Question

我有一个名为svCreateTask的scrollView。在这个scrollView中，我按下了按钮UITextField，UITextView，UIButtons静态和UIView编程。现在我想在按下按钮时删除选定的UIView。和视图从scrollView中移除，其标记与Button标记相同。

if语句检查每个时间为TRUE，因此其标签与我的按钮标签相同的其他子视图也会从scrollView中删除。我只想删除UIView。

我在这里发布我的代码：

 NSLog(@"Enter in removeNotification method.");

    UIButton *btn = (UIButton *)sender;
    NSLog(@"btn Tag = %d",[btn tag]);

    NSArray *viewsToRemove = [svCreateTask subviews];

    for (int i=0; i<viewsToRemove.count; i++)
    {
        NSLog(@"Class == %@",[[viewsToRemove objectAtIndex:i] class]);
        if ([[viewsToRemove objectAtIndex:i]isKindOfClass:[UIView class]])
        {
            NSLog(@"In Class Check...");
            UIView *v =[viewsToRemove objectAtIndex:i];
            if (v.tag == btn.tag)
            {
                [v removeFromSuperview];
            }
        }

    }

我的NSLog是。

2014-05-13 14:49:42.769 TOPDesign[379:11303] Enter in removeNotification method.
2014-05-13 14:49:42.770 TOPDesign[379:11303] btn Tag = 1
2014-05-13 14:49:42.771 TOPDesign[379:11303] Class == UILabel
2014-05-13 14:49:42.772 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.773 TOPDesign[379:11303] Class == UITextView
2014-05-13 14:49:42.773 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.774 TOPDesign[379:11303] Class == UITextField
2014-05-13 14:49:42.775 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.775 TOPDesign[379:11303] Class == UIButton
2014-05-13 14:49:42.776 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.777 TOPDesign[379:11303] Class == UIButton
2014-05-13 14:49:42.777 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.778 TOPDesign[379:11303] Class == UIButton
2014-05-13 14:49:42.779 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.780 TOPDesign[379:11303] Class == UIButton
2014-05-13 14:49:42.780 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.781 TOPDesign[379:11303] Class == UIButton
2014-05-13 14:49:42.782 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.782 TOPDesign[379:11303] Class == UIButton
2014-05-13 14:49:42.783 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.783 TOPDesign[379:11303] Class == UILabel
2014-05-13 14:49:42.784 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.784 TOPDesign[379:11303] Class == UILabel
2014-05-13 14:49:42.785 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.786 TOPDesign[379:11303] Class == UIImageView
2014-05-13 14:49:42.786 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.787 TOPDesign[379:11303] Class == UIImageView
2014-05-13 14:49:42.787 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.788 TOPDesign[379:11303] Class == UIImageView
2014-05-13 14:49:42.788 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.789 TOPDesign[379:11303] Class == UIImageView
2014-05-13 14:49:42.789 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.790 TOPDesign[379:11303] Class == UIImageView
2014-05-13 14:49:42.799 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.801 TOPDesign[379:11303] Class == UIView
2014-05-13 14:49:42.801 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.802 TOPDesign[379:11303] Class == UIView
2014-05-13 14:49:42.802 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.803 TOPDesign[379:11303] Class == UIImageView
2014-05-13 14:49:42.803 TOPDesign[379:11303] In Class Check...
2014-05-13 14:49:42.804 TOPDesign[379:11303] Class == UIView
2014-05-13 14:49:42.805 TOPDesign[379:11303] In Class Check...

我的屏幕结构是。

UIView(main view) > ScrollView > TextField,TextView,Label, Buttons, UIView Etc.

我想获得UIView哪个是我scrollView的子视图。

Answer 1

对于任何派生类，

isKindOfClass都返回true。因为所有与用户界面相关的类都派生自UIView，所以此方法对您案例中的所有对象都返回true。

如果您只想测试UIView类：

，请使用此类代码

if ([obj class] == [UIView class]) {
}

此代码仅检查UIView类型的对象。

Answer 2

您想要的是使用方法isMemberOfClass:。（查看Apple文档中的isMemberOfClass方法）

isMemberOfClass: - 返回一个布尔值，指示接收者是否是给定类的实例。（所需的）

然后（查看Apple文档中的isKindOfClass:方法）

isKindOfClass: - 返回一个布尔值，指示接收者是给定类的实例还是从该类继承的任何类的实例。（所需的）

所以基本上当你进行isKindOfClass:检查时，它会为TRUE的任何子类返回UIView，因此这包括UIButton，UILabel等

所以将if ([[viewsToRemove objectAtIndex:i]isKindOfClass:[UIView class]])更改为if ([[viewsToRemove objectAtIndex:i] isMemberOfClass:[UIView class]])

UILabel的继承示例如UILabel＆gt;＆gt; UIView＆gt;＆gt; UIResponder＆gt;＆gt; NSObject。因此，当您执行isKindOfClass:[UIView class]时，TRUE会返回UILabel，因为您可以看到UILabel是UIView的子类，但如果我们isMemberOfClass:[UIView class] UILabel我们忽略任何子类化对象，例如FALSE，因此这将为UILabel返回TRUE，但仍会为UIView返回UIVeiws。

另一种解决方案是在创建viewWithTag:时为他们提供标记，因此在删除标记时，您只需使用{{1}}获取要删除的特定视图即可。

Answer 3

你遇到的问题是视图层次结构中的每个东西都是以UIView作为它的基类，所以你每次都得到True。处理此问题的一种可能解决方案如下：

给你的UIView提供一些特殊标签，好像通常你给标签为3，然后你可以将它的标签乘以1000，现在得到True，你可以计算出如果UIView包含三个0，然后删除它保留它:)）

Answer 4

这是另一种方式。

UIView *v;
for (int i=0; i<viewsToRemove.count; i++)
{
    v = [viewsToRemove objectAtIndex:i]
    if ([NSStringFromClass([v class]) isEqualToString:@"UIView"])
    {
        //Remove view
    }
}

在其他答案中，我认为使用大力水手提到的isMemberOfClass是正确的方法。

isKindOfClass每次都返回TRUE？

4 个答案: