Question

想象一下，你有两条路。

http://myserver.com/path1/path2 + /path1/path2/cache/image1.jpg = http://myserver.com/path1/path2/cache/image1.jpg

两个路径字符串都可以有更多或更少的路径组件。

所以我要问的是如何在字符串中找到相等的部分，然后从其中一个字符串中删除该部分？

Answer 1

您不知道“相等”部分是否真的相同。例如，路径如... / part1 / part1 / part1 /...

并不罕见

对于处理路径的机制，NSString有一些不错的方法 - lastPathComponent，stringByAppendindPathComponent，pathComponents，pathWithComponents等。

Answer 2

这个怎么样：

- (NSString *)mergeStringsPrefix:(NSString *)prefix suffix:(NSString *)suffix
{
    NSString *string = [NSString stringWithFormat:@"%@", prefix];

    NSArray *prefixComponents = [prefix pathComponents];
    NSArray *suffixComponents = [suffix pathComponents];

    if ([prefixComponents count] == 0) return [string retain]; 
    int rootIndex = [suffixComponents indexOfObject:@"/"];
    int index = 1;
    if (rootIndex == NSNotFound || rootIndex != 0) index = 0;

    int startIndex = [prefixComponents indexOfObject:[suffixComponents objectAtIndex:index]];
    if (startIndex == NSNotFound) return nil;

    if ([suffixComponents count] - index < [prefixComponents count] - startIndex) return nil;

    // fing length and check merge compatability
    BOOL equalParts = YES;
    for (int i=startIndex; i<[prefixComponents count] && equalParts; i++, index++)
    {
        NSString *el1 = [prefixComponents objectAtIndex:i];
        NSString *el2 = [suffixComponents objectAtIndex:index];

        if ([el1 compare:el2] != NSOrderedSame) equalParts = NO;
    }
    if (!equalParts) return nil;
    // merge
    for (int i=index; i<[suffixComponents count]; i++)
    {
        string = [string stringByAppendingFormat:@"/%@", [suffixComponents objectAtIndex:i]];
    }

    return [string retain];
}

Answer 3

这应该适合你：

NSString* path1 = @"http://myserver.com/path1/path2";
NSString* path2 = @"/path1/path2/cache/image1.jpg";

NSMutableArray* path1Components = [NSMutableArray arrayWithArray:[path1 componentsSeparatedByString:@"/"]];
NSMutableArray* path2Components = [NSMutableArray arrayWithArray:[path2 componentsSeparatedByString:@"/"]];
[path2Components removeObjectAtIndex:0];

if ([path1Components containsObject:[path2Components objectAtIndex:0]]) {

    NSUInteger objectIndex = [path1Components indexOfObject:[path2Components objectAtIndex:0]];

    [path1Components removeObjectsInRange:NSMakeRange(objectIndex, [path1Components count]-objectIndex)];

    [path1Components addObjectsFromArray:path2Components];

    NSString* mergedPath = [path1Components componentsJoinedByString:@"/"];

    NSLog(@"%@",mergedPath);

}

如何在xcode中合并路径（NSString）？

3 个答案: