android 关于如何获取控件矩阵 getHitRect

From: http://blog.csdn.net/tiantianshangcha/article/details/8109744

getHitRect作为获取控件所在的矩阵范围函数，简直就像个神器。当然他也有不给力的情况，我们平常调用时候如果是在控件的监听器里调用就没事，但是如果主动的在onCreate 或者 onResume中，拿到的矩阵坐标全是0.

解决如下：

As the hit rect is in the parent coordinate space, the parent first needs to layout its children which it hasn't done yet during onCreate(). Take a look at the solution here for an example of running in post(). If you have a custom view, getHitRect() within onDraw() will give you the correct dimensions too.

大概意思就是getHitRect方法不能直接在onCreate中调用 ，原因是该控件还未在这个界面框架中得以测量布局，不知道到底是多少，所以我们要寻找一个时机去做这件事，两个方法：

方法1   运用该控件执行post    （就把下面的那个parent当成你要获取getHitRect的方法）

I asked a friend at Google and they were able to help me figure out how to use TouchDelegate. Here's what we came up with:

<code style="margin:0px; padding:0px; border:0px; vertical-align:baseline; font-family:Consolas,Menlo,Monaco,'Lucida Console','Liberation Mono','DejaVu Sans Mono','Bitstream Vera Sans Mono','Courier New',monospace,serif"><span class="kwd" style="color:#008b;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">final</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="typ" style="color:#2b91af;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">View</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> parent </span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">=</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">(</span><span class="typ" style="color:#2b91af;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">View</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">)</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="kwd" style="color:#008b;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">delegate</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">.</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">getParent</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">();</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">parent</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">.</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">post</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">(</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="kwd" style="color:#008b;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">new</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="typ" style="color:#2b91af;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">Runnable</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">()</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">{</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">    </span><span class="com" style="color:gray;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">// Post in the parent's message queue to make sure the parent</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">    </span><span class="com" style="color:gray;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">// lays out its children before we call getHitRect()</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">    </span><span class="kwd" style="color:#008b;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">public</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="kwd" style="color:#008b;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">void</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> run</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">()</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">{</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">        </span><span class="kwd" style="color:#008b;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">final</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="typ" style="color:#2b91af;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">Rect</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> r </span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">=</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="kwd" style="color:#008b;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">new</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="typ" style="color:#2b91af;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">Rect</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">();</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">        </span><span class="kwd" style="color:#008b;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">delegate</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">.</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">getHitRect</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">(</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">r</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">);</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">        r</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">.</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">top </span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">-=</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="lit" style="color:#8000;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">4</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">;</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">        r</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">.</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">bottom </span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">+=</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="lit" style="color:#8000;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">4</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">;</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">        parent</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">.</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">setTouchDelegate</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">(</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="kwd" style="color:#008b;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">new</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="typ" style="color:#2b91af;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">TouchDelegate</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">(</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> r </span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">,</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"> </span><span class="kwd" style="color:#008b;margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent;">delegate</span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">));</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">    </span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">}</span><span class="pln" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent"></span><span class="pun" style="margin:0px; padding:0px; border:0px; vertical-align:baseline; background-color:transparent">});</span></code>

方法2  自定义该控件 覆写onDraw  调用getHitRect.

学弟，学长只能帮到你这里了！