Question

“ - [NSMutableArray insertObject：atIndex：]：尝试将nil对象插入0'”

如果我使用硬编码路径（代码中的“路径”），则会正确添加图像。当我从RSS提要中检索相同的URL时，它不起作用（上面的错误）。

我尝试使用简单的相等性检查来检查URL，但它表明它们不相等，尽管它们在调试器输出中看起来是这样。

对内存管理的任何见解也会有所帮助。我来自Flash工作世界和一个菜鸟到xcode（抱歉）。我知道我需要停止将内存管理视为事后的想法......

-

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self prepareGalleryLoad]; //sets up coverflow, waiting for data

    NSString *xmlpath =     @"http://mydomain.com/gallery3/index.php/rss/feed/gallery/album/12";

xmlreader = [[XMLReader alloc] init];
[xmlreader parseXMLFileAtURL:xmlpath];


NSMutableArray *imagearray = [[NSMutableArray alloc]init]; //array of images
NSMutableArray *imagearraycaptions = [[NSMutableArray alloc]init]; //array of captions for images

NSString *path;  
NSString *pathfromrss;  

UIImage *tempimage;

for (int y = 0; y < [xmlreader.stories count]; y++){
    [imagearraycaptions addObject:[[xmlreader.stories objectAtIndex:y] objectForKey:@"title"]];
    path = @"http://mydomain.com/gallery3/var/resizes/College-of-Nursing-and-Health-Studies/health10.jpg?m=1299713266";    
    pathfromrss = [NSString stringWithFormat:@"%@",[[xmlreader.stories objectAtIndex:y] objectForKey:@"link"]];

    //DIAGNOSTIC check of path vs path temp.
    if (path == pathfromrss){
        NSLog(@"path is equal");
    }else{
        NSLog(@"path is not equal");
        NSLog(@"%@",path);
        NSLog(@"%@",pathfromrss);
    }

    //END DIAGNOSTIC path check

    tempimage = [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:path]]];

    //tempimage is NIL when using "pathfromrss", works fine with "path"
    if(tempimage){
        [imagearray addObject:tempimage];
    }
}

coverstext = imagearraycaptions; //coverflow uses this
covers = imagearray; //coverflow uses this

[self finishGalleryLoad];

}

Answer 1

一位朋友帮助我找到答案。 RSS提要包括我没有在调试器输出中捕获的换行符。用以下方法清理它们：

for (int y = 0; y < [xmlreader.stories count]; y++){
    pathfromrss = [NSString stringWithFormat:@"%@",[[xmlreader.stories objectAtIndex:y] objectForKey:@"link"]];
    [coverflowdescription setText:pathfromrss];

    NSString *cleanurl = [pathfromrss stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
    NSData *mydata = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:cleanurl]];

    UIImage *tempimage = [[UIImage alloc] initWithData:mydata];
    if(tempimage){
        [imagearraycaptions addObject:[[xmlreader.stories objectAtIndex:y] objectForKey:@"title"]];
        [imagearray addObject:tempimage];
    }
}

Xcode - 从RSS提要URL问题向阵列添加UIImages

1 个答案: