Question

以下示例程序：虽然相同的url它找不到url，但程序无法正常工作。

NSDirectoryEnumerator *directoryEnumerator = [[NSFileManager defaultManager] enumeratorAtPath:kDocdir];
for (NSString *pathi in directoryEnumerator)
{
    NSLog(@"fileManager_url = %@",[self Doc_Del:pathi]);
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"url == %@",[self Doc_Del:pathi]];
    [fetchRequest setPredicate:predicate];
    NSArray *fetchedObjects = [context executeFetchRequest:fetchRequest error:nil];


    Artist *url_Databse =  [self.fetchedResultsController  objectAtIndexPath:self.indexPath_k];
    NSLog(@"Database_url = %@",url_Databse.url);


    if ([fetchedObjects count] > 0) {
        NSLog(@"foundurl = %@",((Artist *)[fetchedObjects objectAtIndex:0]).url);
    }else{
        NSLog(@"url not found");
    }
}

输出：

2013-04-25 15:37:43.256 Player[36436:907] fileManager_url  = /alizée -öş mèxico - final j'en
2013-04-25 15:37:43.272 Player[36436:907] Database_url     = /alizée -öş mèxico - final j'en
2013-04-25 15:37:44.107 Player[36436:907] url not found

当url中的特殊字符时，

无法正常工作。为什么会这样？谢谢......

Answer 1

HFS文件系统使用“decomposite characters”，例如文件名中的é存储为两个字符e + ´（U + 0301，COMBINING ACUTE ACCENT）。使用precomposedStringWithCanonicalMapping从目录枚举中规范化文件名应该会有所帮助。

IOS NSPredicate不工作

1 个答案: