Android clipChildren用法

android:clipChildren先看官方介绍

Defines whether a child is limited to draw inside of its bounds or not. 

This is useful with animations that scale the size of the children to more than 100% for instance. 

In such a case, this property should be set to false to allow the children to draw outside of their bounds.

意思是说，通过设置clipChildren可以是子视图超出其layout范围绘画，默认是不允许的。

一般情况下不会使用到该属性，因为需要多嵌套一层甚至多层，在复杂的布局中会影响到layout的效率。

但是是动画方面却很有用途。看下图

clipChildren=true时，

clipChildren=false时，

layout.xml

[html] view plain copy <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
    android:layout_width="match_parent"  
    android:layout_height="match_parent"  
    android:clipChildren="false"  
    android:gravity="center">  
  
    <LinearLayout  
        android:layout_width="100dp"  
        android:layout_height="100dp"  
        android:background="@android:color/darker_gray"  
        android:gravity="center">  
  
        <TextView  
            android:layout_width="wrap_content"  
            android:layout_height="wrap_content"  
            android:background="@android:color/holo_red_dark"  
            android:onClick="click"  
            android:text="Test"  
            android:textSize="28sp" />  
  
    </LinearLayout>  
  
  
</LinearLayout>  

scale.xml

[html] view plain copy <?xml version="1.0" encoding="utf-8"?>  
<scale xmlns:android="http://schemas.android.com/apk/res/android"  
    android:duration="2000"  
    android:fromXScale="1.0"  
    android:fromYScale="1.0"  
    android:pivotX="50%"  
    android:pivotY="50%"  
    android:toXScale="8.0"  
    android:toYScale="8.0"></scale>  

java code

[html] view plain copy public void click(View view) {  
        Toast.makeText(this, "onClick", Toast.LENGTH_LONG).show();  
        Animation animation = AnimationUtils.loadAnimation(this, R.anim.scale);  
        view.startAnimation(animation);  
    }