我有一个应用程序,我正在写这将需要下载很多图像,可能是10,000。现在我可以在内存不足和应用程序崩溃之前达到大约3000,这取决于图像文件的大小。我正在下载后台线程并向用户显示进度。下载大量图片ipad - 内存泄露?
我写了一个帮助类,我正在访问做这个,并想知道如果这是我的问题所在,我只是泄漏内存。
这里是我的循环,下载图像 - 这是在后台线程上运行,这是所有内部的NSAutoReleasePool:
for (int j=0; j < [items count]; j++)
{
ImagesHelper *helper = [[ImagesHelper alloc]init];
[helper downloadImages: [[items objectAtIndex:j] valueForKey:@"ItemSKU"] withManufacturer: [[manufacturers objectAtIndex:i] ManufacturerID]];
[helper release];
if (j%50==0) { //this notifies the user of progress
statusMessage = [NSString stringWithFormat:@"Downloading images: %@.jpg (%d of %d)", [[items objectAtIndex:j] valueForKey:@"ItemSKU"],j+1, [items count]];
[self performSelectorOnMainThread:@selector(setStatus) withObject:nil waitUntilDone:YES];
}
}
这里是我的助手类:
-(void) downloadImages:(NSString *)ItemSKU withManufacturer: (NSString *) aManufacturerID{
NSData *imageData = nil;
NSData *imageDataLarge=nil;
NSString *fileName = [NSString stringWithFormat:@"%@_tn.jpg", [ItemSKU stringByReplacingOccurrencesOfString:@" " withString:@""]];
NSString *fileNameLarge = [NSString stringWithFormat:@"%@_lg.jpg", [ItemSKU stringByReplacingOccurrencesOfString:@" " withString:@""]];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsPath = [paths objectAtIndex:0];
NSString *savePath = [documentsPath stringByAppendingPathComponent:fileName];
NSString *savePathLarge = [documentsPath stringByAppendingPathComponent:fileNameLarge];
/* go get the image */
NSString *URL = [NSString stringWithFormat:kProductImagesURL,aManufacturerID, fileName];
NSString *URLLarge = [NSString stringWithFormat:kProductImagesURL,aManufacturerID, fileNameLarge];
NSLog(@"Going to get the file: %@",URL);
imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:URL]];
if (imageData!=nil) {
[imageData writeToFile:savePath atomically:YES];
}
imageDataLarge = [NSData dataWithContentsOfURL:[NSURL URLWithString:URLLarge]];
if (imageDataLarge!=nil) {
[imageDataLarge writeToFile:savePathLarge atomically:YES];
}
imageData = nil;
imageDataLarge=nil;
}
仍在尝试去了解一些这些概念。
是的,它看起来像我回到主线程后,一切都得到释放。我将不得不将它们分成小块并运行一系列后台线程。 – Slee 2010-09-14 01:00:30
+1表示操作队列。它是为这样的东西而建造的。 – 2010-09-14 02:54:22