神秘的內存泄漏 - NSString自動釋放問題

Question

即使我在緊密循環中使用NSAutoreleasePool，下面方法中的以下行導致我獲取內存警告並最終崩潰我的應用程序（通過注釋掉該行，問題消失）。 任何人都知道為什么會這樣？

filepath = [docpath stringByAppendingPathComponent:file];

-(void)fileCleanup
{
    NSString *documentspath = [AppSession documentsDirectory];
    NSString *docpath = [documentspath stringByAppendingPathComponent:@"docs"];
    NSFileManager *filemanager = [NSFileManager defaultManager];
    NSArray *files = [filemanager subpathsOfDirectoryAtPath:docpath error:NULL];
    NSLog(@"fileCleanup");
    if(files != nil && [files count] > 0)
    {
        BOOL deletefile;
        NSString *filepath;
        NSAutoreleasePool *readPool;
        NSString *testfile;
        NSString *file;

        for(file in files) 
        {
            deletefile = YES;

            for (testfile in allFiles) {
                readPool = [[NSAutoreleasePool alloc] init];

                //line below is causing memory leak!
                filepath = [docpath stringByAppendingPathComponent:file];
                //if([filepath isEqualToString:testfile])
                //{
                   // deletefile = NO;
                   // break;
                //} 
                [readPool drain];
            }

            if(deletefile)
            {
                [self logText:[@"\nD: " stringByAppendingString:[@"docs/" stringByAppendingPathComponent:file]]];
                [filemanager removeItemAtPath:[docpath stringByAppendingPathComponent:file] error:NULL];
            }
        }
    }

Answer 1

我用php in_array（）函數的Objective C等效替換了內部的“for”循環，內存問題消失了！

    NSUInteger matchint = [allFiles indexOfObject:[docpath stringByAppendingPathComponent:file]];
    if(matchint != NSNotFound)
        deletefile = NO;

Answer 2

break語句讓你退出你的內部for循環而不在NSAutoreleasePool上調用-drain。