iOS UIPopoverView的使用

UIViewController *contentViewController = [[UIViewController alloc] init];
contentViewController.view.backgroundColor = [UIColor yellowColor];

UIPopoverController *popController = [[UIPopoverController alloc] initWithContentViewController:contentViewController];
//    popController.popoverBackgroundViewClass = [PopoverBackgroundView class];
popController.popoverContentSize = CGSizeMake(300.0f, 100);
self.popController = popController;

UIButton * button = [UIButton buttonWithType:UIButtonTypeCustom];
button.frame = CGRectMake(20, 20, 100, 30);
button.backgroundColor = [UIColor redColor];
[button addTarget:self action:@selector(buttonAction) forControlEvents:UIControlEventTouchUpInside];
[contentViewController.view addSubview:button];

[self.popController presentPopoverFromBarButtonItem:sender
permittedArrowDirections:UIPopoverArrowDirectionUp
animated:YES];

#import <UIKit/UIKit.h>
@interface PopoverBackgroundView : UIPopoverBackgroundView
@end

#import "PopoverBackgroundView.h"
#define kArrowBase 30.0f
#define kArrowHeight 20.0f
#define kBorderInset 0.0f

@interface PopoverBackgroundView()
@property (nonatomic, strong) UIImageView *arrowImageView;
- (UIImage *)drawArrowImage:(CGSize)size;
@end

@implementation PopoverBackgroundView

@synthesize arrowDirection  = _arrowDirection;
@synthesize arrowOffset     = _arrowOffset;

#pragma mark - Graphics Methods
- (UIImage *)drawArrowImage:(CGSize)size
{
UIGraphicsBeginImageContextWithOptions(size, NO, 0);
CGContextRef ctx = UIGraphicsGetCurrentContext();
[[UIColor clearColor] setFill];
CGContextFillRect(ctx, CGRectMake(0.0f, 0.0f, size.width, size.height));

CGMutablePathRef arrowPath = CGPathCreateMutable();
CGPathMoveToPoint(arrowPath, NULL, (size.width/2.0f), 0.0f); //Top Center
CGPathAddLineToPoint(arrowPath, NULL, size.width, size.height); //Bottom Right
CGPathAddLineToPoint(arrowPath, NULL, 0.0f, size.height); //Bottom Right
CGPathCloseSubpath(arrowPath);
CGContextAddPath(ctx, arrowPath);
CGPathRelease(arrowPath);

UIColor *fillColor = [UIColor yellowColor];
CGContextSetFillColorWithColor(ctx, fillColor.CGColor);
CGContextDrawPath(ctx, kCGPathFill);

UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;

}

#pragma mark - UIPopoverBackgroundView Overrides
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
self.backgroundColor = [UIColor clearColor];

//TODO: update with border image view
UIImageView *arrowImageView = [[UIImageView alloc] initWithFrame:CGRectZero];
self.arrowImageView = arrowImageView;
[self addSubview:self.arrowImageView];

}
return self;
}

+ (CGFloat)arrowBase
{
return kArrowBase;
}

+ (CGFloat)arrowHeight
{
return kArrowHeight;
}

+ (UIEdgeInsets)contentViewInsets
{
return UIEdgeInsetsMake(kBorderInset, kBorderInset, kBorderInset, kBorderInset);
}

+ (BOOL)wantsDefaultContentAppearance
{
return NO;
}

- (void)layoutSubviews
{
[super layoutSubviews];

//TODO: test for arrow UIPopoverArrowDirection
CGSize arrowSize = CGSizeMake([[self class] arrowBase], [[self class] arrowHeight]);
self.arrowImageView.image = [self drawArrowImage:arrowSize];

self.arrowImageView.frame = CGRectMake(((self.bounds.size.width - arrowSize.width)- kBorderInset), 0.0f, arrowSize.width, arrowSize.height);

}