blocks|key|426938|text|我认为，唯一的替代方法是创建一个名为onResume的函数，它将设置所有的大小和位置。无论如何，通过权重，你只能设置大小，但不能设置填充(因此布局变得更加复杂)，不能设置文本大小(不可能以某种方式补偿这一点)，更不用说行数这样的东西了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|426939|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

I think, the only alternative is to make a function that would be called onResume and will set all sizes and positions. Anyway, by weight you can set only sizes but no padding's (so layouts become even more complicated), no textSize's (impossible to compensate this somehow), let alone such things as number of lines.

blocks|key|641487|text|嵌套权重不好的主要原因是，当一个布局有一个权重的子级时，它必须测量两次(我想这在lint-warning中提到过)。这意味着，也包含加权布局的加权布局必须测量四次，并且您添加的每个权重“层”都会以2的幂增加度量。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|641488|在ICS+(API14级)中添加了GridLayout，它可以为许多以前需要权重的布局提供简单和“扁平”的解决方案。如果你是为早期版本的Android进行开发，你会有一个稍微困难的时间来移除权重，但是使用RelativeLayout并将尽可能多的布局展平到驾驶室中通常会移除很多嵌套的权重。|offset|length|style|CODE|641489|entityMap|0|LINK|mutability|MUTABLE|url|http://developer.android.com/reference/android/widget/GridLayout.html^0|0|H|A|2U|E|H|A|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Q|8|@$D|R|E|S|F|G]|$D|T|E|U|F|G]]|9|@$D|V|E|W|1|X]]|A|$]]|$1|H|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|I|$J|$5|K|L|M|A|$N|O]]]]

The main reason why nested weights are bad is that when a layout has children with a weight, it has to be measured twice (I think this is mentioned in the lint-warning). This means that a weighted layout that also contains a weighted layout has to measured four times, and each 'layer' of weights you add increase the measures with a power of two. 

In ICS (API level 14) the <a href="http://developer.android.com/reference/android/widget/GridLayout.html"><code>GridLayout</code></a> was added, which allows simple and 'flat' solutions for many layouts which previously required weights. If you are developing for earlier versions of Android you will have a slightly harder time removing weights, but using a <code>RelativeLayout</code> and flattening as much as possible of your layout into that cab usually remove a lot of the nested weights.

blocks|key|427097|text|我认为(我可能会为此感到愤怒)，但我再次认为我的手机有一个四核处理器，可以与大多数人的家用PC相媲美(如果不是完全摧毁的话)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|427098|我也认为这种硬件功能是手机的未来。|427099|所以我得出了一个结论，只要你不被嵌套迷住了(在MHO中，布局不应该超过4层深，如果是这样，你可能做错了)，你的手机可以不太关心是否有重量。|427100|有很多事情你可以做，这些事情会对性能产生更深远的影响，然后担心你的处理器会做一些额外的数学运算。|427101|(请注意，我是有点幽默的，所以不要太认真地对待这篇文章中的任何东西，除了你应该首先优化其他东西的想法，担心2-3级的深度体重对你的健康没有帮助)|427102|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|N|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|O|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|P|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|K|$]]

I think (and I will probably be flamed for this), but again I think my phone has a quad core processor to rival (if not utterly destroy) most peoples home PC's.

I also think this kind of hardware capability is the future of phones.

So I come to a conclusion, that as long as you are not getting carried away with nesting (in MHO a layout should never be more then 4 levels deep, and if it is you are probably doing it wrong), your phone could care less about having weights.

There are many things you can do that will have a much more far reaching effect on performance, then worrying about your processor doing some extra math.

(please note that I am being slightly humorous, and so not to take anything too seriously from this post, other then the idea that there are other things you should optimize first, and that worrying about a 2-3 level deep weight is not helping your health)

blocks|key|427155|text|有一个简单的解决方案来避免带有权重的嵌套LinearLayouts+-只需使用带有weighSum的Tablelayout和带有weightSum的嵌套LinearLayout+-+Tablelayout具有与LinearLayout相同的属性(orientation，weightSum，layout_weight等)。并且不显示消息-“嵌套的权重对性能不好”|type|unstyled|depth|inlineStyleRanges|entityRanges|data|427156|示例：|427157|+<TableLayout
++++++++android:layout_width="match_parent"
++++++++android:layout_height="match_parent"
++++++++android:orientation="vertical"
++++++++android:weightSum="1">

++++++++<ImageView
++++++++++++android:layout_width="match_parent"
++++++++++++android:layout_height="0dp"
++++++++++++android:layout_weight="0.8"/>


++++++++<LinearLayout
++++++++++++android:layout_width="match_parent"
++++++++++++android:layout_height="0dp"
++++++++++++android:layout_weight="0.2"
++++++++++++android:orientation="horizontal"
++++++++++++android:weightSum="1">


++++++++++++<ImageView
++++++++++++++++android:layout_height="match_parent"
++++++++++++++++android:layout_width="0dp"
++++++++++++++++android:layout_weight="0.4"/>

++++++++++++<TextView
++++++++++++++++android:layout_height="match_parent"
++++++++++++++++android:layout_width="0dp"
++++++++++++++++android:layout_weight="0.6"/>


++++++++++++</LinearLayout>

++++</TableLayout>|code-block|syntax|javascript|427158|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

There is an easy solution to avoid nested LinearLayouts with weights - just use Tablelayout with weighSum and nested LinearLayout with weightSum - Tablelayout has the same attributes as LinearLayout(orientation, weightSum, layout_weight, etc.) and doesn't show message - "nested weights have bad for performance" 

Example:

<pre><code> &lt;TableLayout
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical"
 android:weightSum="1"&gt;

 &lt;ImageView
 android:layout_width="match_parent"
 android:layout_height="0dp"
 android:layout_weight="0.8"/&gt;


 &lt;LinearLayout
 android:layout_width="match_parent"
 android:layout_height="0dp"
 android:layout_weight="0.2"
 android:orientation="horizontal"
 android:weightSum="1"&gt;


 &lt;ImageView
 android:layout_height="match_parent"
 android:layout_width="0dp"
 android:layout_weight="0.4"/&gt;

 &lt;TextView
 android:layout_height="match_parent"
 android:layout_width="0dp"
 android:layout_weight="0.6"/&gt;


 &lt;/LinearLayout&gt;

 &lt;/TableLayout&gt;
</code></pre>

I have written a couple layout files where I used the <code>layout_weight</code> attribute to create a ratio between different views.

At some point, I start getting lint warnings about nested weights. 

So, I wonder why are nested weights bad for performance, and if there is a more efficient way to create a constant ratio between view dimensions that could be used for different screen sizes and that doesn't need to specify a lot of dimension dpi values throught several layout files (for different screen sizes, I mean).

Thank you!

Why are nested weights bad for performance? Alternatives?

Android

我已经编写了几个布局文件，其中我使用layout_weight属性来创建不同视图之间的比率。在某些时候，我开始收到关于嵌套权重的lint警告。所以，我想知道为什么嵌套的权重对性能不好，是否有一种更有效的方法来创建视图尺寸之间的恒定比率，可以用于不同的屏幕尺寸，并且不需要通过几个布局文件指定大量的尺寸dpi值(我的意思是...

问为什么嵌套的权重对性能不好？替代方案？
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