Android LinearLayout，RelativeLayout相對，絕對布局的100%適配

1).我們先自定義一個類來繼承RelativeLayout，其中最主要是實現onMeasure（）方法和onLayout（）方法！通過generateLayoutParams（）來獲取下面的attr.xml中的屬性比例值，

然后再在onMeasure()方法中 ViewGroup.LayoutParams params = child.getLayoutParams();來獲取占空比！從而達到子控件是主控件的多少比例大小！

package watch.devond.okhttp;

import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RelativeLayout;

public class PercentRelativeLayout extends RelativeLayout {

    public PercentRelativeLayout(Context context) {
        super(context);
    }

    public PercentRelativeLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public PercentRelativeLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    /***
     * 測量容器的寬高
     * @param widthMeasureSpec
     * @param heightMeasureSpec
     */
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int width = View.MeasureSpec.getSize(widthMeasureSpec);
        int height = View.MeasureSpec.getSize(heightMeasureSpec);
        //測量子控件的寬高，然后進行改變

        int childCount = getChildCount();
        for(int i = 0;i < childCount;i++){

            float widthPercent = 0;
            float heightPercent = 0;

            View child = getChildAt(i);
            ViewGroup.LayoutParams params = child.getLayoutParams();
            if(params instanceof PercentRelativeLayout.LayoutParams){
                widthPercent = ((LayoutParams) params).getWidthPercent();
                heightPercent = ((LayoutParams) params).getHeihtPercent();
            }
            if(widthPercent != 0){
                params.width = (int) (width * widthPercent);

                params.height = (int) (height * heightPercent);

            }
        }
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    /***
     * 排版擺放控件
     * @param changed
     * @param l
     * @param t
     * @param r
     * @param b
     */
    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        super.onLayout(changed, l, t, r, b);

    }

    /**
     * @param attrs
     * @return
     */
    @Override
    public RelativeLayout.LayoutParams generateLayoutParams(AttributeSet attrs) {

        return new LayoutParams(getContext(),attrs);
    }

    class LayoutParams extends RelativeLayout.LayoutParams {

        private float widthPercent;
        private float heihtPercent;

        public float getWidthPercent() {
            return widthPercent;
        }

        public void setWidthPercent(float widthPercent) {
            this.widthPercent = widthPercent;
        }

        public float getHeihtPercent() {
            return heihtPercent;
        }

        public void setHeihtPercent(float heihtPercent) {
            this.heihtPercent = heihtPercent;
        }

        public LayoutParams(Context c, AttributeSet attrs) {
            super(c, attrs);
            TypedArray array = c.obtainStyledAttributes(attrs,R.styleable.PercentRelativeLayout);
            widthPercent = array.getFloat(R.styleable.PercentRelativeLayout_layout_widthPercent,widthPercent);
            heihtPercent = array.getFloat(R.styleable.PercentRelativeLayout_layout_heihtPercent,heihtPercent);
            array.recycle();
        }

        public LayoutParams(int w, int h) {
            super(w, h);
        }

        public LayoutParams(ViewGroup.LayoutParams source) {
            super(source);
        }

        public LayoutParams(MarginLayoutParams source) {
            super(source);
        }

    }
}

 

2)在res文件的value文件中創建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

<?xml version="1.0" encoding="utf-8"?>
<watch.devond.okhttp.PercentRelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:gravity="center"
    tools:ignore="ResAuto">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        app:layout_widthPercent ="0.8"
        app:layout_heihtPercent ="0.1"
        />


</watch.devond.okhttp.PercentRelativeLayout>