比较两个网址（iPhone）

Question

你好朋友，我想比较两个网址在xcode（目标c） 怎么可能？

-(IBAction) download{ 
NSURL *url1 = [NSURL URLWithString:@"http://www.google.com/images?hl=en&q=flowers&bav=on.1,or.&um=1&ie=UTF-8&source=og&sa=N&tab=wi&biw=1512&bih=677"]; 
NSURL *url2 = [NSURL URLWithString:@"http://www.google.com/imgres?imgurl=http://www.missouriplants.com/Yellowopp/Helianthus_divaricatus_flowers.jpg&imgrefurl=http://www.missouriplants.com/Yellowopp/Helianthus_divaricatus_page.html&usg=__W-J2oEuDpbxhlU4plpC3JHP3wU0=&h=449&w=450&sz=41&hl=en&start=0&zoom=1&tbnid=axuO9VsiGsWlCM:&tbnh=131&tbnw=134&ei=h9tsTebwLc3irAeW1Kz7Bg&prev=/images%3Fq%3Dflowers%26um%3D1%26hl%3Den%26sa%3DN%26biw%3D1512%26bih%3D677%26tbs%3Disch:1&um=1&itbs=1&iact=rc&dur=426&oei=h9tsTebwLc3irAeW1Kz7Bg&page=1&ndsp=33&ved=1t:429,r:0,s:0&tx=57&ty=98"]; 
url = [webView.request URL];  
NSLog(@"urlrecieved .............................. %@", url); 
NSLog(@"urlrecieved 1 ............................. %@", url1); 
NSLog(@"urlrecieved 2.............................. %@", url2); 

if([url isEqualToString:url1]) 
{ 
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"warning" message:@"select an image" delegate:nil cancelButtonTitle:@"ok" otherButtonTitles:nil]; 
    [alert show]; 
    [alert release]; 
} 
else if([url isEqualToString:url2]) 
{ 
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"warning" message:@"select an image" delegate:nil cancelButtonTitle:@"ok" otherButtonTitles:nil]; 
    [alert show]; 
    [alert release]; 
} 
else 
{  
NSLog(@"Downloading..."); 
NSLog(@"url recieved: %@", url); 
UIImage *image = [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:url]]; 
NSLog(@"%f,%f",image.size.width,image.size.height); 
NSString *docDir = @"/Users/gauravmurghai/Desktop"; 
// If you go to the folder below, you will find those pictures 
    NSLog(@"%@",docDir); 
    NSLog(@"saving png"); 
// NSString *pngFilePath = [NSString stringWithFormat:@"%@/neetu%d.png",docDir , r]; 
//  r++; 

    NSString *pngFilePath = [NSString stringWithFormat:@"%@/flower.png",docDir]; 
    NSData *data1 = [NSData dataWithData:UIImagePNGRepresentation(image)]; 
    [data1 writeToFile:pngFilePath atomically:YES]; 
    [image release]; 
} 

}

Answer 1

它实际上需要一点点工作，以绝对确保两个URL是相同的。看看这篇博客文章，解释更多。

NSURL Equality

Answer 2

基类iOS的对象分层结构，NSObject的的，具有由子类ovverrided提供平等检查方法的isEqual。 NSUrl将提供它自己的实现，所以你不必担心转换为NSString来执行比较。

NSURL *url1 = [NSURL URLWithString:@"http://www.google.com"]; 
NSURL *url2 = [NSURL URLWithString:@"http://www.google.com"]; 
if ([url1 isEqual:url2]) { 
......