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Unity C# Cheat Sheet
// Unity C# Cheat Sheet
// I made these examples for students with prior exerience working with C# and Unity.
// Too much? Try Unity's very good tutorials to get up to speed: https://unity3d.com/learn/tutorials/topics/scripting
// Various audio examples for Unity
using UnityEngine;
using System.Collections;
public class AudioExamples : MonoBehaviour
{
// Important: You need to have an AudioSource component attached to this gameObject
private AudioSource audioSource;
// Set an audioclip in the Inspector
public AudioClip clip1;
void Start()
{
// Get the AudioSource component
audioSource = GetComponent<AudioSource>();
// Plays the AudioClip set in the AudioSource component. Will be interrupted if the function is called again.
audioSource.Play();
}
void Update()
{
// AudioSource.Play() can also be paused or stopped.
// Check if audioSource is playing a clip. Jump is space and Fire1 is left ctrl.
if (audioSource.isPlaying)
{
if (Input.GetButtonDown("Jump"))
{
audioSource.Pause();
}
else if (Input.GetButtonDown("Fire1"))
{
audioSource.Stop();
}
}
// PlayOneShot can be used to play a short clip. Will not be interrupted if the function is called again.
// Can't be used with Pause & Stop. Fire2 is left alt in the Input Manager.
if (Input.GetButtonDown("Fire2"))
{
audioSource.PlayOneShot(clip1);
// You can give this an optional volume setting as well (0-1 range)
//audioSource.PlayOneShot(clip1, 0.5f);
}
// Fire3 is left shift
if (Input.GetButtonDown("Fire3"))
{
// Set the pitch and volume of the clips played by Audio Source. Volume range is 0~1
audioSource.pitch = Random.Range(0.25f, 2f);
audioSource.volume = Random.Range(0.25f, 1f);
}
}
}
// Various 2D collision examples
using UnityEngine;
using System.Collections;
public class Collision2DExamples : MonoBehaviour
{
// Collisions/Triggers require a collider component on both gameObjects and a rigidbody on at least one.
// Collision = physics. Trigger = overlap.
void OnCollisionEnter2D(Collision2D other)
{
// Do something when another collider touches this gameObject's collider
Debug.Log("Collided with something");
// Conditional statements can be used to filter collisions/triggers. Checking for a known tag is one option. Be sure to define tag in the Inspector or you will get an error.
if (other.gameObject.CompareTag("tag1"))
{
Debug.Log("tag1 collision");
}
else if (other.gameObject.CompareTag("tag2"))
{
Debug.Log("tag2 collision");
}
}
// Is Trigger needs to be selected on one of the colliders
void OnTriggerEnter2D(Collider2D other)
{
// Do something if another collider overlaps this gameObject's collider
Debug.Log("Triggered by something");
}
// Collision and Trigger also have exit and stay events
void OnCollisionExit2D(Collision2D other)
{
// Do something after a collider is no longer touching this gameObject's collider
Debug.Log("Collision ended");
}
void OnTriggerStay2D(Collider2D other)
{
// Do something while a collider is still overlapping with this gameObject's collider
Debug.Log("Still triggering");
}
}
// Various ways of enabling/disabling a gameObject's components and activating/deactivating a gameObject.
using UnityEngine;
using System.Collections;
public class EnableSetActiveExamples : MonoBehaviour
{
public GameObject targetGameObject;
private Collider2D coll2D;
void Start()
{
// SetActive can switch a gameObject on or off in the Hierarchy. Once deactivated, its components will no longer run until reactivated.
targetGameObject.SetActive(false);
// Get a collider2D component attached to this gameObject. Note: Collider2D will work with any kind of 2D collider component.
coll2D = GetComponent<Collider2D>();
// Disable or enable a component using a bool
coll2D.enabled = false;
}
// Update is called once per frame
void Update()
{
// Jump is space in Input Manager
if (Input.GetButtonDown("Jump"))
{
// Check if a gameObject is active in the scene with activeInHierarchy. Reminder: The ! is shorthand for == false. If the gameObject is inactive, activate it
if (!targetGameObject.activeInHierarchy)
{
targetGameObject.SetActive(true);
}
}
// Fire1 is left ctrl in Input Manager
if (Input.GetButtonDown("Fire1"))
{
// Check if a component is enabled. Reminder: The ! is shorthand for == false.
if (!coll2D.enabled)
{
coll2D.enabled = true;
}
}
}
}
// Various ways of finding things in Unity
using UnityEngine;
using System.Collections;
public class FindExamples : MonoBehaviour
{
// Example needs a Rigidbody2D component to work
private Rigidbody2D rb2D, otherRb2D, childRb2D;
private GameObject hierarchyObject, childObject, taggedObject;
void Start()
{
// Find a component attached to this GameObject
rb2D = GetComponent<Rigidbody2D>();
// Find a GameObject in the Hierarchy. NOTE: This will check all GameObjects in the Hierarchy! Proceed with caution...
hierarchyObject = GameObject.Find("Name Of Object");
// Find a GameObject in the hierarchy based on tag. NOTE: Fast than finding by name since it only needs to check GameObjects with the matching tag.
taggedObject = GameObject.FindWithTag("Player");
// Can be combined to find a component on a GameObject in the Hierarchy
otherRb2D = GameObject.FindWithTag("Player").GetComponent<Rigidbody2D>();
// Lowercase transform.Find can be used to search child GameObjects by name
childObject = transform.Find("Name Of Object").gameObject;
// Can also be combined
childRb2D = transform.Find("Name Of Object").GetComponent<Rigidbody2D>();
}
}
// Various IEnumerator timer examples for Unity
using UnityEngine;
using System.Collections;
public class IEnumeratorExamples : MonoBehaviour
{
// Flag for checking if a coroutine is running
private bool alreadyDelayed;
// Necessary to stop a coroutine
private IEnumerator coroutine;
void Start()
{
// Coroutines run in Start are only called once. No if statement + bool needed.
StartCoroutine(LoopingTimer(7f));
// Set to an IEnumerator
coroutine = LoopingTimer(1f);
StartCoroutine(coroutine);
}
void Update()
{
// Left ctrl key is Fire1 in Input Manager
if (Input.GetButtonDown("Fire1"))
{
StartCoroutine(DelayTimerOneShot(1f));
