Question How to get value of component from Main Camera?

Hello,

I'm trying to get a value of a component of the Main Camera. The Main Camera has a MainCamera tag.
But i can't reach the value of the longitude.

Code (CSharp):

1.     public GameObject test;
2.     void Update()
3.     {
4.     test = gameObject.FindWithTag("MainCamera").GetComponent("ArcGIS Location").longitude;
5.     Debug.Log(test);
6. }

I use (" ") because of the spaces in the component name, but i don't know for sure if thats the correct way.

Hope someone can give me a tip.

 

Sure, there's a bit of a shorthand to get the main camera.

 Camera.main

will get the camera with the Main Camera tag.

For the GetComponent you're close, but you want

GetComponent<ArcGISLocation>();

Something like this:

Code (CSharp):

1. using UnityEngine;
2.  
3. public class Testing : MonoBehaviour
4. {
5.     void Start()
6.     {
7.         Camera mainCamera = Camera.main;
8.         ArcGISLocation gisLocation = mainCamera.GetComponent<ArcGISLocation>();
9.         float longitude = gisLocation.longitude;
10.         Debug.Log(longitude);
11.     }
12. }

Also, generally you'd cache GetComponent calls and any Find stuff in Start or Awake as Update will do that every frame. It can get costly if you have a lot of these scripts in your scene, so do it once and use as often as you want. Something like:

Code (CSharp):

1. using UnityEngine;
2.  
3. public class Testing : MonoBehaviour
4. {
5.     private ArcGISLocation gisLocation;
6.  
7.     private void Start()
8.     {
9.         gisLocation = Camera.main.GetComponent<ArcGISLocation>();
10.     }
11.  
12.     private void Update()
13.     {
14.         if (Input.GetKeyDown(KeyCode.F))
15.         {
16.             Debug.Log(gisLocation.longitude);
17.         }
18.     }
19. }

Make sure your ArcGISLocation doesn't have spaces in either the file name or the class. It's fine if it shows spaces in the name of the script in the inspector. It's just Unity trying to format it nicely so it's more readable.

Make sure longitude is public or has a public getter.

 

Really, just don't write code like this. It's so unnecessary most of the time.

More information: https://starmanta.gitbooks.io/unitytipsredux/content/first-question.html

More information: https://forum.unity.com/threads/why-cant-i-find-the-other-objects.1360192/#post-8581066

In general, DO NOT use Find-like or GetComponent/AddComponent-like methods unless there truly is no other way, eg, dynamic runtime discovery of arbitrary objects. These mechanisms are for extremely-advanced use ONLY.

If something is built into your scene or prefab, make a script and drag the reference(s) in. That will let you experience the highest rate of The Unity Way(tm) success of accessing things in your game.

Remember the first rule of GameObject.Find():

Do not use GameObject.Find();

 

Hello, i think this is a good way, but i get the error message that the ArcGISLocation is missing. I think of the space in the component name.


Also, generally you'd cache GetComponent calls and any Find stuff in Start or Awake as Update will do that every frame. It can get costly if you have a lot of these scripts in your scene, so do it once and use as often as you want. Something like:

Code (CSharp):

1. using UnityEngine;
2.  
3. public class Testing : MonoBehaviour
4. {
5.     private ArcGISLocation gisLocation;
6.  
7.     private void Start()
8.     {
9.         gisLocation = Camera.main.GetComponent<ArcGISLocation>();
10.     }
11.  
12.     private void Update()
13.     {
14.         if (Input.GetKeyDown(KeyCode.F))
15.         {
16.             Debug.Log(gisLocation.longitude);
17.         }
18.     }
19. }

 

What do you mean missing? You mean a Null Reference exception?

That would imply the component is not on the camera, or you're trying to get the component from the wrong game object.

 

error CS0246: The type or namespace name 'ArcGISLocation' could not be found (are you missing a using directive or an assembly reference?) but the ArcGIS Location component is in the
Main Camera.

When i use Camera.main.GetComponent<Transform>(); And then Debug.Log(gisLocation.position.y) i get a normal reaction. And Transform is also under the Main Camera.

 

Does your IDE not help auto complete the right component name?

Or I would look at the documentation of whatever tool you're using to see what the actual component names are.

 

Thanks. I opened the component script and found there the public class name: ArcGISLocationComponent
I tried that name with Debug.Log(gisLocation.Position.Y); And YES i get

Now i can call the position of the player. Because i think the position changed when the player/camera moves.

 

In the script you quote in post #5, change all your ArcGISLocation to ArcGISLocationComponent to match the class name.

Not sure why the inspector is saying one thing and the class name is something else. Kinda strange.

 

Yeah strange. Maybe that's a setting in the ArcGIS SDK plugin i use. I also thought the component name must always be the same as the class name. Looking back it was a easy fix

 

You're missing the necessary using statements in that example. Your IDE should have suggested them to you.

 

I have another little question. With this code i can access x and y, but not Spatial Ref WKID

Code (CSharp):

1. var GisLocation = CoorXY.GetComponent<ArcGISLocationComponent>();
2.         var GisX = GisLocation.Position.X.ToString();

I tested with:

Code (CSharp):

1. var GisLocation = CoorXY.GetComponent<ArcGISLocationComponent>();
2.         var GisX = GisLocation.Position.SpatialRefWKID.ToString();

cant found it