HandleMouseDownAsync Method

Occurs when the OnToolMouseDown event is handled.

Syntax

C#
Visual Basic (Declaration)

protected virtual Task HandleMouseDownAsync( 
   MapViewMouseButtonEventArgs e
)

Protected Overridable Function HandleMouseDownAsync( _
   ByVal e As MapViewMouseButtonEventArgs _
) As Task

Parameters

e: A MapViewMouseButtonEventArgs that contains the event data.

Return Value

A Task that represents a mouse down event.

Remarks

This method is intended to perform asynchronous operations associated with a mouse down event. It will be called if you override the OnToolMouseDown virtual method and set the handled property on the MapViewMouseButtonEventArgs to true.

Example

Create a tool that allows you to click in the view and return the point in map coordinates that was clicked.

/*

   Copyright 2018 Esri

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

   See the License for the specific language governing permissions and
   limitations under the License.

*/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using ArcGIS.Desktop.Mapping;
using ArcGIS.Desktop.Framework.Threading.Tasks;

namespace Examples
{
  internal class GetMapCoordinates : MapTool
  {
    protected override void OnToolMouseDown(MapViewMouseButtonEventArgs  e)
    {
      if (e.ChangedButton == System.Windows.Input.MouseButton.Left)
        e.Handled = true; //Handle the event args to get the call to the corresponding async method
    }

    protected override Task HandleMouseDownAsync(MapViewMouseButtonEventArgs e)
    {
      return QueuedTask.Run(() =>
      {
        //Convert the clicked point in client coordinates to the corresponding map coordinates.
        var mapPoint = MapView.Active.ClientToMap(e.ClientPoint);
        ArcGIS.Desktop.Framework.Dialogs.MessageBox.Show(string.Format("X: {0} Y: {1} Z: {2}",
                       mapPoint.X, mapPoint.Y, mapPoint.Z), "Map Coordinates");
      });
    }
  }
}

Requirements

Target Platforms: Windows 10, Windows 8.1

Reference

MapTool Class
MapTool Members