从字符串中检索图像URL

Question

我正在解析一个xml文件,我可以NSLog解析,但我的问题是我需要从这个"字符串"获取图像url!

<p>
 <a href="http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex43.jpg"><img class="alignnone size-thumbnail wp-image-81" title="ex4" src="http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex43-150x150.jpg" alt="" width="150" height="150" /></a>
 <a href="http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex32.jpg"><img class="alignnone size-thumbnail wp-image-80" title="ex3" src="http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex32-150x150.jpg" alt="" width="150" height="150" /></a>
 <a href="http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex23.jpg"><img class="alignnone size-thumbnail wp-image-79" title="ex2" src="http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex23-150x150.jpg" alt="" width="150" height="150" /></a>
 <a href="http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex12.jpg"><img class="alignnone size-thumbnail wp-image-71" title="ex1" src="http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex12-150x150.jpg" alt="" width="150" height="150" /></a>
 </p>

对不起普通代码:)

我用来提取网址的是这段代码,但它不起作用:

   NSRange start = [item.imageGallery       rangeOfString:@"http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/"];
    NSRange end = [item.imageGallery rangeOfString:@"\" "];

    int rangeLength = (int)(end.location - start.location);

    NSString *hrefString = [[NSString alloc] initWithString:[item.imageGallery substringWithRange:NSMakeRange(start.location, rangeLength)]];
    NSLog(@"image url = %@",hrefString);

Answer 1

使用正则表达式: "src=\"([^\"]+)\""

这是一些示例代码:

NSString *searchedString = @""  
    @"<p>"
    @"<a href=\"http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex43.jpg\"><img class=\"alignnone size-thumbnail wp-image-81\" title=\"ex4\" src=\"http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex43-150x150.jpg\" alt=\"\" width=\"150\" height=\"150\" /></a>"
    @"<a href=\"http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex32.jpg\"><img class=\"alignnone size-thumbnail wp-image-80\" title=\"ex3\" src=\"http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex32-150x150.jpg\" alt=\"\" width=\"150\" height=\"150\" /></a>"
    @"<a href=\"http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex23.jpg\"><img class=\"alignnone size-thumbnail wp-image-79\" title=\"ex2\" src=\"http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex23-150x150.jpg\" alt=\"\" width=\"150\" height=\"150\" /></a>"
    @"<a href=\"http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex12.jpg\"><img class=\"alignnone size-thumbnail wp-image-71\" title=\"ex1\" src=\"http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex12-150x150.jpg\" alt=\"\" width=\"150\" height=\"150\" /></a>"
    @"</p>";
NSRange rangeOfString = NSMakeRange(0, [searchedString length]);
//NSLog(@"searchedString: %@", searchedString);

NSString *pattern = @"src=\"([^\"]+)\"";
NSError* error = nil;

NSRegularExpression* regex = [NSRegularExpression regularExpressionWithPattern:pattern options:0 error:&error];
NSArray *matchs = [regex matchesInString:searchedString options:0 range:rangeOfString];
    for (NSTextCheckingResult* match in matchs) {
        NSLog(@"url: %@", [searchedString substringWithRange:[match rangeAtIndex:1]]);
    }

NSLog输出:

url: http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex43-150x150.jpg
url: http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex32-150x150.jpg
url: http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex23-150x150.jpg
url: http://www.bubblesurprise.com/WPRESS_APP/wp-content/uploads/2012/02/ex12-150x150.jpg