我正在编辑，使问题更简单，希望有助于得到一个准确的答案。
假设我有如下椭圆形状:
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval">
<solid android:angle="270"
android:color="#FFFF0000"/>
<stroke android:width="3dp"
android:color="#FFAA0055"/>
</shape>
如何从一个活动类中以编程方式设置颜色?
当前回答
也许我来晚了。但是如果您正在使用Kotlin。有这样的方法
var gd = layoutMain.background as GradientDrawable
//gd.setCornerRadius(10)
gd.setColor(ContextCompat.getColor(ctx , R.color.lightblue))
gd.setStroke(1, ContextCompat.getColor(ctx , R.color.colorPrimary)) // (Strokewidth,colorId)
享受……
其他回答
我的Kotlin扩展函数版本基于上述答案与Compat:
fun Drawable.overrideColor_Ext(context: Context, colorInt: Int) {
val muted = this.mutate()
when (muted) {
is GradientDrawable -> muted.setColor(ContextCompat.getColor(context, colorInt))
is ShapeDrawable -> muted.paint.setColor(ContextCompat.getColor(context, colorInt))
is ColorDrawable -> muted.setColor(ContextCompat.getColor(context, colorInt))
else -> Log.d("Tag", "Not a valid background type")
}
}
我们可以创建这个kotlin函数。
fun View.updateViewBGSolidColor(colorString: String) {
when (val background: Drawable = this.background) {
is ShapeDrawable -> {
background.paint.color = Color.parseColor(colorString)
}
is GradientDrawable -> {
background.setColor(Color.parseColor(colorString))
}
is ColorDrawable -> {
background.color = Color.parseColor(colorString)
}
}
}
然后像下面这样使用它:
yourTextView.updateViewBGSolidColor("#FFFFFF")
这个问题之前已经回答过了，但是可以通过重写为kotlin扩展函数来实现现代化。
fun Drawable.overrideColor(@ColorInt colorInt: Int) {
when (this) {
is GradientDrawable -> setColor(colorInt)
is ShapeDrawable -> paint.color = colorInt
is ColorDrawable -> color = colorInt
}
}
这样做:
ImageView imgIcon = findViewById(R.id.imgIcon);
GradientDrawable backgroundGradient = (GradientDrawable)imgIcon.getBackground();
backgroundGradient.setColor(getResources().getColor(R.color.yellow));
GradientDrawable gd = new GradientDrawable(
GradientDrawable.Orientation.TOP_BOTTOM,
new int[] {0xFF616261,0xFF131313});
gd.setCornerRadius(0f);
layout.setBackgroundDrawable(gd);
