Unity ошибка cs0234

I’m trying to make a simple button perform an action when pressed. Initially I was using vscode, but as I couldn’t solve the problem, I switched to visual studio 2017. For some reason the error persists.

The button has been removed from this link:

https://www.c-sharpcorner.com/article/unity-change-scene-on-button-click-using-c-sharp-scripts-in-unity/

Button code (internet sketch):

using System.Collections;  
using System.Collections.Generic;  
using UnityEngine;  
using UnityEngine.SceneManagement;

public class SceneChanger: MonoBehaviour {  
    public void Scene1() {  
        SceneManager.LoadScene("Scene1");  
    }  
    public void Scene2() {  
        SceneManager.LoadScene("Scene2");  
    }  
    public void Scene3() {  
        SceneManager.LoadScene("Scene3");  
    }  
}

Button code (my code):

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;
using System.Windows.Forms;

public class botaoJogar : MonoBehaviour
{
    public Button btn_Jogar;

    void Start()
    {
        Button btn = btn_Jogar.GetComponent<Button>();
        btn.onClick.AddListener(TaskOnClick);
    }

    void TaskOnClick()
    {
        Debug.Log("You have clicked the button!");
    }
}

Image of the construction in unity:

Before, I was able to solve the CS0236 error using the answers from this link:

https://stackoverflow.com/questions/2883505/the-type-or-namespace-name-button-could-not-be-found-are-you-missing-a-using

The answer says to add the line using System.Windows.Forms; to the button code, but for some reason, now in visual studio, this error doesn’t go away.

Errors:

Assetsbotajogar.cs(4,22): error CS0234: The type or namespace name
‘Forms’ does not exist in the namespace ‘System.Windows’ (are you
missing an assembly reference?)

Assetsbotajogar.cs(8,12): error CS0246: The type or namespace name
‘Button’ could not be found (are you missing a using directive or an
assembly reference?)

Some community links, which I accessed:

https://stackoverflow.com/questions/42000798/how-do-i-add-assembly-references-in-visual-studio-code

https://stackoverflow.com/questions/49805204/adding-reference-to-another-project-from-visual-studio-code

https://stackoverflow.com/questions/2883505/the-type-or-namespace-name-button-could-not-be-found-are-you-missing-a-using

https://stackoverflow.com/questions/47412796/system-windows-forms-assembly-reference-in-vs-code

https://stackoverflow.com/questions/46582847/creating-a-windows-forms-application-in-c-sharp-using-dotnet-new

https://stackoverflow.com/questions/40562192/windows-form-application-on-visual-studio-code

https://stackoverflow.com/questions/48496542/forms-does-not-exist-in-the-namespace-system-windows

Other links:

https://docs.microsoft.com/en-us/visualstudio/ide/how-to-add-or-remove-references-by-using-the-reference-manager?view=vs-2019

https://docs.microsoft.com/pt-br/dotnet/csharp/language-reference/compiler-messages/cs0246

I don’t know what to do anymore, I feel like I tried to do everything I could, but windows forms simply don’t work. Visual studio 2017 has no bugs, just unity.

Installation I did in visual studio 2017:

Sometimes, when you add Flexbox4Unity to an existing project, Unity will generate this error in your console:

error CS0234: The type or namespace name ‘EventSystems’ does not exist in the namespace

This is caused by a small bug in Unity itself: they keep changing their internal UI classes in incompatible ways (in 2020 Unity is now onto the third complete rewrite for the Unity UI system, each time they give it a new name and make it incompatible with what they provided before).

Fortunately this is usually easy to fix – you just need to re-import Unity’s own UnityUI library (it’s unfortunate that they didn’t fix this themselves, and do the import automatically).

1. In the Project view, open the Packages section
2. Find the “Unity UI” folder
3. Right click “Unity UI” folder and select “Re-import”

Re-importing should take 5-10 seconds, after which your compiler error should have disappeared.

I’am new in Unity, so don’t be angry)

I tried to build my game, but I’ve got those errors:

-AssetsScriptsPlayerMovement.cs(5,19): error CS0234: The type or namespace name ‘WSA’ does not exist in the namespace ‘UnityEngine’ (are you missing an assembly reference?)

-AssetsScriptsSpawnMovePoint.cs(4,19): error CS0234: The type or namespace name ‘Build’ does not exist in the namespace ‘UnityEditor’ (are you missing an assembly reference?)

-Error building Player because scripts had compiler errors

using System.Collections;
using System.Collections.Generic;
using System.Linq;
using UnityEditor.Build.Reporting; // Problem Line
using UnityEngine;
using UnityEngine.SceneManagement;


public class SpawnMovePoint : MonoBehaviour
{
    public Transform left, right, _point;
    float MinX, MaxX;
 


    public void Start()
    {
        MinX = left.position.x;
        MaxX = right.position.x;
    }



    public void CreatePoint()
    {
        _point.position = new Vector3(Random.Range(MinX, 
  MaxX),_point.position.y,_point.position.z);
    }
}

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using UnityEditor;
using UnityEngine.WSA;//Problem Line


public class PlayerMovement : MonoBehaviour 

What should I do to fix them?
How can I make these references?
What does it mean, what ‘Build’ does not exist in ‘UnityEditor’?