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我遇到了我正在实现的视图的问题。UISwipeGestureRecognizer调用两次
这是一个显示CATiledLayer中的pdf页面的视图。该平铺视图位于UISCrollView中。
我将视图控制为“ZoomingPDFView”苹果示例。我做了一些修改，以便在滚动未启用时识别滑动手势，并在本网站的各种线程和问题中提供建议。那时手势被称为一次。但是，因为我需要分离视图并委托滑动来缓存页面并做一个多功能视图，所以我创建了一个视图控制器来处理滑动手势，并且页面加载方法提高了pdf视图的性能。
现在我已经看到一侧和控制器在另一侧，滑动手势被检测两次，我甚至无法得出问题的线索。
这是控制台输出
2010-11-19 11:45:08.370 ZoomingPDFViewerForIPad[20327:207] initWithFrame and page
2010-11-19 11:45:08.530 ZoomingPDFViewerForIPad[20327:207] drawPage
2010-11-19 11:45:08.531 ZoomingPDFViewerForIPad[20327:207] scale: 1.000000
2010-11-19 11:45:08.531 ZoomingPDFViewerForIPad[20327:207] pdf scale: 1.290062
2010-11-19 11:45:08.532 ZoomingPDFViewerForIPad[20327:207] pdf initial scale: 1.290062
2010-11-19 11:45:15.488 ZoomingPDFViewerForIPad[20327:207] left
2010-11-19 11:45:15.489 ZoomingPDFViewerForIPad[20327:207] left
2010-11-19 11:45:15.490 ZoomingPDFViewerForIPad[20327:207] initWithFrame and page
2010-11-19 11:45:15.538 ZoomingPDFViewerForIPad[20327:207] drawPage
2010-11-19 11:45:15.538 ZoomingPDFViewerForIPad[20327:207] scale: 1.000000
2010-11-19 11:45:15.539 ZoomingPDFViewerForIPad[20327:207] pdf scale: 1.290062
2010-11-19 11:45:15.539 ZoomingPDFViewerForIPad[20327:207] pdf initial scale: 1.290062
2010-11-19 11:45:15.540 ZoomingPDFViewerForIPad[20327:1a07] initWithFrame and page
2010-11-19 11:45:15.541 ZoomingPDFViewerForIPad[20327:5f07] initWithFrame and page
2010-11-19 11:45:15.593 ZoomingPDFViewerForIPad[20327:1a07] drawPage
2010-11-19 11:45:15.594 ZoomingPDFViewerForIPad[20327:1a07] scale: 1.000000
2010-11-19 11:45:15.594 ZoomingPDFViewerForIPad[20327:1a07] pdf scale: 1.290062
2010-11-19 11:45:15.595 ZoomingPDFViewerForIPad[20327:1a07] pdf initial scale: 1.290062
2010-11-19 11:45:15.695 ZoomingPDFViewerForIPad[20327:5f07] drawPage
2010-11-19 11:45:15.704 ZoomingPDFViewerForIPad[20327:5f07] scale: 1.000000
2010-11-19 11:45:15.707 ZoomingPDFViewerForIPad[20327:5f07] pdf scale: 1.290062
2010-11-19 11:45:15.713 ZoomingPDFViewerForIPad[20327:5f07] pdf initial scale: 1.290062
下面的代码：
#import <UIKit/UIKit.h>
@class TiledPDFView;
@protocol PDFScrollViewDelegate;
@interface PDFScrollView : UIScrollView <UIScrollViewDelegate> {
// The TiledPDFView that is currently front most
TiledPDFView *pdfView;
// The old TiledPDFView that we draw on top of when the zooming stops
TiledPDFView *oldPDFView;
// A low res image of the PDF page that is displayed until the TiledPDFView
// renders its content.
UIImageView *backgroundImageView;
id<PDFScrollViewDelegate,NSObject> pdfViewDelegate;
// current pdf zoom scale
CGFloat pdfScale;
CGPDFPageRef page;
CGPDFDocumentRef pdf;
CGFloat initialScale;
TiledPDFView *initialTiledView;
int currentPage;
int pageCount;
UITapGestureRecognizer *doubleTap,*twoFingerDoubleTap;
UISwipeGestureRecognizer *rightSwipe, *leftSwipe;
}
@property (nonatomic,retain) id<PDFScrollViewDelegate> pdfViewDelegate;
-(id)initWithFrame:(CGRect)rect;
-(id)initWithFrame:(CGRect)frame andPDFPage:(CGPDFPageRef)aPage;
-(void)enableGestures;
-(void)drawPage;
@end
@implementation PDFScrollView
@synthesize pdfViewDelegate;
….