}
// Space bar is Jump in Input Manager
if (Input.GetButtonDown("Jump"))
{
// This if statement ensures that a coroutine can't be run again if it is already running.
if (!alreadyDelayed)
{
StartCoroutine(DelayTimerLatching(3f));
}
}
// Left alt is Fire2 in Input Manager.
if (Input.GetButtonDown("Fire2"))
{
// To stop a coroutine...
StopCoroutine(coroutine);
Debug.Log("Stopped at " + Time.time);
}
}
// Wait for an amount of time before doing something (one shot behavior)
private IEnumerator DelayTimerOneShot(float delayLength)
{
yield return new WaitForSeconds(delayLength);
// Do something
Debug.Log("Delayed One Shot");
}
// Wait for an amount of time before doing something (latching behavior)
private IEnumerator DelayTimerLatching(float delayLength)
{
// Set the already delayed flag to signal that this coroutine is already running
alreadyDelayed = true;
// Do something
Debug.Log("Delayed Latch");
yield return new WaitForSeconds(delayLength);
// Do something
Debug.Log("Delayed Latch Released");
// Reset the already delayed flag so that this coroutine can be used once again.
alreadyDelayed = false;
}
// Sequence of delays
private IEnumerator DelayTimerSequence(float delayLength1, float delayLength2)
{
alreadyDelayed = true;
yield return new WaitForSeconds(delayLength1);
// Do first thing
Debug.Log("First Delay");
yield return new WaitForSeconds(delayLength2);
// Do second thing
Debug.Log("Second Delay");
alreadyDelayed = false;
}
// This creates an endless loop
private IEnumerator LoopingTimer(float loopInterval)
{
while (true)
{
// Do something
Debug.Log("Repeat");
yield return new WaitForSeconds(loopInterval);
}
}
}
// Various examples of Input usage in Unity
using UnityEngine;
using System.Collections;
public class InputExamples : MonoBehaviour
{
// These strings need to be set in the Inspector to match Input Manager entries
public string horiAxis, vertAxis, jump, button1, button2;
public KeyCode key1;
public Vector2 speed = new Vector2(10f, 5f);
void Update()
{
// Run only once when button is pressed
if (Input.GetButtonDown(jump))
{
Debug.Log("Jump");
}
// Keep running while button is held down
if (Input.GetButton(button1))
{
Debug.Log("Fire1");
}
// Run only once when the button is released
if (Input.GetButtonUp(button2))
{
Debug.Log("Fire2");
}
// Input.GetAxis will return a number between -1 and 1, with smoothing applied (adjust Sensitivity in Input Manager)
Debug.Log("Horizontal: " + Input.GetAxis(horiAxis));
// Input.GetAxisRaw will return a number between -1 and 1, without Sensitivity smoothing applied
Debug.Log("Vertical: " + Input.GetAxisRaw(vertAxis));
// This is often multiplied by a number to create movement
Debug.Log("Horizontal Modified: " + Input.GetAxis(horiAxis) * speed.x);
// Key pressed down
if (Input.GetKeyDown(KeyCode.T))
{
Debug.Log("Key T pressed");
}
// Key held down
if (Input.GetKey(KeyCode.Y))
{
Debug.Log("Key A pressed");
}
// KeyCode can also be set in the Inspector as a variable
if (Input.GetKeyUp(key1))
{
Debug.Log("Key released");
}
}
}
// Various Instantiate examples for Unity
using UnityEngine;
using System.Collections;
public class InstantiateExamples : MonoBehaviour
{
// Set the object to be cloned in the Inspector. Be sure to use a Prefab from Project NOT Scene!
public GameObject prefab;
// Set a target transform in the Inspector to clone prefab from
public Transform spawnPoint;
// Update is called once per frame
void Update()
{
// Basic cloning
if (Input.GetButtonDown("Jump"))
{
// Pass the prefab as an argument and clone it at the transform of this gameObject.
Instantiate(prefab, transform);
// Second argument could be set to different transform, if there is another place the prefab should be cloned.
//Instantiate(prefab, spawnPoint);
}
// Advanced cloning
if (Input.GetButtonDown("Fire1"))
{
// Overloaded method which can be positioned and rotated.
GameObject p = Instantiate(prefab, transform.position, Quaternion.identity) as GameObject;
// Make this clone a child of the gameObject that spawned it
p.transform.parent = transform;
// This approach allows you to further manipulate the cloned prefab in this script. Such as...
// Destroying the clone after a set amount of time
Destroy(p, 3f);
// Accessing the cloned prefab's components. Note: The prefab needs a Rigidbody2D component for the next 2 lines to work.
Rigidbody2D pRB2D = p.GetComponent<Rigidbody2D>();
pRB2D.AddForce(Vector2.up * 100f);
}
// Clone prefab at specified transform
if (Input.GetButtonDown("Fire2"))
{
GameObject p = Instantiate(prefab, spawnPoint.position, Quaternion.identity) as GameObject;
p.transform.parent = transform;
}
}
}
// Various examples of scene management for Unity 5+
using UnityEngine;
using System.Collections;
// Needed in Unity 5+
using UnityEngine.SceneManagement;
public class SceneManagementExamples : MonoBehaviour
{
// Name of new scene. Don't forget to add to build settings!
public string scene;
// Load the new scene
public void LoadScene(string newScene)
{
SceneManager.LoadScene(newScene);
}
// Reload the current scene
public void ReloadScene()
{
SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex);
}
}
// Various UI examples for Unity 5+
using UnityEngine;
using System.Collections;
// Needed fro UI in Unity 5+
using UnityEngine.UI;
public class UIExamples : MonoBehaviour
{
// Set the target UI Text in the Inspector
public Text uiText;
// Set the target UI image in Inspector. UI Image must be "filled" type
public Image uiImage;
private int uiNumber = 7;
void Update()
{
if (Input.GetButtonDown("Jump"))
{
// Basic usage
uiText.text = "HELLO";
// Fill amount is in a range from 0-1. Empty
uiImage.fillAmount = 0;
}
else if (Input.GetButtonDown("Fire1"))
{
// Numbers must be converted to strings
uiText.text = uiNumber.ToString();
// Larger ranges of number can be converted by dividing with the max value. Halfway
uiImage.fillAmount = 3.5f/uiNumber;
}
else if (Input.GetButtonDown("Fire2"))
{
// Numbers can be formatted to display a certain number of places
uiText.text = uiNumber.ToString("000");
// Full
uiImage.fillAmount = 1;
}
}
}
@moziff

