Question

我正在疯狂地试图弄清楚如何实施tableView numberofRowsinSection，并希望我能得到一些提示或建议。我觉得我整个事情过于复杂。让我首先发布转换后的xml数据，现在是NSDictionary。

{
    "@body" = "";
    "@class_id" = "";
    "@title" = Discussions;
    "@type" = "Discussion Block";
},
{
    "@body" = "";
    "@class_id" = "";
    "@col" = 1;
    "@title" = YouTube;
    "@type" = "Youtube Block";
    item =     {
        "@body" = "http://www.youtube.com/watch?v=vDWhfsQHq1o&ob=av3e";
        "@title" = "Gavin DeGraw - Not Over You";
        "@type" = link;
    };
},
{
    "@body" = "";
    "@class_id" = "";
    "@title" = Calendar;
    "@type" = "Calendar Block";
},
{
    "@body" = "<p>  homework test</p> ";
    "@class_id" = "";
    "@title" = Homework;
    "@type" = "File Block";
    item =     (
                {
            "@body" = "https://MYDOMAIN.com/securelink;
            "@title" = "crashreport.rtf";
            "@type" = file;
        },
                {
            "@body" = "mydomain.com/securelink";
            "@title" = "Chem notes sep 26.docx";
            "@type" = file;
    }
);
},
{
    "@body" = "<p>  Link testing</p> ";
    "@class_id" = "";
    "@title" = Links;
    "@type" = "Link Block";
    item =     (
                {
            "@body" = "http://google.com";
            "@title" = Link1;
            "@type" = link;
        },
                {
            "@body" = "http://yahoo.com";
            "@title" = link2;
            "@type" = link;
        },
                {
            "@body" = "http://reddit.com";
            "@title" = link3;
            "@type" = link;
        }
    );
}
)

以上数据是回复。这样做的目的是让第一个标题键成为表格标题，将第二个“标题”键（在“项目”内）作为各自部分的行。在tableView TitleforHeaderinSection方法中，我只使用此代码

for (NSDictionary *roster in response) {
     [blockName addObject:[roster objectForKey@"@title"]];
 }
     return [blockName objectAtIndex:section];

numberofRowsinSection方法让事情变得棘手。这就是我试过的

for (NSDictionary *myDict in [[response objectAtIndex:section] valueForKeyPath:@"item"]) {
    NSArray *keys = [myDict allKeys];
    if ([keys containsObject:@"@title"]) {
        array3 = [[NSMutableArray alloc] init];
        [array3 addObject:[myDict objectForKey:@"@title"]];
    }
}
 return array3;

我得到的错误是myDict是NSString，并且不能在其上使用allKeys。我不确定为什么会发生这种情况，因为当我将其更改为objectAtIndex：1并记录allKeys方法时。我也很确定这不是找到每个部分所需行数的最佳方法，所以如果有更好的方法请分享。

为了澄清一下，在解析上述数据之后，这就是我在tableView中寻找的东西：

 Header (Discussions)
   -No rows under this header
 Header (YouTube)
   -Row (Gavin DeGraw - Not Over You)
 Header (Calendar)
   -No rows
 Header (Homework)
   -Row (crashreport)
   -Row (chem notes)
 Header (links)
   -Row (link1)
   -Row (link2)
   -Row (link3)

感谢您的帮助。我已经对NSDictionary和NSArray方法做了很多研究，但我不知道如何解决这个问题或者用其他方式编写代码。

Answer 1

问题在于：

for（[response objectAtIndex：section]中的NSDictionary * myDict valueForKeyPath：@＆＃34; item＆＃34;]）{

这适用于下面的字典，因为它遍历NSDray对象的NSArray。因此，当调用[myDict allKeys]时，您实际上是在NSDictionary上调用它。

{
    "@body" = "<p>  homework test</p> ";
    "@class_id" = "";
    "@title" = Homework;
    "@type" = "File Block";
    item =     (
                {
            "@body" = "https://MYDOMAIN.com/securelink;
            "@title" = "crashreport.rtf";
            "@type" = file;
        },
                {
            "@body" = "mydomain.com/securelink";
            "@title" = "Chem notes sep 26.docx";
            "@type" = file;
    }
);

但是对于下一个字典来说并不好，因为你循环遍历字典而不是数组，所以for..in循环是循环字典的键。然后，您在NSString上调用allKeys（也就是在字典中的键上）。

{
    "@body" = "";
    "@class_id" = "";
    "@col" = 1;
    "@title" = YouTube;
    "@type" = "Youtube Block";
    item =     {
        "@body" = "http://www.youtube.com/watch?v=vDWhfsQHq1o&ob=av3e";
        "@title" = "Gavin DeGraw - Not Over You";
        "@type" = link;
    };
},

你可以这样做：

id item = [[response objectAtIndex:section] valueForKeyPath:@"item"];
if(item) {
    if([item isKindOfClass:[NSDictionary class]]) {
        NSArray *keys = [(NSDictionary *)item allKeys];
    } else if([item isKindOfClass:[NSArray class]]) {
        for (NSDictionary *myDict in (NSArray *)item) {
            NSArray *keys = [myDict allKeys];
        }
    }
}
else {
  return 0;
}

Answer 2

假设存在“item”键，则相应的对象是项目的NSArray。

尝试：

NSArray *items = [[response objectAtIndex:section] valueForKey:@"item"];

if (items!=nil) {
    return [items count];
} else {
    return 0;
}

_NSCFString allKeys，无法识别的选择器。我以为这是一个NSDictionary？

2 个答案: