属性'distanceBetween'在类型'{new（）：Location;原型：位置； }'

Question

我想用打字稿写this代码：

我得到正确的visibleRegion，但是我不明白如何编写代码Location.distanceBetween（..）来计算距离。

我有此代码：

this.gMap = event.object.gMap;
var visibleRegion = this.gMap.getProjection().getVisibleRegion();
var farRight = visibleRegion.farRight;
var farLeft = visibleRegion.farLeft;
var nearRight = visibleRegion.nearRight;
var nearLeft = visibleRegion.nearLeft;
var diagonalDistance = new float[1]; //Cannot find name 'float'.ts(2304)

var farLeft = visibleRegion.farLeft;
var nearRight = visibleRegion.nearRight;

Location.distanceBetween( //Property 'distanceBetween' does not exist on type '{ new (): Location; prototype: Location; }'.ts(2339)
  farLeft.latitude,
  farLeft.longitude,
  nearRight.latitude,
  nearRight.longitude,
  diagonalDistance
);

return diagonalDistance[0] / 2; 

请问您有什么想法吗？我不会用打字稿代码写。 Nativescript / Angular