如何在iphone應用程序中的UITableCell中加載圖像

Question

我開發了一個RSS應用程序。在我的表格單元格中，我顯示的圖像是從RSS feed和Title中的圖像鏈接中檢索的。 圖像已成功加載，但問題是它掛起我的應用程序。 有沒有辦法在後臺加載圖片。 我現在的代碼是。

int blogEntryIndex1 = [indexPath indexAtPosition: [indexPath length] -1]; 
     imgstring=[[blogEntries objectAtIndex: blogEntryIndex1] objectForKey: @"image"]; 
NSURL *url = [NSURL URLWithString:imgstring]; 
    NSData *data = [NSData dataWithContentsOfURL:url]; 
    UIImage *img = [[UIImage alloc] initWithData:data]; 
    cell.imageView.image=[img autorelease]; 

任何想法請，在此先感謝...

Answer 1

轉播......你也應該看看懶加載表通過蘋果的示例代碼http://developer.apple.com/iphone/library/samplecode/LazyTableImages/Introduction/Intro.html

更新另一個例子在這裏：http://www.markj.net/iphone-asynchronous-table-image/

Answer 2

並且從Apple看看這個文件。

http://developer.apple.com/iphone/library/documentation/cocoa/Conceptual/URLLoadingSystem/URLLoadingSystem.html

大多數我用NSURLConnection下載東西的時候。

Answer 3

那麼傢伙，我已經做了它的代碼是...

- (void) loadImage:(id)object { 
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; 

// Get the data to pass in 
NSDictionary *dict = (NSDictionary *)object; 

// Get the cell and the image string 
NSString *imgstring = [dict objectForKey:@"imgstring"]; 
MyfirstCell *cell = [dict objectForKey:@"cell"]; 

NSURL *url = [NSURL URLWithString:imgstring]; 
NSData *data = [NSData dataWithContentsOfURL:url]; 
UIImage *img = [[UIImage alloc] initWithData:data]; 
    cell.myimnage.image = img; 
[pool release]; 

}

我會打電話給上面的方法在我的代碼...

if(searching) { 
     //cell.textLabel.text = [copyListOfItems objectAtIndex:indexPath.row]; 
     int blogEntryIndex = [indexPath indexAtPosition: [indexPath length] -1]; 
     // Tell your code to load the image for a cell in the background 
     NSString *imgstring =[[blogEntries objectAtIndex: blogEntryIndex] objectForKey: @"image"]; 
     NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:cell, @"cell", imgstring, @"imgstring", nil]; 
     [self performSelectorInBackground:@selector(loadImage:) withObject:dict]; 
     //background code end here.. 

感謝deanWombourne誰給了我這個代碼....

Answer 4

你可以這樣使用：

((UIImageView *)cell.backgroundView).image = bgImage; 
((UIImageView *)cell.selectedBackgroundView).image = bgImage;