-(void)enableGestures{
leftSwipe = [[UISwipeGestureRecognizer alloc ]initWithTarget:self action:@selector(handleRightSwipe:)];
leftSwipe.direction = UISwipeGestureRecognizerDirectionRight;
[self addGestureRecognizer:leftSwipe];
//add right swipe
rightSwipe = [[UISwipeGestureRecognizer alloc ]initWithTarget:self action:@selector(handleLeftSwipe:)];
rightSwipe.direction = UISwipeGestureRecognizerDirectionLeft;
[self addGestureRecognizer:rightSwipe];
doubleTap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(handleDoubleTap:)];
doubleTap.numberOfTapsRequired =2;
doubleTap.numberOfTouchesRequired =1;
[self addGestureRecognizer:doubleTap];
twoFingerDoubleTap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(handleTwoFingerDoubleTap:)];
twoFingerDoubleTap.numberOfTapsRequired =2;
twoFingerDoubleTap.numberOfTouchesRequired =2;
[self addGestureRecognizer:twoFingerDoubleTap];
}
// some more code
@end
#import <UIKit/UIKit.h>
#import "PDFScrollViewDelegate.h"
@class TiledPDFView;
@interface ZoomingPDFViewerForIPadViewController : UIViewController <UIScrollViewDelegate,PDFScrollViewDelegate> {
CGPDFPageRef page;
CGPDFDocumentRef pdf;
NSInteger currentPage;
NSInteger pageCount;
PDFScrollView *myScrollView;
PDFScrollView *previousPage;
PDFScrollView *nextPage;
}
-(id)initWithResourcePath:(NSString*)path ;
-(void)loadNextPage;
-(void)loadPreviousPage;
@end
@implementation ZoomingPDFViewerForIPadViewController
// some more code
#pragma mark -
#pragma mark PDFScrollViewDelegate methods
/*
called when user swipes right on the view
*/
-(void)viewDetectedRightSwipe:(PDFScrollView*)pdfScrollView withGesture:(UISwipeGestureRecognizer*)recognizer {
NSLog(@"right");
if (currentPage>1){
//decreate page counter
currentPage--;
// release old next page
if(nextPage){
[nextPage release];
}
// set the actual page as the next one
nextPage = [myScrollView retain];
// remove the view from the actual view
[myScrollView removeFromSuperview];
// check if the previous page is loaded
if(!previousPage)
[self loadPreviousPage];
// set the previouse page as the actual page
myScrollView = previousPage;
myScrollView.pdfViewDelegate = self;
//[myScrollView drawPage];
// load a new previous page
//[NSThread detachNewThreadSelector:@selector(loadNextPage) toTarget:self withObject:nil];
//[self loadNextPage];
}
}
/*
called when user swipes left on the view
*/
-(void)viewDetectedLeftSwipe:(PDFScrollView*)pdfScrollView withGesture:(UISwipeGestureRecognizer*)recognizer{
NSLog(@"left");
// if the end of the document isn't reached
if (currentPage<pageCount){
//increment current page
currentPage++;
// if a previous page has been loaded release it
if (previousPage) {
[previousPage release];
}
// assing the actual view to as a previous page and retain it before it gets release by superview
previousPage = [myScrollView retain];
// remove the view from the super view
[myScrollView removeFromSuperview];
// if a next page hasn't beeen loaded yet, load it on this thread
if (!nextPage)
[self loadNextPage];
// assign the next page as the current page
myScrollView = nextPage;
// put the current page the delegate
myScrollView.pdfViewDelegate = self;
// add the current page to the super view
[[self view] addSubview:myScrollView];
// load a next page.
[NSThread detachNewThreadSelector:@selector(loadNextPage) toTarget:self withObject:nil];
//[self loadNextPage];
}
}
/*
called when the user taps the screen
*/
-(void)viewDetectedTapping:(PDFScrollView*)pdfScrollView withGesture:(UITapGestureRecognizer*)recognizer {
NSLog(@"tapped");
[myScrollView setZoomScale:1.0f animated:YES];
}
-(void)loadNextPage {
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
CGPDFPageRef aPage = CGPDFDocumentGetPage(pdf, currentPage+1);
nextPage = [[PDFScrollView alloc] initWithFrame:myScrollView.frame andPDFPage:aPage ];
[pool release];
}
-(void)loadPreviousPage {
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
CGPDFPageRef aPage = CGPDFDocumentGetPage(pdf, currentPage-1);
previousPage = [[PDFScrollView alloc] initWithFrame:myScrollView.frame andPDFPage:aPage];
[pool release];
}
@end
这是举手投足引起的代码。
-(void)handleRightSwipe:(UIGestureRecognizer*)gesture {
if ([pdfViewDelegate respondsToSelector:@selector(viewDetectedRightSwipe:withGesture:)]) {
UISwipeGestureRecognizer *swipe = (UISwipeGestureRecognizer*)gesture;
[pdfViewDelegate viewDetectedRightSwipe:self withGesture:swipe];
}
}
-(void)handleLeftSwipe :(UIGestureRecognizer*)gesture{
if ([pdfViewDelegate respondsToSelector:@selector(viewDetectedLeftSwipe:withGesture:)]) {
UISwipeGestureRecognizer *swipe= (UISwipeGestureRecognizer*)gesture;
[pdfViewDelegate viewDetectedLeftSwipe:self withGesture:swipe];
}
}
预先感谢您的时间
请显示handleRightSwipe和/或handleLeftSwipe的代码。 – Anna 2010-11-19 15:09:31
我刚刚做了一个编辑。谢谢（顺便提一下，很棒的用户名） – Pacu 2010-11-20 19:39:48