A
Property whose value is lazily evaluated by a callback function.
| 参数名称 | 类型 | 描述信息 |
|---|---|---|
callback |
CallbackProperty.Callback | The function to be called when the property is evaluated. |
isConstant |
boolean |
true when the callback function returns the same value every time, false if the value will change. |
成员(属性)
readonly definitionChanged : Event
Gets the event that is raised whenever the definition of this property changes.
The definition is changed whenever setCallback is called.
Gets a value indicating if this property is constant.
方法
Compares this property to the provided property and returns
true if they are equal, false otherwise.
| 参数名称 | 类型 | 描述信息 |
|---|---|---|
other |
Property | 可选 The other property. |
返回值:
true if left and right are equal, false otherwise.
Gets the value of the property.
| 参数名称 | 类型 | 默认值 | 描述信息 |
|---|---|---|---|
time |
JulianDate |
JulianDate.now()
|
可选 The time for which to retrieve the value. If omitted, the current system time is used. |
result |
object | 可选 The object to store the value into, if omitted, a new instance is created and returned. |
返回值:
The modified result parameter or a new instance if the result parameter was not supplied or is unsupported.
Sets the callback to be used.
| 参数名称 | 类型 | 描述信息 |
|---|---|---|
callback |
CallbackProperty.Callback | The function to be called when the property is evaluated. |
isConstant |
boolean |
true when the callback function returns the same value every time, false if the value will change. |
定义的类型
A function that returns the value of the property.
| 参数名称 | 类型 | 默认值 | 描述信息 |
|---|---|---|---|
time |
JulianDate |
JulianDate.now()
|
可选 The time for which to retrieve the value. If omitted, the current system time is used. |
result |
object | 可选 The object to store the value into. If omitted, the function must create and return a new instance. |
返回值:
The modified result parameter, or a new instance if the result parameter was not supplied or is unsupported.