问题描述
如果我宣布的LinearLayout LinearLayout中看看 linearLayout.getLayoutParams（），它给了我 ViewGroup.LayoutParams ，不是 LinearLayout.LayoutParams 。
If I declare LinearLayout linearLayout and look at linearLayout.getLayoutParams(), it gives me ViewGroup.LayoutParams, not LinearLayout.LayoutParams.
所以我必须使用的重复（因此坏）作风建设：
So I have to use the repeating (and thus bad) style construction of:
int lm = ((LinearLayout.LayoutParams) linearLayout.getLayoutParams()).leftMargin?
难道我真的要使用它，如果我想达到的利润，例如？
Do I really have to use it, if I want to reach margins, for example?
这是我的Android或Java或误解两者还是其他什么东西？
Is it my misunderstanding of Android or Java, or both or something else?
推荐答案
我觉得你对'的LayoutParams的理解不正确。视图的（或布局的）的LayoutParams 必须是'父视图的的LayoutParams的一个实例。
I think your understanding about 'LayoutParams' is incorrect. A view's (or layout's) LayoutParams must be an instance of 'the parent view's LayoutParams'.
例如，下面是在RelativeLayout的一个LinearLayout中。这LinearLayout中的的LayoutParams必须RelativeLayout.LayoutParams。这件事情使我们能够正确地设置属性，如centerInParent等。
For example, here's an LinearLayout in RelativeLayout. That LinearLayout's LayoutParams must be RelativeLayout.LayoutParams. This thing enables us to set the attributes properly, like 'centerInParent' and etc.
当你调用 getLayoutParams（），返回匹配于母公司的ViewGroup类型的LayoutParams的各种实例。因此，我们需要反复投下的视图的的LayoutParams类型时调用 getLayoutParams（）。
When you call getLayoutParams(), that returns various instance of LayoutParams that matches to parent ViewGroup type. As a result, we need to cast the type of a view's LayoutParams repeatedly when calling getLayoutParams().
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