ios 团购信息客户端demo(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

 

#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

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

 

#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

 

 

#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

 

 

#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

 

//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

 

//利用缓存保存图片