使用google api测量3个标记之间的距离

Question

I am using react js and I am getting coordinates from user input. Now I want to calculate the total distance in miles between those coordinates. eg 51.5035914, -0.1193578 51.5031346, -0.1193844 51.5038217, -0.1282733

So the distance from point a to b + point b to c.

PS. In above example I added only 3 points but it can be 30 or more

Answer 1

If you want to get the distance and time duration to travel between your coordinates, you can use Google Maps Platform API's Distance Matrix API .

To do this, you can get the distance/duration between point A and point B in one Distance Matrix request first and store it in a variable. Then get the distance/duration between point B and point C in another request and add it in the same variable too.

Here is a snippet of a code that shows the Distance Matrix request:

    var service = new google.maps.DistanceMatrixService;
    var orig = this.state.input;
    var dest = this.state.destination;

    service.getDistanceMatrix({
          origins: [orig],
          destinations: [dest],
          travelMode: 'DRIVING',
          unitSystem: google.maps.UnitSystem.METRIC,
          avoidHighways: false,
          avoidTolls: false
        }, (response, status) => {
          if (status !== 'OK') { 
            alert('Error was: ' + status);
          } else {
            var origins = response.originAddresses;
            var destinations = response.destinationAddresses;

            //Loop through the elements row to get the value of duration and distance
            for (var i = 0; i < origins.length; i++) {
              var results = response.rows[i].elements;
              for (var j = 0; j < results.length; j++) {
              var element = results[j];
              var distanceString = element.distance.text;
              var durationString = element.duration.text;

              //add new value to the previousValue 
              this.setState ({
                distance: this.state.distance + parseInt(distanceString, 10)
                });
              console.log(this.state.distance);
              this.setState ({
                duration: this.state.duration + parseInt(durationString, 10)
                });
                console.log(this.state.duration);
               }
             }
          }
          });

Hope this helps!

Answer 2

I am using react js and I am getting coordinates from user input. Now I want to calculate the total distance in miles between those coordinates. eg 51.5035914, -0.1193578 51.5031346, -0.1193844 51.5038217, -0.1282733

So the distance from point a to b + point b to c.

PS. In above example I added only 3 points but it can be 30 or more