当我想在Kotlin中为textColor
的{{1}}制作动画时:
TextView
发生此错误:
val animator = ObjectAnimator.ofInt(myTextView, "textColor", 0xFF8363FF, 0xFFC953BE)
似乎无法将值Error:(124, 43) None of the following functions can be called with the arguments supplied:
public open fun <T : Any!> ofInt(target: TextView!, xProperty: Property<TextView!, Int!>!, yProperty: Property<TextView!, Int!>!, path: Path!): ObjectAnimator! defined in android.animation.ObjectAnimator
public open fun <T : Any!> ofInt(target: TextView!, property: Property<TextView!, Int!>!, vararg values: Int): ObjectAnimator! defined in android.animation.ObjectAnimator
public open fun ofInt(target: Any!, propertyName: String!, vararg values: Int): ObjectAnimator! defined in android.animation.ObjectAnimator
public open fun ofInt(target: Any!, xPropertyName: String!, yPropertyName: String!, path: Path!): ObjectAnimator! defined in android.animation.ObjectAnimator
public open fun ofInt(vararg values: Int): ValueAnimator! defined in android.animation.ObjectAnimator
和0xFF8363FF
强制转换为Kotlin中的0xFFC953BE
,但是,它在Java中是正常的:
Int
有什么想法吗?提前谢谢。
答案 0 :(得分:14)
0xFF8363FF
(以及0xFFC953BE
)是Long
,而不是Int
。
您必须明确地将它们转换为Int
:
val animator = ObjectAnimator.ofInt(myTextView, "textColor", 0xFF8363FF.toInt(), 0xFFC953BE.toInt())
关键是0xFFC953BE
的数值为4291384254
,因此应将其存储在Long
变量中。但这里的高位是一个符号位,表示一个负数:-3583042
,可以存储在Int
中。
这就是两种语言之间的区别。在 Kotlin 中,您应该添加-
符号来表示否定Int
,这在 Java 中是不正确的:
// Kotlin
print(-0x80000000) // >>> -2147483648 (fits into Int)
print(0x80000000) // >>> 2147483648 (does NOT fit into Int)
// Java
System.out.print(-0x80000000); // >>> -2147483648 (fits into Integer)
System.out.print(0x80000000); // >>> -2147483648 (fits into Integer)