android - TextView :shadowDx/Dy/Radius in dip?

Question

我们如何在 dip 中指定 TextView 的 shadowDx/Dy/Radius 值？现在我有:

<style name="foo">
  <item name="android:shadowDx">-1</item>
  <item name="android:shadowDy">-1</item>
  <item name="android:shadowRadius">1</item>
</style>

我似乎无法在这些地方指定“1dip”。除了在代码中设置它们并自己进行设备密度乘法之外，还有其他方法吗？

谢谢

Answer 1

我使用自定义 xml 属性创建了一个重写的 TextView 以方便地处理此问题。

也可作为库使用:https://github.com/rongi/text-view-shadow-dips

public class TextViewShadowDips extends TextView {

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

    final TypedArray attributes = context.obtainStyledAttributes(attrs, R.styleable.TextViewShadowDips);
    // App can crash on some devices if shadow radius is more than 25 pixels
    // On Samsung Galaxy S6 this crash happens when you copy a text from an input field
    // https://stackoverflow.com/questions/4866928/ranges-for-radius-in-shadowradius-and-visiblity-in-textview?lq=1
    final float shadowRadius = Math.min(
        attributes.getDimension(R.styleable.TextViewShadowDips_shadowRadius, 0f),
        25f
    );
    final float shadowDx = attributes.getDimension(R.styleable.TextViewShadowDips_shadowDx, 0f);
    final float shadowDy = attributes.getDimension(R.styleable.TextViewShadowDips_shadowDy, 0f);
    final int shadowColor = attributes.getColor(R.styleable.TextViewShadowDips_shadowColor, 0);
    if (shadowColor != 0) {
        setShadowLayer(shadowRadius, shadowDx, shadowDy, shadowColor);
    } else {
        getPaint().clearShadowLayer();
    }
    attributes.recycle();
}

“values”资源文件夹中的attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <declare-styleable name="TextViewShadowDips">
        <attr name="shadowRadius" format="dimension"/>
        <attr name="shadowDx" format="dimension"/>
        <attr name="shadowDy" format="dimension"/>
        <attr name="shadowColor" format="color"/>
    </declare-styleable>

</resources>

使用示例:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" >

    <my.package.name.TextViewShadowDips 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:shadowColor="#000000"
        app:shadowRadius="2dp"
        app:shadowDx="2dp"
        app:shadowDy="2dp"
        />

</RelativeLayout>