OpenFlow（效果图）中文实用详解

当用户界面需要按页面显示图片时，使用OpenFlow库提供的功能，将要显示的用户界面图片分页进行显示会使编程工作变得非常快捷。该库提供了与OS X桌面Finder程序相同的视觉效果，如图3-46所示就是一个使用OpenFlow库逐页进行图片显示的程序，用户按下屏幕即可进行左右滚动显示，双击图片即可对当前显示的图片进行选取操作。

// RootViewController.m

程序在视图控制器的viewDidAppear()中使用refreshCoverFlow()函数初始化OpenFlow库，通过setNumberOfImages()函数设置图片数量，代码如下。

- (void)refreshCoverFlow{

CGRect bounds = [[UIScreen mainScreen]bounds];

AFOpenFlowView *coverFlowView =(AFOpenFlowView*)[self.view viewWithTag:kTagCoverflow];

if(coverFlowView != nil)

[coverFlowView removeFromSuperview];

coverFlowView = [[AFOpenFlowView alloc]initWithFrame:CGRectMake(0, -30, bounds.size.width,COVERFLOWHEIGHT)];

coverFlowView.dataSource = self;

coverFlowView.viewDelegate = self;

coverFlowView.defaultImage = [selfdefaultImage];

coverFlowView.tag = kTagCoverflow;

[self.view addSubview:coverFlowView];

NSInteger count = [self numberOfAnimals];

[coverFlowView setNumberOfImages:count];

//...

[coverFlowView release];

}

并在loadView()中初始化图片，将图片从资源中加载并保存在一个NSMutableArray类型的变量imageArray中，代码如下。

- (BOOL)doAddAnimal:(NSString *)name Image:(NSString*)imageName{

UIImage *image = [UIImage imageNamed:imageName];

if(image == nil) return FALSE;

CGSize size = CGSizeMake(179,208);

[imageArray addObject:[self resizeImage:imagescaledToSize:size]];

return TRUE;

}

在OpenFlow库的requestImageForIndexdelegate方法中直接通过NSMutableArray的索引作为OpenFlow库的图片索引，并通过该索引设置和获取具体图片，代码如下。

// PageViewController.m

- (void)openFlowView:(AFOpenFlowView *)openFlowViewrequestImageForIndex: (int)index{

UIImage *image = [imageArrayobjectAtIndex:index];

[openFlowView setImage:imageforIndex:index];

}

笔者在OpenFlow库AFOpenFlowView.m文件的touchesEnded()函数中增加了双击回调接口，以便在用户双击图片时通知库的调用者，代码如下。

//AFOpenFlowView.m

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{

if(((UITouch *)[touches anyObject]).tapCount ==2){

if ([self.viewDelegate respondsToSelector:@selector(openFlowView:coverViewDoubleClick:)])

[self.viewDelegateopenFlowView:self coverViewDoubleClick:selectedCoverView.number];

}

[supertouchesEnded:touches withEvent:event];

}

库的调用者RootViewController类通过接口函数coverViewDoubleClick()即可处理用户双击事件，代码如下。

- (void)openFlowView:(AFOpenFlowView *)openFlowViewcoverViewDoubleClick:(int)index{

NSLog(@"coverViewDoubleClick called!");

[self showPaintingViewController];}