目录
一、前言
Unity中默认按钮可以提供按钮行为，按钮样式。当我们点击按钮的时候，需要播放音效，当然我们可以用一个总的管理器去播放，或者说是继承Button来扩展点击函数，但此篇是新建一个自定义的MButton，来实现一个新按钮。
二、实现
较多的实现实际参考源码就可以，我直接复制源码，在Press函数中调用了我们的音效播放：
namespace UnityEngine.UI
{
[AddComponentMenu("UI/MButton", 30)]
public class MButton : Selectable, IPointerClickHandler, IEventSystemHandler, ISubmitHandler
{
[Serializable]
public class ButtonClickedEvent : UnityEvent
{
}
[FormerlySerializedAs("onClick")]
[SerializeField]
private ButtonClickedEvent m_OnClick = new ButtonClickedEvent();
public ButtonClickedEvent onClick
{
get
{
return m_OnClick;
}
set
{
m_OnClick = value;
}
}
protected MButton()
{
}
private void Press()
{
if (IsActive() && IsInteractable())
{
UISystemProfilerApi.AddMarker("Button.onClick", this);
AudioSystem.Instance?.PlaySound_ButtonClick();
m_OnClick.Invoke();
}
}
public virtual void OnPointerClick(PointerEventData eventData)
{
if (eventData.button == PointerEventData.InputButton.Left)
{
Press();
}
}
public virtual void OnSubmit(BaseEventData eventData)
{
Press();
if (IsActive() && IsInteractable())
{
DoStateTransition(SelectionState.Pressed, instant: false);
StartCoroutine(OnFinishSubmit());
}
}
private IEnumerator OnFinishSubmit()
{
float fadeTime = base.colors.fadeDuration;
float elapsedTime = 0f;
while (elapsedTime < fadeTime)
{
elapsedTime += Time.unscaledDeltaTime;
yield return null;
}
DoStateTransition(base.currentSelectionState, instant: false);
}
}
}其次是扩展UI创建，这里可以直接复制以下代码，其中就是对按钮Text的创建，对画布的创建，设置按钮位置等。
public static class UIEditor
{
public static void PlaceUIElementRoot(GameObject element, MenuCommand menuCommand)
{
GameObject parent = menuCommand.context as GameObject;
if (parent == null || parent.GetComponentInParent<Canvas>() == null)
{
parent = GetOrCreateCanvasGameObject();
}
string uniqueName = GameObjectUtility.GetUniqueNameForSibling(parent.transform, element.name);
element.name = uniqueName;
Undo.RegisterCreatedObjectUndo(element, "Create " + element.name);
Undo.SetTransformParent(element.transform, parent.transform, "Parent " + element.name);
GameObjectUtility.SetParentAndAlign(element, parent);
if (parent != menuCommand.context) // not a context click, so center in sceneview
SetPositionVisibleinSceneView(parent.GetComponent<RectTransform>(), element.GetComponent<RectTransform>());
Selection.activeGameObject = element;
}
public static GameObject GetOrCreateCanvasGameObject()
{
GameObject selectedGo = Selection.activeGameObject;
// Try to find a gameobject that is the selected GO or one if its parents.
Canvas canvas = (selectedGo != null) ? selectedGo.GetComponentInParent<Canvas>() : null;
if (canvas != null && canvas.gameObject.activeInHierarchy)
return canvas.gameObject;
// No canvas in selection or its parents? Then use just any canvas..
canvas = Object.FindObjectOfType(typeof(Canvas)) as Canvas;
if (canvas != null && canvas.gameObject.activeInHierarchy)
return canvas.gameObject;
// No canvas in the scene at all? Then create a new one.
return CreateNewUI();
}
private static void SetPositionVisibleinSceneView(RectTransform canvasRTransform, RectTransform itemTransform)
{
// Find the best scene view
SceneView sceneView = SceneView.lastActiveSceneView;
if (sceneView == null && SceneView.sceneViews.Count > 0)
sceneView = SceneView.sceneViews[0] as SceneView;
// Couldn't find a SceneView. Don't set position.
if (sceneView == null || sceneView.camera == null)
return;
// Create world space Plane from canvas position.
