如果语句不适用于indexpath

Question

如果我对if语句做错什么，我会很痛苦。

我正在对两个indexPath进行配对，如果旧索引与当前选择的索引不相等，我想做其他一些明智的做法，如往常一样。

但是即使我的if语句总是被访问，即使它们是！= ..我做错了..我知道您可以检查IsEqual：这里是否有！=这样的内容？

这是我的代码和输出

NSLog(@"%@", modelIndexPath);
            NSLog(@"%@", oldCheckedIndexPath);
            NSLog(@"%@", indexPath);
            if (modelIndexPath != indexPath) {
                NSLog(@"Not Equal");
                NSLog(@" ");
            }

2012-01-19 16:09:06.521 Code[9907:207] (null)
2012-01-19 16:09:06.522 Code[9907:207] (null)
2012-01-19 16:09:06.523 Code[9907:207] <NSIndexPath 0xc2993e0> 2 indexes [9, 0]
2012-01-19 16:09:06.524 Code[9907:207] Not Equal
2012-01-19 16:09:06.525 Code[9907:207]  
2012-01-19 16:09:17.921 Code[9907:207] <NSIndexPath 0xc2993e0> 2 indexes [9, 0]
2012-01-19 16:09:17.922 Code[9907:207] <NSIndexPath 0xc2993e0> 2 indexes [9, 0]
2012-01-19 16:09:17.923 Code[9907:207] <NSIndexPath 0xc5b0c50> 2 indexes [9, 0]
2012-01-19 16:09:17.924 Code[9907:207] Not Equal
2012-01-19 16:09:17.925 Code[9907:207]  
2012-01-19 16:09:29.489 Code[9907:207] <NSIndexPath 0xc5b0c50> 2 indexes [9, 0]
2012-01-19 16:09:29.490 Code[9907:207] <NSIndexPath 0xc5b0c50> 2 indexes [9, 0]
2012-01-19 16:09:29.491 Code[9907:207] <NSIndexPath 0xc7886c0> 2 indexes [9, 2]
2012-01-19 16:09:29.491 Code[9907:207] Not Equal
2012-01-19 16:09:29.492 Code[9907:207]  
2012-01-19 16:09:34.945 Code[9907:207] <NSIndexPath 0xc7886c0> 2 indexes [9, 2]
2012-01-19 16:09:34.946 Code[9907:207] <NSIndexPath 0xc7886c0> 2 indexes [9, 2]
2012-01-19 16:09:34.946 Code[9907:207] <NSIndexPath 0xc89e780> 2 indexes [9, 2]
2012-01-19 16:09:34.947 Code[9907:207] Not Equal
2012-01-19 16:09:34.948 Code[9907:207]  
2012-01-19 16:09:37.601 Code[9907:207] <NSIndexPath 0xc89e780> 2 indexes [9, 2]
2012-01-19 16:09:37.602 Code[9907:207] <NSIndexPath 0xc89e780> 2 indexes [9, 2]
2012-01-19 16:09:37.602 Code[9907:207] <NSIndexPath 0xc94e480> 2 indexes [9, 1]
2012-01-19 16:09:37.603 Code[9907:207] Not Equal
2012-01-19 16:09:37.604 Code[9907:207] 

UPDate：

这是你们的帮助下的当前状况

NSLog(@"%@", modelIndexPath);
            NSLog(@"%@", oldCheckedIndexPath);
            NSLog(@"%@", indexPath);

            if ( [modelIndexPath isEqual:indexPath] ) NSLog(@"hurray!");
            if ( ![modelIndexPath isEqual:indexPath] ) NSLog(@"bummer");
            NSLog(@" ");



2012-01-19 16:41:54.853 Code[11071:207] (null)
2012-01-19 16:41:54.854 Code[11071:207] (null)
2012-01-19 16:41:54.855 Code[11071:207] <NSIndexPath 0xc21f9a0> 2 indexes [9, 0]
2012-01-19 16:41:54.856 Code[11071:207] bummer
2012-01-19 16:41:54.856 Code[11071:207]  
2012-01-19 16:41:59.637 Code[11071:207] <NSIndexPath 0xc21f9a0> 2 indexes [9, 0]
2012-01-19 16:41:59.637 Code[11071:207] <NSIndexPath 0xc21f9a0> 2 indexes [9, 0]
2012-01-19 16:41:59.638 Code[11071:207] <NSIndexPath 0x6a73e10> 2 indexes [9, 0]
2012-01-19 16:41:59.639 Code[11071:207] hurray!
2012-01-19 16:41:59.639 Code[11071:207]  
2012-01-19 16:42:05.492 Code[11071:207] <NSIndexPath 0x6a73e10> 2 indexes [9, 0]
2012-01-19 16:42:05.493 Code[11071:207] <NSIndexPath 0x6a73e10> 2 indexes [9, 0]
2012-01-19 16:42:05.494 Code[11071:207] <NSIndexPath 0x6aae9d0> 2 indexes [9, 0]
2012-01-19 16:42:05.494 Code[11071:207] hurray!
2012-01-19 16:42:05.495 Code[11071:207]  
2012-01-19 16:42:10.901 Code[11071:207] <NSIndexPath 0x6aae9d0> 2 indexes [9, 0]
2012-01-19 16:42:10.902 Code[11071:207] <NSIndexPath 0x6aae9d0> 2 indexes [9, 0]
2012-01-19 16:42:10.902 Code[11071:207] <NSIndexPath 0xc625470> 2 indexes [9, 2]
2012-01-19 16:42:10.903 Code[11071:207] bummer

Answer 1

NSIndexPath是对象，使用进行比较

if (![modelIndexPath isEqual:indexPath])

编辑：也许发布更多代码，上面的代码应该可以用，或者您也可以用，（仍然取决于您的需要）

int modelRow = [modelIndexPath row];
int indexRow = [indexPath row];

if (modelRow != indexRow)
{
    // Do something here
}

请注意，这只会根据您的需要起作用！

Answer 2

这些NSIndexPath事物是对象，您正在比较它们的内存地址。 换句话说， modelIndexPath和indexPath都是指针 。 （谷歌是你的朋友）

要比较这些对象，请使用：

if ( [modelIndexPath isEqual:indexPath] ) NSLog(@"hurray!");

要么

if ( ![modelIndexPath isEqual:indexPath] ) NSLog(@"bummer");

测试不平等。

Answer 3

您正在比较实例地址。 使用if (![modelIndexPath isEqual:indexPath]) { //...

Answer 4

使用isEqual:而不是==

==表示两个参考点是否指向同一对象

isEqual:表示对象相等

if ([modelIndexPath isEqual: indexPath]) {
                NSLog(@"Not Equal");
                NSLog(@" ");
            }