Question

我正在使用TouchXML来解析XML。虽然我在“配置文件”模式下运行相同。我能够看到内存泄漏。我该如何解决这个问题？

-(NSMutableArray *) grabXML:(NSData *)xmlData andQuery:(NSString *)query {  
    NSMutableArray *blogEntries = [[[NSMutableArray alloc] init] autorelease];  
    CXMLDocument *rssParser = [[[CXMLDocument alloc] initWithData:xmlData options:0 error:nil] autorelease];
    NSArray *resultNodes = [rssParser nodesForXPath:query error:nil];
    for (CXMLElement *resultElement in resultNodes) {
        NSMutableDictionary *blogItem = [[NSMutableDictionary alloc] init];
        int counter;
        for(counter = 0; counter < [resultElement childCount]; counter++) {
            [blogItem setObject:[[resultElement childAtIndex:counter] stringValue] forKey:[[resultElement childAtIndex:counter] name]];
        }
        for( int i = 0; i < [[resultElement attributes] count]; i++) {
            CXMLNode *node = [[resultElement attributes] objectAtIndex:i];
            [blogItem setObject:[[resultElement attributeForName:[node name]] stringValue] forKey:[node name]];
        }
        [blogEntries addObject:[blogItem copy]];
        [blogItem release];
    }
    return [blogEntries copy];
}

我以下面提到的格式调用上述方法。

NSMutableArray *arr = [[self grabXML:responseData andQuery:@"//wsCheneliereResult"] autorelease];

Answer 1

[blogEntries addObject:[blogItem copy]];

这是您的错误：您不需要复制blogItem，addObject:实际上会retain其参数，以便您可以在之后安全地致电[blogItem release];。

你很可能也不应该return [blogEntries copy]，只返回blogEntries：这是常见的编程习惯，其名称不包含'copy'或'create'的方法会返回自动释放的值，例如因为当你完成它们时你不需要释放它们。

总结一下，我会选择：

-(NSMutableArray *) grabXML:(NSData *)xmlData andQuery:(NSString *)query {  
    NSMutableArray *blogEntries = [[[NSMutableArray alloc] init] autorelease];  
    CXMLDocument *rssParser = [[[CXMLDocument alloc] initWithData:xmlData options:0 error:nil] autorelease];
    NSArray *resultNodes = [rssParser nodesForXPath:query error:nil];
    for (CXMLElement *resultElement in resultNodes) {
        NSMutableDictionary *blogItem = [[NSMutableDictionary alloc] init];
        int counter;
        for(counter = 0; counter < [resultElement childCount]; counter++) {
            [blogItem setObject:[[resultElement childAtIndex:counter] stringValue] forKey:[[resultElement childAtIndex:counter] name]];
        }
        for( int i = 0; i < [[resultElement attributes] count]; i++) {
            CXMLNode *node = [[resultElement attributes] objectAtIndex:i];
            [blogItem setObject:[[resultElement attributeForName:[node name]] stringValue] forKey:[node name]];
        }
        [blogEntries addObject:blogItem];
        [blogItem release];
    }
    return blogEntries;
}

和

NSMutableArray *arr = [self grabXML:responseData andQuery:@"//wsCheneliereResult"];

使用TouchXML解析XML时内存泄漏

1 个答案: