Develop Reference

C# function destroy doesn't function

So I'm trying to make a 2D Snake game in Unity, which is made from 4 different C# scripts.
In this particular I try to delete the Food which the snake eats but nothing happens (Its marked in the Code), and the other function works just fine. I don't even get an Error.
If you need the other scripts, I can send those as well.
public void SnakeMoved(Vector2Int snakeGridPosition)
{
if (snakeGridPosition == foodGridPosition)
{
Object.Destroy(foodGameObject);
SpawnFood();
}
}
I tried to see if the rest in the IF clause works and the rest is working perfectly. I don't know what I did wrong.
Code for the foodGameObject:
private void SpawnFood()
{
foodGridPosition = new Vector2Int(Random.Range(0, width), Random.Range(0, height));
GameObject foodGameObject = new GameObject("Food", typeof(SpriteRenderer));
foodGameObject.GetComponent<SpriteRenderer>().sprite = GameAssets.i.foodSprite;
foodGameObject.transform.position = new Vector3(foodGridPosition.x, foodGridPosition.y);
}

In Unity you cannot create game objects in code using new GameObject(...). Instead you need to instantiate these, like that:
GameObject instantiatedFood = Instantiate(new GameObject("Food", typeof(SpriteRenderer)));
Instead of new GameObject("Food", typeof(SpriteRenderer)) you could also pass a prefab here which you link in the editor.
This instantiation step makes sense because you can prepare and deal with GameObjects in code before actually spawning them in the world.

FindObjectsWithTag bringing back objects in random order in Unity?

I'm attempting to make a level select that requires as little upkeep as possible as I intend on adding updates to add more levels (Unity Scenes) in unity.
To account for this I'm attempting to get the level select to create buttons for each level in the Unity Build settings, and then create a template object from a prefab in which it can map buttons it creates onto.
I have it mostly working, but for some reason, it's mapping the buttons in the wrong order, I'm trying to go down to up and Unity appears to be grabbing the Gameobjects is a random order.
Here is my code:
private Scene[] levels;
private int currentButtonId = 1;
public Transform buttonsHolder;
public GameObject buttonPrefab;
public GameObject buttonSlotsPrefab;
private GameObject[] levelButtonSlots;
private int currentLevelSlot = 0;
private int numSlotsToMove = 0;
private void Start()
{
var sceneCount = SceneManager.sceneCountInBuildSettings;
levels = new Scene[sceneCount];
for (var i = 0; i < sceneCount; i++)
{
// Beginning Setup
levels[i] = SceneManager.GetSceneByBuildIndex(i);
// Look for Level Placement Slots
levelButtonSlots = GameObject.FindGameObjectsWithTag("Level Slot");
// If there aren't enough Level Placement Slots make more by creating a template
if(levelButtonSlots.Length < levels.Length)
{
GameObject buttonSlots = Instantiate(buttonSlotsPrefab);
buttonSlots.transform.position = new Vector2(0, 10 * numSlotsToMove);
numSlotsToMove++;
}
// Go get those new placement slots
levelButtonSlots = GameObject.FindGameObjectsWithTag("Level Slot");
// Create Button
GameObject currentButton = Instantiate(buttonPrefab, buttonsHolder);
// Move it to the next slot
currentButton.transform.position = levelButtonSlots[currentLevelSlot].transform.position;
currentLevelSlot++;
// Add Text to a new button
TextMeshProUGUI buttonText = currentButton.GetComponentInChildren<TextMeshProUGUI>();
buttonText.text = (currentButtonId.ToString());
// Setup what which scene clicking a button will do
ButtonManager buttonScript = currentButton.GetComponentInChildren<ButtonManager>();
buttonScript.sceneToLoad = currentButtonId;
currentButtonId++;
}
}
The buttonsHolder variable is set in the editor and is the canvas.
The buttonPrefab is a TextMeshPro button prefab I set in the editor, it has the level Buttons tag and a simple script that loads the specified scene when clicked.
And the buttonSlotsPrefab is a gameobject prefab that I set in the editor, it has the Button Placement Slot tag and it contains 8 other empty gameobjects each with the level slot tag, I use these 8 objects as the guides as to where the buttons should be placed on runtime.
Again, my goal is to place the buttons going from bottom to top, but instead, Unity spits out this on runtime for no apparent reason:
I'm sorry about the naming convention some variables have, I'm tired and stressed as I've been at this 2 two days straight. I will fix those up once I get things working.
After further testing, I have noticed that when I first create buttonSlotPrefab, everything works perfectly, however, after restarting Unity (Not changing any files) when I run the game again after a restart the order gets randomized. Could this be a bug in the Unity Engine?

If i understant your problem, you have a problem between number of button and slot: you have slot spaced on axis y and you havent always the levelsolt[0] at the bottom of screen, so
you could order (ascending or descending i dunno) the levelslot on y axis before creating button: i am using Linq so add using System.Linq;
if (levelButtonSlots.Any())//Same thing than levelButtonSlots.Length > 0
{
levelButtonSlots = GameObject.FindGameObjectsWithTag("Level Slot").OrderBy(go => go.transform.position.y).ToArray();
}
or
levelButtonSlots = GameObject.FindGameObjectsWithTag("Level Slot").OrderByDescending(go => go.transform.position.y).ToArray();
I have added a test if no value in array, but maybe the error doesnt exist, i havent tested that

Unity 2D sprite doesn't flip

I'm doing a platformer game with Unity 2D and I wanted to flip the character sprite left when the player move him left, but for some reasons it doesn't work. I tried to make this one script:
transform.rotation = new Vector3(0f, 180f, 0f);
but it didn't work. So then I wrote this:
transform.localScale = new Vector3(-0.35f, 0.35f, 1f); //the player's scale x and y are 0.35 by default
but it didn't work too. Then I found this error message in the console: NullReferenceException: Object reference not set to an instance of an object
UnityEditor.Graphs.Edge.WakeUp () (at C:/buildslave/unity/build/Editor/Graphs/UnityEditor.Graphs/Edge.cs:114).
What should I do? I'm doing this game for a game jam so I need to resolve this problem quickly. Thank you.
EDIT: I noticed that I can flip the sprite in the editor, but that I can't do that using scripts.

From this thread I found, it seems like an old bug from Unity's UnityEditor.Graphs.DLL code.
Try restarting Unity completely.
This bug seems to occur only in the editor, and not after a game is built, so you should be safe.

I haven't worked on any 2D Unity projects in a while but here is a piece of code I used to resolve that issue in the past. Let me know if it helps.
private void FlipSprite()
{
bool playerHasHorizontalSpeed = Mathf.Abs(myRigidBody.velocity.x) > Mathf.Epsilon;
if(playerHasHorizontalSpeed)
{
transform.localScale = new Vector2(Mathf.Sign(myRigidBody.velocity.x), 1f);
}
}

This is a bit old so be sure to let me know how this works. You'll need to finish the rest of the controls, but this should work.
public class SpriteFlipper : MonoBehaviour
{
// variable to hold a reference to our SpriteRenderer component
private SpriteRenderer mySpriteRenderer;
// This function is called just one time by Unity the moment the component loads
private void Awake()
{
// get a reference to the SpriteRenderer component on this gameObject
mySpriteRenderer = GetComponent<SpriteRenderer>();
}
// This function is called by Unity every frame the component is enabled
private void Update()
{
// if the A key was pressed this frame
if(Input.GetKeyDown(KeyCode.A))
{
// if the variable isn't empty (we have a reference to our SpriteRenderer
if(mySpriteRenderer != null)
{
// flip the sprite
mySpriteRenderer.flipX = true;
}
}
}
}

Unity project upgrade : Upgrade project from Unity4 to Unity5 Getcomponent issue when build

