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
这样做:
ImageView imgIcon = findViewById(R.id.imgIcon);
GradientDrawable backgroundGradient = (GradientDrawable)imgIcon.getBackground();
backgroundGradient.setColor(getResources().getColor(R.color.yellow));
其他回答
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
}
}
注意:答案已经更新，以涵盖背景是ColorDrawable实例的场景。谢谢泰勒·普法夫指出这一点。
可绘制对象是一个椭圆形，是ImageView的背景
使用getBackground()从imageView获取Drawable:
Drawable background = imageView.getBackground();
检查通常的嫌疑:
if (background instanceof ShapeDrawable) {
// cast to 'ShapeDrawable'
ShapeDrawable shapeDrawable = (ShapeDrawable) background;
shapeDrawable.getPaint().setColor(ContextCompat.getColor(mContext,R.color.colorToSet));
} else if (background instanceof GradientDrawable) {
// cast to 'GradientDrawable'
GradientDrawable gradientDrawable = (GradientDrawable) background;
gradientDrawable.setColor(ContextCompat.getColor(mContext,R.color.colorToSet));
} else if (background instanceof ColorDrawable) {
// alpha value may need to be set again after this call
ColorDrawable colorDrawable = (ColorDrawable) background;
colorDrawable.setColor(ContextCompat.getColor(mContext,R.color.colorToSet));
}
简洁版:
Drawable background = imageView.getBackground();
if (background instanceof ShapeDrawable) {
((ShapeDrawable)background).getPaint().setColor(ContextCompat.getColor(mContext,R.color.colorToSet));
} else if (background instanceof GradientDrawable) {
((GradientDrawable)background).setColor(ContextCompat.getColor(mContext,R.color.colorToSet));
} else if (background instanceof ColorDrawable) {
((ColorDrawable)background).setColor(ContextCompat.getColor(mContext,R.color.colorToSet));
}
注意，空检查不是必需的。
但是，如果在其他地方使用可绘制对象，则应该在修改它们之前对它们使用mutate()。(默认情况下，从XML加载的可绘制对象共享相同的状态。)
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")
希望这对有同样问题的人有所帮助
GradientDrawable gd = (GradientDrawable) YourImageView.getBackground();
//To shange the solid color
gd.setColor(yourColor)
//To change the stroke color
int width_px = (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, youStrokeWidth, getResources().getDisplayMetrics());
gd.setStroke(width_px, yourColor);
这是对我有效的解决方案……也写在另一个问题里: 如何动态改变形状颜色?
//get the image button by id
ImageButton myImg = (ImageButton) findViewById(R.id.some_id);
//get drawable from image button
GradientDrawable drawable = (GradientDrawable) myImg.getDrawable();
//set color as integer
//can use Color.parseColor(color) if color is a string
drawable.setColor(color)
