如何在objective-c中查找类的多个实例

Question

我有一个UIView类，它有许多UITextField子类的子视图。有没有办法迭代一个类列表来找到UITextField子类

Answer 1

是的！

假设您将代码放在UIView子类中，您可以获取一组子视图......

NSArray *sbviews = [self subviews];
NSMutableArray *textFields; //placeholder for your UITextField subclassed objects.

//enumerate through the subview collection and only add objects to the textFields array that are UITextField objects.
for (id anObject in sbviews) {
    if([anObject isKindOfClass: [UITextField class]]){
        [textField addObject: anObject];
    }
}

textField数组现在将包含UITextField类的所有对象...

Answer 2

您的UIView类有一个子视图数组，列出了您添加到它的所有子视图。您可以通过数组进行迭代，并查找UITextField对象的实例（而不是类）。

for (UITextField* textField in [someView subviews]) {
    if ([textField isKindOfClass:[UITextField class]]) {
        // found one, textField really is a UITextField
    }
}