Hi I'm upgrade my unity game project from UNITY4.7.2 to UNITY2019.1.7f1 everything WORK ON UNITY EDITOR(UNITY2019.1.7f1) but after I'm build project to iPhoneX game isn't work for some function eg.FindGameObjectWithTag, GetComponent I'm check in code and found getcomponent is not work at calling time
I'm already solved this by add spawnArea prefab to inspector and call them but for another function that use GetComponent still not work.
please anybody suggest me about problem whem we call getcomponent problem.
I'm looking around my code, unity console and search in google too, and assume FindGameObjectWithTag, GetComponent and another code kind like those 2 have problem when upgrade unity4 to unity2019:
spawnPoint = GameObject.FindGameObjectWithTag(TagManager.spawnArea).transform;
if (currentVehicle != null) {
if(bigTruck)
DestroyImmediate(currentVehicle.transform.parent.gameObject);
else
DestroyImmediate(currentVehicle.gameObject);
}
GameObject vehicle = Instantiate(vehiclePrefabs[GameManager.instance.selectedCar], spawnPoint.position, spawnPoint.rotation) as GameObject;
currentVehicle = vehicle.GetComponent<BaseVehicle>();
if (currentVehicle == null) {
currentVehicle = vehicle.GetComponentInChildren<BaseVehicle>();
bigTruck = true;
} else {
bigTruck = false;
}
playerCamera.target = currentVehicle.transform;
playerCamera.vehicleFront = currentVehicle.transform.Find("Front");
In unity console when I use debug build they show "NullReferenceException: Object reference not set to an instance of an object." but I'm look around my code and not found any object that null reference, I test by compare with null eg.
if (currentVehicle == null) {
Debug.Log("currentVehicle is null");
}

Clear Editor Console logs from script

This is my script and I tried to make "" in case it's not one of the cases:
private void OnCollisionEnter(Collision collision)
{
if (collision.gameObject.name == "Platform")
Debug.Log("Touching Platform");
else Debug.Log("");
}
private void OnTriggerEnter(Collider other)
{
if (other.gameObject.name == "OnTop Detector")
{
Debug.Log("On Top of Platform");
GameObject findGo = GameObject.Find("ThirdPersonController");
GameObject findGo1 = GameObject.Find("Elevator");
findGo.transform.parent = findGo1.transform;
}
else Debug.Log("");
}
But this "" not working. It's not deleting the text from the console while the game is running. And also when i stop the game and running it again it keep showing the last text of the Debug.Log.
I want to clear it if none of the If's happen in my script.
I saw this answer:
Answer
But i'm not sure if this is what I need and how to use it. Make a new script ?
And also what about errors. If I clear the Log in the console it will delete also erorrs if there will be some ?
In this screenshot it's in state after I touched the platform and then moved away from it but the text still exist in the console log:

The Debug.ClearDeveloperConsole() function is used when you clear logs from an application that was built while Debug Build is enabled in your project. There is no official API for clearing the Editor log.
Most Editor functionality can be replicated with Reflection just like hiding Gizmos and toggling the Stats Panel. I was going to write one but found this one.
This should clear every log on the Console tab.
using System.Reflection;
public void ClearLog()
{
var assembly = Assembly.GetAssembly(typeof(UnityEditor.ActiveEditorTracker));
var type = assembly.GetType("UnityEditorInternal.LogEntries");
var method = type.GetMethod("Clear");
method.Invoke(new object(), null);
}
Now, you can call ClearLog(); in your else statements.
EDIT:
This has changed recently in about ~Unity 2017. Since it is done with reflection, I consider it to change again anytime if any class, variable or function used in this code is renamed by Unity. Below is the new way to do this:
public void ClearLog()
{
var assembly = Assembly.GetAssembly(typeof(UnityEditor.Editor));
var type = assembly.GetType("UnityEditor.LogEntries");
var method = type.GetMethod("Clear");
method.Invoke(new object(), null);
}

Note that the Debug Log is longer than just one line (you can see it by clicking on said line).
You can try to use Debug.ClearDeveloperConsole() and see what you get.