how do I change the solid color of a ripple drawable?

Question

<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
        android:color="?android:attr/colorControlHighlight">
    <item>
        <selector>
            <item android:state_selected="true">
                <layer-list>
                    <item android:left="-5dp"
                          android:top="-5dp"
                          android:right="-5dp">
                        <shape android:shape="rectangle">
                            <stroke android:width="3dp"
                                    android:color="@android:color/white"/>
                            <solid android:color="@android:color/transparent"/>
                        </shape>
                    </item>
                </layer-list>
            </item>
            <item android:state_selected="false">
                <shape android:shape="rectangle">
                    <solid android:color="@android:color/transparent"/>
                </shape>
            </item>

        </selector>
    </item>
</ripple>

here is my ripple drawable and i want to change the state_selected, solid color.

code i've tried:

RippleDrawable rippleDrawable = (RippleDrawable) textView.getBackground(); // assumes bg is a RippleDrawable
        int[][] states = new int[][]{new int[]{android.R.attr.state_selected}};
        int[] colors = new int[]{R.color.white}; 
        ColorStateList colorStateList = new ColorStateList(states, colors);
        rippleDrawable.setColor(colorStateList);

unfortuantely it doesn't work.. what am I missing and is this possible?

Answer 1

您应该为项目添加一个 id 以通过 java/kotlin 访问它们。
检查此背景 XML 文件

<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
    android:color="#e0e0e0">
   <item android:id="@+id/fab_shape">
      <shape xmlns:android="http://schemas.android.com/apk/res/android"
         android:shape="rectangle">
         <corners android:radius="25dp" />
        <solid android:color="@color/colorAccent" />
     </shape>
  </item>
</ripple>

为了改变这个的纯色，在constraintLayout背景上，这个drawable XML被应用

val background = constraintLayout.background as RippleDrawable
val bgShape = background.findDrawableByLayerId(R.id.fab_shape) as GradientDrawable
bgShape.color = color

供参考阅读此