Basic syntax of unity script (4) - access to other game objects

Most scripts don't just control the GameObjects attached to them ,Unity There are many ways to access in scripts Other Game objects and game components . Can pass Property panel assign parameters To get the game object , It can also be done through Find Method to get the game object .

Specify parameters through the property panel

Declare... In the code public Type of GameObject reference , The game object parameters will be displayed in the property panel , Then you can drag the game object to be obtained to the relevant parameter position of the property panel .

public GameObject otherObject
void Update()
{
    
   Test test=otherObject.GetComponent<Test>();// obtain Test Script components 
}

Determine the hierarchical relationship of objects

The game object has a parent-child relationship in the game composition object list , In the code, you can get Transform Component to find the child or parent object

public class Find : MonoBehaviour {
    

    void Update()
    {
    
        transform.Find("Son").Translate(0, 0, 1 * Time.deltaTime, Space.Self);// Find child objects “Son”, Let it move 
        transform.parent.Translate(0,0,1*Time.deltaTime,Space.Self);// Find the parent object , Let it move 
    }
}

Get child objects in , You can go through GetComponent Method to get other components of the child object , It can also be called directly GetComponentInChildren And GetComponentInParent Method to get components on parent and child objects
for example

public class Find2 : MonoBehaviour {
    
	void Update () {
    
		transform.GetComponentInChildren<Text>().text = "123";
	}
}

You can also use scripts to cycle through all the child objects , Then do some operation on the child object

public class Find2 : MonoBehaviour {
    
	void Update()
	{
    
		foreach (Transform child in transform)// Loop through all child objects 
		{
    
			child.GetComponent<Text>().text = " white ";
		}
	}
}

Get game objects by name or tag

Unity You can use FindWithTag Methods and Find Method to get the game object ,FindWithTag Method to get the game object with the specified label ,Find Method to get the game object with the specified name .

GameObject name=GameObject.Find("Somename");
GameObject tag=GameObject.FindWithTag("Sometag");

Get the game object by passing parameters

Some event callback method parameters contain special GameObject or component information , Such as triggering the collision event Collider Components . stay OnTriggerStay Method has an collider parameter , Through this parameter, we can get the rigid body of collision .

 void OnTriggerStay(Collider other)
 {
    
  if(other.GetComponent<Rigidbody>())// If the GameObject has a rigid body component 
  {
    
    other.GetComponent<Rigidbody>().AddForcr(0,0,2);// Apply a force to the rigid body 
  }
 }

Get the game object by component name

Unity Scripts are available through FindObjectsOfType Methods and FindObjectOfType Method to find the GameObject to which a particular type of component is attached .FindObjectsOfType Method can get all game objects that mount components of the specified type
FindObjectOfType Method can get the first game object that mounts the component of the specified type

Test test=FindObjectOfType<Test>();// Get the first found Test Components 

Test[] tests=FindObjectsOfType<Test>();// Get all Test Components