如何将类型为id的对象转换或设置为其他类型，例如UIImageView或UIView

Question

在下面的代码中，我遍历条目，它们可能是UIView或UIImageView类型。我想检查uiComponent是否为上述类型之一，然后我要根据以下代码继续使用该uiComponent是UIView还是UIImageView？

我死掉了下面的代码，但是我不能使用指针对象

uiComponent

键入后？

[请让我知道如何在UIView或UIImageView类中键入uiComponent对象，然后继续使用它进行编程

代码

 for (id uiComponent in uiviews) {
            UIView *uiView;
            UIImage *uiImageView;

         if ([AQSViewHelper isEntryOfTypeUIView:uiComponent]) {
                uiComponent = (UIView *)uiComponent;
         }
            if ([AQSViewHelper isEntryOfTypeUIImageView:uiComponent]) {
            uiComponent = (UIImageView *)uiComponent;
        }

         if (![uiComponent isHidden]) {
            …
    ..
    …
            }

Answer 1

根据类型设置本地对象，如果不是nil，则使用它：

for (id uiComponent in uiviews) {
    UIView *uiView;
    UIImageView *uiImageView;

    if ([AQSViewHelper isEntryOfTypeUIView:uiComponent]) {
        uiView = (UIView *)uiComponent;
    }
    if ([AQSViewHelper isEntryOfTypeUIImageView:uiComponent]) {
        uiImageView = (UIImageView *)uiComponent;
    }

    if (uiView) {
        // do what you want because it's a UIView
        if ([uiView isHidden]) {
            // ...
        }
        // etc ...
    }
    if (uiImageView) {
        // do what you want because it's a UIView
        if ([uiImageView isHidden]) {
            // ...
        }
        // etc ...
    }
}

或者，由于您已经在if块中，因此可以在此处进行：

for (id uiComponent in uiviews) {
    if ([AQSViewHelper isEntryOfTypeUIView:uiComponent]) {
        // do what you want because it's a UIView
        UIView *uiView = (UIView *)uiComponent;
        if ([uiView isHidden]) {
            // ...
        }
        // etc ...
    }
    if ([AQSViewHelper isEntryOfTypeUIImageView:uiComponent]) {
        // do what you want because it's a UIImageView
        UIImageView *uiImageView = (UIImageView *)uiComponent;
        if ([uiImageView isHidden]) {
            // ...
        }
        // etc ...
    }
}