Android选择器改变颜色但不改变大小

Question

我正在尝试使用选择器为ViewPager实现一个简单的点指示器.

当页面改变时,点应该改变颜色和大小,但它们只改变颜色,而大小保持不变.

选择器:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true">
        <shape android:shape="oval">
             <size
               android:height="12dp"
               android:width="12dp"/>
            <solid android:color="@color/highlight"/>
        </shape>
    </item>
    <item>
        <shape android:shape="oval">
            <size
              android:height="6dp"
              android:width="6dp"/>
            <solid android:color="@color/light_grey"/>
        </shape>
    </item>
</selector>

用于布局

<ImageView xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:padding="@dimen/margin_2x"
  android:src="@drawable/dot_selector">
</ImageView>

在onCreate()中使用它来显示初始状态:

for (int i = 0; i < mPagerAdapter.getCount(); i++) {
    getLayoutInflater().inflate(R.layout.dot_indicator, viewPagerCountDots);
}
viewPagerCountDots.getChildAt(0).setSelected(true);

这看起来像预期的那样

但当我改变页面改变时的选择器状态...

@Override
public void onPageSelected(int position) {
    for (int i = 0; i < mPagerAdapter.getCount(); i++) {
        viewPagerCountDots.getChildAt(i).setSelected(i == position);
    }
}

.. ..看起来像这样:

使子项无效或ViewGroup不执行任何操作.有什么线索这里出了什么问题？

更新

正如Bartek Lipinski所建议的,对孩子调用requestLayout会修复它

@Override
public void onPageSelected(int position) {
    for (int i = 0; i < mPagerAdapter.getCount(); i++) {
        View dotView = viewPagerCountDots.getChildAt(i);
        dotView.setSelected(i == position);
        dotView.invalidate();
        dotView.requestLayout();
    }
}

Answer 1

requestLayout()在onPageSelected回调中添加电话:

@Override
public void onPageSelected(int position) {
    for (int i = 0; i < mPagerAdapter.getCount(); i++) {
        viewPagerCountDots.getChildAt(i).setSelected(i == position);
        viewPagerCountDots.getChildAt(i).requestLayout();
    }
}

编辑:

或者你可以改变你的drawable总是相同的大小,所以这就setSelected足够了:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true">
        <shape android:shape="oval">
            <size
                android:width="12dp"
                android:height="12dp"/>
            <solid android:color="@color/highlight"/>
        </shape>
    </item>
    <item>
        <layer-list>
            <item android:bottom="3dp"
                  android:left="3dp"
                  android:right="3dp"
                  android:top="3dp">
                <shape android:shape="oval">
                    <size
                        android:width="6dp"
                        android:height="6dp"/>
                    <solid android:color="@color/light_grey"/>
                </shape>
            </item>
        </layer-list>
    </item>
</selector>