Android LinearLayout，RelativeLayout相对，绝对布局的100%适配

1).我们先自定义一个类来继承RelativeLayout，其中最主要是实现onMeasure（）方法和onLayout（）方法！通过generateLayoutParams（）来获取下面的attr.xml中的属性比例值，

然后再在onMeasure()方法中 ViewGroup.LayoutParams params = child.getLayoutParams();来获取占空比！从而达到子控件是主控件的多少比例大小！

  1 package watch.devond.okhttp;
  2 
  3 import android.content.Context;
  4 import android.content.res.TypedArray;
  5 import android.util.AttributeSet;
  6 import android.view.View;
  7 import android.view.ViewGroup;
  8 import android.widget.RelativeLayout;
  9 
 10 public class PercentRelativeLayout extends RelativeLayout {
 11 
 12     public PercentRelativeLayout(Context context) {
 13         super(context);
 14     }
 15 
 16     public PercentRelativeLayout(Context context, AttributeSet attrs) {
 17         super(context, attrs);
 18     }
 19 
 20     public PercentRelativeLayout(Context context, AttributeSet attrs, int defStyleAttr) {
 21         super(context, attrs, defStyleAttr);
 22     }
 23 
 24     /***
 25      * 测量容器的宽高
 26      * @param widthMeasureSpec
 27      * @param heightMeasureSpec
 28      */
 29     @Override
 30     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
 31         int width = View.MeasureSpec.getSize(widthMeasureSpec);
 32         int height = View.MeasureSpec.getSize(heightMeasureSpec);
 33         //测量子控件的宽高，然后进行改变
 34 
 35         int childCount = getChildCount();
 36         for(int i = 0;i < childCount;i++){
 37 
 38             float widthPercent = 0;
 39             float heightPercent = 0;
 40 
 41             View child = getChildAt(i);
 42             ViewGroup.LayoutParams params = child.getLayoutParams();
 43             if(params instanceof PercentRelativeLayout.LayoutParams){
 44                 widthPercent = ((LayoutParams) params).getWidthPercent();
 45                 heightPercent = ((LayoutParams) params).getHeihtPercent();
 46             }
 47             if(widthPercent != 0){
 48                 params.width = (int) (width * widthPercent);
 49 
 50                 params.height = (int) (height * heightPercent);
 51 
 52             }
 53         }
 54         super.onMeasure(widthMeasureSpec, heightMeasureSpec);
 55     }
 56 
 57     /***
 58      * 排版摆放控件
 59      * @param changed
 60      * @param l
 61      * @param t
 62      * @param r
 63      * @param b
 64      */
 65     @Override
 66     protected void onLayout(boolean changed, int l, int t, int r, int b) {
 67         super.onLayout(changed, l, t, r, b);
 68 
 69     }
 70 
 71     /**
 72      * @param attrs
 73      * @return
 74      */
 75     @Override
 76     public RelativeLayout.LayoutParams generateLayoutParams(AttributeSet attrs) {
 77 
 78         return new LayoutParams(getContext(),attrs);
 79     }
 80 
 81     class LayoutParams extends RelativeLayout.LayoutParams {
 82 
 83         private float widthPercent;
 84         private float heihtPercent;
 85 
 86         public float getWidthPercent() {
 87             return widthPercent;
 88         }
 89 
 90         public void setWidthPercent(float widthPercent) {
 91             this.widthPercent = widthPercent;
 92         }
 93 
 94         public float getHeihtPercent() {
 95             return heihtPercent;
 96         }
 97 
 98         public void setHeihtPercent(float heihtPercent) {
 99             this.heihtPercent = heihtPercent;
100         }
101 
102         public LayoutParams(Context c, AttributeSet attrs) {
103             super(c, attrs);
104             TypedArray array = c.obtainStyledAttributes(attrs,R.styleable.PercentRelativeLayout);
105             widthPercent = array.getFloat(R.styleable.PercentRelativeLayout_layout_widthPercent,widthPercent);
106             heihtPercent = array.getFloat(R.styleable.PercentRelativeLayout_layout_heihtPercent,heihtPercent);
107             array.recycle();
108         }
109 
110         public LayoutParams(int w, int h) {
111             super(w, h);
112         }
113 
114         public LayoutParams(ViewGroup.LayoutParams source) {
115             super(source);
116         }
117 
118         public LayoutParams(MarginLayoutParams source) {
119             super(source);
120         }
121 
122     }
123 }

2)在res文件的value文件中创建attr.xml文件如下：

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <!--百分比RelativeLayout-->
    <declare-styleable name="PercentRelativeLayout">
        <attr name="layout_widthPercent" format="float"> </attr>
        <attr name="layout_heihtPercent" format="float"> </attr>
    </declare-styleable>

</resources>

3）主界面的xml

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <watch.devond.okhttp.PercentRelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     xmlns:tools="http://schemas.android.com/tools"
 4     android:layout_width="match_parent"
 5     android:layout_height="match_parent"
 6     xmlns:app="http://schemas.android.com/apk/res-auto"
 7     android:gravity="center"
 8     tools:ignore="ResAuto">
 9 
10     <Button
11         android:layout_width="wrap_content"
12         android:layout_height="wrap_content"
13         android:text="Hello World!"
14         app:layout_widthPercent ="0.8"
15         app:layout_heihtPercent ="0.1"
16         />
17 
18 
19 </watch.devond.okhttp.PercentRelativeLayout>