iPhone UITableView异步加载图片 （动态加载图片）

//-----------方法1----------------

//AsyncImageView.h

#import <UIKit/UIKit.h>

@interface AsyncImageView : UIView {

 

NSURLConnection*connection;

 

NSMutableData*data;

}

 

- (void)loadImageFromURL:(NSURL*)url;

@end

 

 

//AsyncImageView.m

 

#import "AsyncImageView.h"

 

 

@implementation AsyncImageView

 

 

- (id)initWithFrame:(CGRect)frame {

    if ((self = [super initWithFrame:frame])) {

        // Initialization code

    }

    return self;

}

 

 

- (void)loadImageFromURL:(NSURL*)url {

 

if(connection!=nil) { 

[connection release];

}

if(data!=nil) {

[data release];

}

 

NSURLRequest* request = [NSURLRequest requestWithURL:url

cachePolicy:NSURLRequestUseProtocolCachePolicy

timeoutInterval:30.0];

 

connection= [[NSURLConnection alloc] initWithRequest:request delegate:self];

 

//TODO error handling, what if connection is nil?

}

 

- (void)connection:(NSURLConnection*)theConnection

 

didReceiveData:(NSData*)incrementalData {

 

if(data==nil) {

data=[[NSMutableData alloc]initWithCapacity:2048];

    }

 

    [data appendData:incrementalData];

}

 

- (void)connectionDidFinishLoading:(NSURLConnection*)theConnection {

 

    [connection release];

 

connection=nil;

 

if([[self subviews]count]>0) {

 

        [[[self subviews] objectAtIndex:0] removeFromSuperview];

 

    }

 

UIImageView*imageView= [[[UIImageView alloc]initWithImage:[UIImage imageWithData:data]]autorelease];

 

imageView.contentMode=UIViewContentModeScaleAspectFit;

 

imageView.autoresizingMask= (UIViewAutoresizingFlexibleWidth||UIViewAutoresizingFlexibleHeight);

 

    [self  addSubview:imageView];

 

imageView.frame=self.bounds;

 

    [imageView setNeedsLayout];

 

    [self setNeedsLayout];

 

    [data release];

 

data=nil;

 

}

 

- (UIImage*) image {

 

UIImageView *iv = [[self subviews]objectAtIndex:0];

 

return[iv image];

 

}

 

 

/*

// Only override drawRect: if you perform custom drawing.

// An empty implementation adversely affects performance during animation.

- (void)drawRect:(CGRect)rect {

    // Drawing code

}

*/

 

- (void)dealloc {

    [connection cancel];

    [connection release];

    [data release];

    [super dealloc];

}

 

 

@end

 

 

在uitableview 中调用

 

// Customize the appearance of table view cells.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    

    static NSString *CellIdentifier = @"Cell";

  

 

 UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) {

        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier]autorelease];

 

}else{

 

AsyncImageView* oldImage = (AsyncImageView*)[cell.contentView viewWithTag:999];

[oldImage removeFromSuperview];

    }

 

CGRect frame;

frame.size.width=150; frame.size.height=75;

frame.origin.x=20; frame.origin.y=5;

 

AsyncImageView *asyncImage = [[[AsyncImageView alloc] initWithFrame:frame] autorelease];

asyncImage.tag =999;

//NSString *strUrl = [imagesArray objectAtIndex:indexPath.row]

NSString *strUrl = @"http://merrimusings.mu.nu/archives/images/groundhog2.jpg";

NSURL *url = [NSURL URLWithString:strUrl];

[asyncImage loadImageFromURL:url];

//[cell.contentView addSubview:asyncImage];

[cell addSubview:asyncImage];

 

//cell.textLabel.text = [dataArray objectAtIndex:indexPath.row];

 

cell.textLabel.text = @"ok";

 

cell.textLabel.font = font;

cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;

 

    return cell;

}

 

 

//--------------方法2-------------

 

 

// Customize the appearance of table view cells.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    

    static NSString *CellIdentifier = @"Cell";

  

 

 

 UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) {

        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefaultreuseIdentifier:CellIdentifier] autorelease];

 

}

 

[NSThread detachNewThreadSelector:@selector(updateImageForCellAtIndexPath:) toTarget:selfwithObject:indexPath];

 

 

UIFont *font = [UIFont fontWithName:@"Helvetica" size:17];

//cell.textLabel.text = [dataArray objectAtIndex:indexPath.row];

 

 

cell.textLabel.text = @"ok";

 

 

cell.textLabel.font = font;

 

 

cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;

 

    return cell;

}

 

 

- (void)updateImageForCellAtIndexPath:(NSIndexPath *)indexPath{

 

    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

    UIImage *image = [self getImageForCellAtIndexPath:indexPath];

if (image) {

NSLog(@"image ok %d",indexPath.row);

}

    UITableViewCell *cell = [self.tbView cellForRowAtIndexPath:indexPath];

 

CGRect rect;

UIImageView *iv = [[UIImageView alloc] initWithFrame:CGRectMake(KNewCollectionImageViewX+5,kTopButtonMargin, KShopCellImageViewWidth, KShopCellImageViewHeight)];

iv.tag = KImageViewTag;

iv.backgroundColor = [UIColor clearColor];

rect = iv.frame;

//iv.image = image;

[cell addSubview:iv];

//cell.imageView.image = image;

    //[cell.imageView performSelectorOnMainThread:@selector(setImage:) withObject:image waitUntilDone:NO];

[iv performSelectorOnMainThread:@selector(setImage:) withObject:image waitUntilDone:NO];

[iv release];

    //[image release];

    [pool release];

}

 

-(UIImage *)getImageForCellAtIndexPath:(NSIndexPath *)indexPath{

 

   // id path = [[dataArray objectAtIndex:indexPath.row] objectForKey:@"image"];

//id path = [imageArray objectAtIndex:indexPath.row];

//id path = @"http://merrimusings.mu.nu/archives/images/groundhog2.jpg";

 

NSString *path = @"http://merrimusings.mu.nu/archives/images/groundhog2.jpg";

 

NSURL *url = [NSURL URLWithString:path];

NSData *data = [NSData dataWithContentsOfURL:url];

//UIImage *image = [[UIImage alloc] initWithData:data cache:NO];

 

   // NSURL *url = [NSURL URLWithString:path];

    //NSData *data = [NSData dataWithContentsOfURL:url];

    //UIImage *image = [[UIImage alloc] initWithData:data cache:NO];

//UIImage *image = [[UIImage alloc] initWithData:data cache:NO]; 

 

UIImage *image = [UIImage imageWithData:data];

 

if (image) {

NSLog(@"%@",path);

}

 

    return image;

}