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@moziff moziff commented Mar 6, 2017

this is great!

@ChrisKlingler

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@ChrisKlingler ChrisKlingler commented Mar 6, 2017

Very nice basics list

@thygrrr

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@thygrrr thygrrr commented Mar 7, 2017

[RequireComponent (typeof (AudioSource))]
instead of the comment is much more robust and cleaner.

@alex3rq

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@alex3rq alex3rq commented Mar 7, 2017

thx a lot, this is great

@bonly

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@bonly bonly commented Mar 8, 2017

nice, thx

@soulhax

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@soulhax soulhax commented Mar 9, 2017

Awesome thank you!

@DrSharky

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@DrSharky DrSharky commented Mar 9, 2017

Thanks for this.

@batbaatap

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@batbaatap batbaatap commented May 9, 2017

Thank you wow.

@mostafanastary

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@mostafanastary mostafanastary commented Jun 10, 2017

thank you man. good share.

@pruthvirajn

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@pruthvirajn pruthvirajn commented Dec 22, 2017

Thank you maga!

@Raikir-i-sh

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@Raikir-i-sh Raikir-i-sh commented Feb 5, 2019

GODLIKE !!!

@asajadi84

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@asajadi84 asajadi84 commented Jun 28, 2019

very helpful. thank you

@douchuan

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@douchuan douchuan commented Apr 28, 2020

Awesome

@PrashantUnity

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@PrashantUnity PrashantUnity commented Sep 13, 2020

Thankyou

@LublubXT

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@LublubXT LublubXT commented Nov 23, 2020

Thanks this was very helpful!

@BrendinVenter

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@BrendinVenter BrendinVenter commented May 11, 2021

This great thank you mate.

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