind42, Jonah Williams #import "UIDevice-Orientation.h" @implementation UIDevice (Orientation) float device_angle; CFRunLoopRef currentLoop; - (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration { float xx = [acceleration x]; float yy = -[acceleration y]; device_angle = M_PI / 2.0f - atan2(yy, xx); CFRunLoopStop(currentLoop); } - (float) orientationAngle { #if TARGET_IPHONE_SIMULATOR // NSLog( @"Running in the simulator!" ); switch (self.orientation) { case UIDeviceOrientationPortrait: return 0.0f; case UIDeviceOrientationPortraitUpsideDown: return M_PI; case UIDeviceOrientationLandscapeLeft: return -(M_PI/2.0f); case UIDeviceOrientationLandscapeRight: return (M_PI/2.0f); default: return 0.0f; } #else id accelerometer_delegate = [UIAccelerometer sharedAccelerometer].delegate; [UIAccelerometer sharedAccelerometer].delegate = self; // Wait for a reading currentLoop = CFRunLoopGetCurrent(); CFRunLoopRun(); [UIAccelerometer sharedAccelerometer].delegate = accelerometer_delegate; return device_angle; #endif } // Thanks Jonah Williams - (float) orientationAngleRelativeToOrientation:(UIDeviceOrientation) someOrientation { float dOrientation = 0.0f; switch (someOrientation) { case UIDeviceOrientationPortraitUpsideDown: {dOrientation = M_PI; break;} case UIDeviceOrientationLandscapeLeft: {dOrientation = -(M_PI/2.0f); break;} case UIDeviceOrientationLandscapeRight: {dOrientation = (M_PI/2.0f); break;} default: break; } float adjustedAngle = fmod(self.orientationAngle - dOrientation, 2.0f * M_PI); if (adjustedAngle > (M_PI + 0.01f)) adjustedAngle = (adjustedAngle - 2.0f * M_PI); return adjustedAngle; } - (BOOL) isLandscape { return UIDeviceOrientationIsLandscape(self.orientation); } - (BOOL) isPortrait { return UIDeviceOrientationIsPortrait(self.orientation); } - (NSString *) orientationString { switch ([[UIDevice currentDevice] orientation]) { case UIDeviceOrientationUnknown: return @"Unknown"; case UIDeviceOrientationPortrait: return @"Portrait"; case UIDeviceOrientationPortraitUpsideDown: return @"Portrait Upside Down"; case UIDeviceOrientationLandscapeLeft: return @"Landscape Left"; case UIDeviceOrientationLandscapeRight: return @"Landscape Right"; case UIDeviceOrientationFaceUp: return @"Face Up"; case UIDeviceOrientationFaceDown: return @"Face Down"; default: break; } return nil; } @end