iPhone toolbar拖拽效果 代码实例

#import <UIKit/UIKit.h> #import "math.h" @interface BrightnessController : UIViewController { int brightness; } @end @implementation BrightnessController // MyCreateBitmapContext: Source based on Apple Sample Code CGContextRef MyCreateBitmapContext (int pixelsWide, int pixelsHigh) { CGContextRef context = NULL; CGColorSpaceRef colorSpace; void * bitmapData; int bitmapByteCount; int bitmapBytesPerRow; bitmapBytesPerRow = (pixelsWide * 4); bitmapByteCount = (bitmapBytesPerRow * pixelsHigh); colorSpace = CGColorSpaceCreateDeviceRGB(); bitmapData = malloc( bitmapByteCount ); if (bitmapData == NULL) { fprintf (stderr, "Memory not allocated!"); CGColorSpaceRelease( colorSpace ); return NULL; } context = CGBitmapContextCreate (bitmapData, pixelsWide, pixelsHigh, 8, bitmapBytesPerRow, colorSpace, kCGImageAlphaPremultipliedLast); if (context== NULL) { free (bitmapData); fprintf (stderr, "Context not created!"); return NULL; } CGColorSpaceRelease( colorSpace ); return context; } // addRoundedRectToPath: Source based on Apple Sample Code static void addRoundedRectToPath(CGContextRef context, CGRect rect, float ovalWidth, float ovalHeight) { float fw, fh; if (ovalWidth == 0 || ovalHeight == 0) { CGContextAddRect(context, rect); return; } CGContextSaveGState(context); CGContextTranslateCTM(context, CGRectGetMinX(rect), CGRectGetMinY(rect)); CGContextScaleCTM(context, ovalWidth, ovalHeight); fw = CGRectGetWidth(rect) / ovalWidth; fh = CGRectGetHeight(rect) / ovalHeight; CGContextMoveToPoint(context, fw, fh/2); // Start at lower right corner CGContextAddArcToPoint(context, fw, fh, fw/2, fh, 1); // Top right corner CGContextAddArcToPoint(context, 0, fh, 0, fh/2, 1); // Top left corner CGContextAddArcToPoint(context, 0, 0, fw/2, 0, 1); // Lower left corner CGContextAddArcToPoint(context, fw, 0, fw, fh/2, 1); // Back to lower right CGContextClosePath(context); CGContextRestoreGState(context); } // Build an image tinted at the given percentage id createImage(float percentage) { CGContextRef context = MyCreateBitmapContext(30, 30); addRoundedRectToPath(context, CGRectMake(0.0f, 0.0f, 30.0f, 30.0f), 4.0f, 4.0f); CGFloat gray[4] = {percentage, percentage, percentage, 1.0f}; CGContextSetFillColor(context, gray); CGContextFillPath(context); CGImageRef myRef = CGBitmapContextCreateImage (context); free(CGBitmapContextGetData(context)); CGContextRelease(context); return [UIImage imageWithCGImage:myRef]; } #define MAXDEPTH 8 -(BrightnessController *) initWithBrightness: (int) aBrightness { self = [super init]; brightness = aBrightness; self.title = [NSString stringWithFormat:@"%d%%", brightness * 10]; [self.tabBarItem initWithTitle:self.title image:createImage(((float) brightness / 10.0f)) tag:0]; return self; } - (void)loadView { UIView *contentView = [[UIView alloc] init]; float percent = brightness * 0.1; contentView.backgroundColor = [UIColor colorWithRed:percent green:percent blue:percent alpha:1.0]; contentView.autoresizesSubviews = YES; contentView.autoresizingMask = (UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight); self.view = contentView; [contentView release]; } @end @interface SampleAppDelegate : NSObject <UIApplicationDelegate, UITabBarControllerDelegate> @end @implementation SampleAppDelegate - (void)applicationDidFinishLaunching:(UIApplication *)application { UIWindow *window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; // Create the array of UIViewControllers NSMutableArray *controllers = [[NSMutableArray alloc] init]; for (int i = 0; i < 11; i++) { BrightnessController *bControl = [[BrightnessController alloc] initWithBrightness:i]; UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:bControl]; nav.navigationBar.barStyle = UIBarStyleBlackTranslucent; [controllers addObject:nav]; [bControl release]; [nav release]; } // Create the toolbar and add the view controllers UITabBarController *tbarController = [[UITabBarController alloc] init]; tbarController.viewControllers = controllers; tbarController.customizableViewControllers = controllers; tbarController.delegate = self; // Set up the window [window addSubview:tbarController.view]; [window makeKeyAndVisible]; [controllers release]; } @end int main(int argc, char *argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; int retVal = UIApplicationMain(argc, argv, nil, @"SampleAppDelegate"); [pool release]; return retVal; }