[iPhone中级] iPhone团购信息客户端的开发 (三)

接上二篇的内容，今天我们就来介绍一下如何将解析出来的数据放入AQGridView中显示出来，因为我们的工程中已经将AQGridView导入了，所以我们在KKFirstViewController中直接可以引用

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#import <UIKit/UIKit.h>

#import "ASIHTTPRequest.h"

#import "AQGridView.h"

@interface KKFirstViewController : UIViewController<ASIHTTPRequestDelegate, AQGridViewDelegate, AQGridViewDataSource>

@property(nonatomic, retain)AQGridView *gridView;

@end

这里加入了AQGridViewDelegate和AQGridViewDataSource这两个委托，简单一点我们可以把AQGridView看成UITableView，同样的道理，一个是数据源的方法，一个就是选中的方法

然后就是

在-(void)viewDidLoad这个方法中，我们加入了

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self.gridView = [[AQGridView alloc] initWithFrame:CGRectMake(0, 0, 320, 460)];

self.gridView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

self.gridView.autoresizesSubviews = YES;

self.gridView.delegate = self;

self.gridView.dataSource = self;

[self.view addSubview:gridView];

将当前的gridView加入主视图中

接着还有两个方法一定需要实现的

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#pragma mark AQGridViewDataSource

//总共有的Item

-(NSUInteger)numberOfItemsInGridView:(AQGridView *)gridView{

return [arrays count];

}

//每个Item

-(AQGridViewCell *)gridView:(AQGridView *)aGridView cellForItemAtIndex:(NSUInteger)index{

static NSString *identifier = @"PlainCell";

GridViewCell *cell = (GridViewCell *)[aGridView dequeueReusableCellWithIdentifier:identifier];

if(cell == nil){

cell = [[GridViewCell alloc] initWithFrame:CGRectMake(0, 0, 160, 123) reuseIdentifier:identifier];

}

//取得每一个字典

NSDictionary *dict = [arrays objectAtIndex:index];

[cell.captionLabel setText:[dict objectForKey:kName_Title]];

return cell;

}

//每个显示框大小

-(CGSize)portraitGridCellSizeForGridView:(AQGridView *)gridView{

return CGSizeMake(160, 123);

}

这里还少一个类，就是GridView，这个类继承了AQGridViewCell，里面就是我们单独要显示的一个Item

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#import "AQGridViewCell.h"

@interface GridViewCell : AQGridViewCell

@property(nonatomic, retain)UIImageView *imageView;

@property(nonatomic, retain)UILabel *captionLabel;

@end

图片显示的是团购信息中的图片，还有一个是文本

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#import "GridViewCell.h"

@implementation GridViewCell

@synthesize imageView,captionLabel;

- (id)initWithFrame:(CGRect)frame reuseIdentifier:(NSString *)reuseIdentifier

{

self = [super initWithFrame:frame reuseIdentifier:reuseIdentifier];

if (self) {

UIView *mainView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 160, 123)];

[mainView setBackgroundColor:[UIColor clearColor]];

UIImageView *frameImageView = [[UIImageView alloc] initWithFrame:CGRectMake(9, 4, 142, 117)];

[frameImageView setImage:[UIImage imageNamed:@"tab-mask.png"]];

self.imageView = [[UIImageView alloc] initWithFrame:CGRectMake(13, 8, 135, 84)];

self.captionLabel = [[UILabel alloc] initWithFrame:CGRectMake(13, 92, 127, 21)];

[captionLabel setFont:[UIFont systemFontOfSize:14]];

[mainView addSubview:imageView];

[mainView addSubview:frameImageView];

[mainView addSubview:captionLabel];

[self.contentView addSubview:mainView];

}

return self;

}

@end

这里面定义了三个控件，两个控件是我们要传入的数据，一个图片，一个文本，还有一个就是我们单独Item的背景

做完这一些，运行一下，我们就可以看到有文字信息的效果了，但还没有加入图片显示功能，从这里我们就要考虑了，图片是我们划动的时候再加载呢还是一次性加载呢，考虑到效果和数据流量，我们还是用异步来加载数据，这就需要加入缓存的功能了，我们用一个NSMutableArray来实现缓存。

看一下代码呢，这代码也是参考了别人写的

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//缓存图片

-(UIImage *)cachedImageForUrl:(NSURL *)url{

id cacheObject = [self.cachedImage objectForKey:url];

if (cacheObject == nil) {

//添加占位符

[self.cachedImage setObject:@"Loading..." forKey:url];

ASIHTTPRequest *picRequest = [ASIHTTPRequest requestWithURL:url];

picRequest.delegate = self;

picRequest.didFinishSelector = @selector(didFinishRequestImage:);

picRequest.didFailSelector = @selector(didFailRequestImage:);

//加入队列

[self.queue addOperation:picRequest];

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

}else if(![cacheObject isKindOfClass:[UIImage class]]){

cacheObject = nil;

}

return cacheObject;

}

//完成图片下载，并加入缓存

-(void)didFinishRequestImage:(ASIHTTPRequest *)request{

NSData *imageData = [request responseData];

UIImage *image = [UIImage imageWithData:imageData];

if (image != nil) {

[self.cachedImage setObject:image forKey:request.url];

[self.gridView reloadData];

}

[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;

}

//下载失败

-(void)didFailRequestImage:(ASIHTTPRequest *)request{

NSLog(@"Error download Image %@", [request error]);

//从当前缓存中移除

[self.cachedImage removeObjectForKey:request.url];

[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;

}

最后我们在Cell中加入显示图片的代码就可以了，就实现了异步加载图片

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//利用缓存保存图片

[cell.imageView setImage:[self cachedImageForUrl:[NSURL URLWithString:[dict objectForKey:kName_Img]]]];

好了，这个程序中主要介绍了AQGridView库，MBProgressHUD，KissXML，ASIHttpRequest这几个库，综合利用各个类库将可以使我们的程序美观，也可以缩短我们的开发周期。好了，谢谢大家有耐心看完。这里提供了源码下载

程序源码