首先自定义view需要重写onDraw方法，处理wrap_content/padding 的问题

加入自定义参数：

• attrs.xml中

<resources>
    <declare-styleable name="MyHorizontalListView">
        <attr name="myDividerWidth" format="dimension" />
        <attr name="android:divider" />
        <attr name="android:requiresFadingEdge" />
        <attr name="android:fadingEdgeLength" />
    </declare-styleable>
</resources>

• 代码中获取数值

private void retrieveXmlConfiguration(Context context, AttributeSet attrs) {
        if (attrs != null) {
            TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.MyHorizontalListView);

            // Get the provided drawable from the XML
            final Drawable d = a.getDrawable(R.styleable.MyHorizontalListView_android_divider);
            if (d != null) {
                // If a drawable is provided to use as the divider then use its intrinsic width for the divider width
                setDivider(d);
            }

            // If a width is explicitly specified then use that width
            final int dividerWidth = a.getDimensionPixelSize(R.styleable.MyHorizontalListView_myDividerWidth, 0);
            if (dividerWidth != 0) {
                setDividerWidth(dividerWidth);
            }

            a.recycle();
        }
    }

• 使用自定义View

 <com.xxtoutiao.xxtt.view.MyHorizontalListView
                android:id="@+id/home_myHorizontalListView"
                android:layout_width="match_parent"
                android:layout_height="44dp"
                android:layout_toRightOf="@+id/home_avatar"
                android:layout_toLeftOf="@+id/set_channel"
                app:tabMode="scrollable" />

xml中：xmlns:app=http://schemas.android.com/apk/res-auto

app:是自定义属性的前缀，当然可以换其他名字，但是CircleView中使用自定义属性了，比如：app：circle_color＝ “@color/light_green”

也可以写为
xmlns:app=http://schemas.android.com/apk/com.xxtoutiao.xxtt

自定义view不要忘记wrap_content时的处理