自定义控件——自定义视图属性

package com.example.l01myrect;


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

/**
 * Created by 袁磊 on 2017/2/6.
 */
public class MyRect extends View {
    public MyRect(Context context) {
        super(context);
    }

    public MyRect(Context context, AttributeSet attrs) {
        super(context, attrs);

        TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.MyView);

        int color = ta.getColor(R.styleable.MyView_rect_color, 0xffff0000);//红色
        setBackgroundColor(color);

        ta.recycle();//TypedArray调用结束后务必调用recycle()方法，否则这次的设定会对下次的使用造成影响
    }
}

<?xml version="1.0" encoding="utf-8"?>
<resources>  <!--根标签-->
    <declare-styleable name="MyView">  <!--定义若干个declare-styleable，name定义了变量的名称-->
        <attr name="rect_color" format="color" /> <!--自定义多个属性，name为名称，format为属性类型-->
    </declare-styleable>
</resources>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:yl="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <com.example.l01myrect.MyRect
        android:layout_width="100dp"
        android:layout_height="100dp"
        yl:rect_color="#ff0000ff" /> <!--蓝色-->
</LinearLayout>