# MinMaxZoomPreference class

地图最大最小缩放级别的封装对象

## Constructors

MinMaxZoomPreference (double minZoom, double maxZoom)
  为地图创建一个不可变的最大最小缩放范围 当 `minZoom` > `maxZoom`时，会触发断言
  const

## Properties

hashCode → int
  The hash code for this object. [...]
  read-only, override
maxZoom → double
  最大zoomLevel
  final
minZoom → double
  最小zoomLevel
  final
runtimeType → Type
  A representation of the runtime type of the object.
  read-only, inherited

## Methods

noSuchMethod (Invocation invocation) → dynamic
  Invoked when a non-existent method or property is accessed. [...]
  inherited
toJson () → dynamic
  JSON序列化.
toString () → String
  Returns a string representation of this object.
  override

## Operators

operator == (dynamic other) → bool
  The equality operator. [...]
  override

## Constants

defaultPreference → const MinMaxZoomPreference
  高德地图默认zoomLevel的范围.
  `const MinMaxZoomPreference(3, 20)`