Arcgis api for javascript distance and Area Calculation

In the previous experiment, distance calculation and area calculation had been a problem and it took a long time to find the cause of the problem. Now it is successfully completed.

1. lengthParams. polylines = [geometry];

2. this. outSR = new esri. SpatialReference ({wkid: 102113 });
GeometryService. project ([geometry], this. outSR, function (geometry ){
GeometryService. simplify (geometry, function (simplifiedGeometries ){
AreasAndLengthParams. polygons = simplifiedGeometries;
AreasAndLengthParams. polygons [0]. spatialReference = new esri. SpatialReference (102113 );
GeometryService. areasAndLengths (areasAndLengthParams );
});
});

In addition, the area calculation is different from the distance calculation. projection transformation is required! Because our base map coordinate system is 4326

// Measure function measutreLength () {toolbar. activate (esri. toolbars. draw. POLYLINE);} function measutreArea () {toolbar. activate (esri. toolbars. draw. POLYGON );}

// Metering function doMeasure (geometry) {// display style measuregeometry = geometry; toolbar for more types. deactivate (); switch (geometry. type) {case "polyline": var symbol = new esri. symbol. simpleLineSymbol (esri. symbol. simpleLineSymbol. STYLE_SOLID, new dojo. color ([0, 0, 0]), 2); break; case "polygon": var symbol = new esri. symbol. simpleFillSymbol (esri. symbol. simpleFillSymbol. STYLE_NONE, new esri. symbol. simpleLineSymbol (esri. symbol. simpleLineSymbol. STYLE_DASHDOT, new dojo. color ([255, 0, 0]), 2), new dojo. color ([255,255, 0, 0.25]); break;} // sets the style var graphic = new esri. graphic (geometry, symbol); // clears the last drawing content myMap. graphics. clear (); myMap. graphics. add (graphic); // call projectComplete MeasureGeometry (geometry) after projection conversion is complete;} // call function MeasureGeometry (geometry) after projection conversion is complete) {// if the line type is used, perform lengths distance measurement if (geometry. type = "polyline") {var lengthParams = new esri. tasks. lengthsParameters (); lengthParams. polylines = [geometry]; lengthParams. lengthUnit = esri. tasks. geometryService. UNIT_METER; lengthParams. geodesic = true; lengthParams. polylines [0]. spatialReference = new esri. spatialReference (4326); geometryService. lengths (lengthParams); dojo. connect (geometryService, "onLengthsComplete", outputDistance);} // if it is of the surface type, perform the simplify operation before calculating the area else if (geometry. type = "polygon") {var areasAndLengthParams = new esri. tasks. areasAndLengthsParameters (); areasAndLengthParams. lengthUnit = esri. tasks. geometryService. UNIT_METER; areasAndLengthParams. areaUnit = esri. tasks. geometryService. UNIT_SQUARE_METERS; this. outSR = new esri. spatialReference ({wkid: 102113}); geometryService. project ([geometry], this. outSR, function (geometry) {geometryService. simplify (geometry, function (simplifiedGeometries) {areasAndLengthParams. polygons = simplifiedGeometries; areasAndLengthParams. polygons [0]. spatialReference = new esri. spatialReference (102113); geometryService. areasAndLengths (areasAndLengthParams) ;}); dojo. connect (geometryService, "onAreasAndLengthsComplete", outputAreaAndLength) ;}// display the measurement distance function outputDistance (result) {var CurX = measuregeometry. paths [0] [measuregeometry. paths [0]. length-1] [0]; var CurY = measuregeometry. paths [0] [measuregeometry. paths [0]. length-1] [1]; var CurPos = new esri. geometry. point (CurX, CurY, myMap. spatialReference); myMap. infoWindow. setTitle ("distance measurement"); myMap. infoWindow. setContent ("test duration:"+ ParseInt (String (result. lengths [0]) +" meters"); MyMap. infoWindow. show (CurPos);} // display the measurement area function outputAreaAndLength (result) {var CurX = (measuregeometry. _ extent. xmax + measuregeometry. _ extent. xmin)/2; var CurY = (measuregeometry. _ extent. ymax + measuregeometry. _ extent. ymin)/2 var CurPos = new esri. geometry. point (CurX, CurY, myMap. spatialReference); myMap. infoWindow. setTitle ("Area Measurement"); myMap. infoWindow. setContent ("area:"+ ParseInt (String (result. areas [0]) +" m2Perimeter: "+ parseInt (String (result. lengths [0]) + "meter"); myMap. infoWindow. show (CurPos); // alert ("Area:" + dojo. number. format (result. areas [0]) + "square meter" + "Length:" + dojo. number. format (result. lengths [0]) + "meter ");}