Vector2 localPlanePosition;
Camera camera = sceneView.camera;
Vector3 position = Vector3.zero;
if (RectTransformUtility.ScreenPointToLocalPointInRectangle(canvasRTransform, new Vector2(camera.pixelWidth / 2, camera.pixelHeight / 2), camera, out localPlanePosition))
{
// Adjust for canvas pivot
localPlanePosition.x = localPlanePosition.x + canvasRTransform.sizeDelta.x * canvasRTransform.pivot.x;
localPlanePosition.y = localPlanePosition.y + canvasRTransform.sizeDelta.y * canvasRTransform.pivot.y;
localPlanePosition.x = Mathf.Clamp(localPlanePosition.x, 0, canvasRTransform.sizeDelta.x);
localPlanePosition.y = Mathf.Clamp(localPlanePosition.y, 0, canvasRTransform.sizeDelta.y);
// Adjust for anchoring
position.x = localPlanePosition.x - canvasRTransform.sizeDelta.x * itemTransform.anchorMin.x;
position.y = localPlanePosition.y - canvasRTransform.sizeDelta.y * itemTransform.anchorMin.y;
Vector3 minLocalPosition;
minLocalPosition.x = canvasRTransform.sizeDelta.x * (0 - canvasRTransform.pivot.x) + itemTransform.sizeDelta.x * itemTransform.pivot.x;
minLocalPosition.y = canvasRTransform.sizeDelta.y * (0 - canvasRTransform.pivot.y) + itemTransform.sizeDelta.y * itemTransform.pivot.y;
Vector3 maxLocalPosition;
maxLocalPosition.x = canvasRTransform.sizeDelta.x * (1 - canvasRTransform.pivot.x) - itemTransform.sizeDelta.x * itemTransform.pivot.x;
maxLocalPosition.y = canvasRTransform.sizeDelta.y * (1 - canvasRTransform.pivot.y) - itemTransform.sizeDelta.y * itemTransform.pivot.y;
position.x = Mathf.Clamp(position.x, minLocalPosition.x, maxLocalPosition.x);
position.y = Mathf.Clamp(position.y, minLocalPosition.y, maxLocalPosition.y);
}
itemTransform.anchoredPosition = position;
itemTransform.localRotation = Quaternion.identity;
itemTransform.localScale = Vector3.one;
}
public static GameObject CreateNewUI()
{
// Root for the UI
var root = new GameObject("Canvas");
root.layer = LayerMask.NameToLayer("UI");
Canvas canvas = root.AddComponent<Canvas>();
canvas.renderMode = RenderMode.ScreenSpaceOverlay;
root.AddComponent<CanvasScaler>();
root.AddComponent<GraphicRaycaster>();
Undo.RegisterCreatedObjectUndo(root, "Create " + root.name);
// if there is no event system add one...
CreateEventSystem(false, null);
return root;
}
public static void CreateEventSystem(bool select, GameObject parent)
{
var esys = Object.FindObjectOfType<EventSystem>();
if (esys == null)
{
var eventSystem = new GameObject("EventSystem");
GameObjectUtility.SetParentAndAlign(eventSystem, parent);
esys = eventSystem.AddComponent<EventSystem>();
eventSystem.AddComponent<StandaloneInputModule>();
Undo.RegisterCreatedObjectUndo(eventSystem, "Create " + eventSystem.name);
}
if (select && esys != null)
{
Selection.activeGameObject = esys.gameObject;
}
}
public static GameObject CreateUIElementRoot(string name, Vector2 size)
{
GameObject go = new GameObject(name);
RectTransform rect = go.AddComponent<RectTransform>();
rect.sizeDelta = size;
return go;
}
public static GameObject CreateUIElementRoot(string name, float w, float h)
{
return CreateUIElementRoot(name, new Vector2(w, h));
}
public static GameObject CreateUIText(string name, string text, GameObject parent)
{
GameObject childText = CreateUIObject(name, parent);
Text v = childText.AddComponent<Text>();
v.text = text;
v.alignment = TextAnchor.MiddleCenter;
SetDefaultTextValues(v);
RectTransform r = childText.GetComponent<RectTransform>();
r.anchorMin = Vector2.zero;
r.anchorMax = Vector2.one;
r.sizeDelta = Vector2.zero;
return childText;
}
public static GameObject CreateUIObject(string name, GameObject parent)
{
GameObject go = new GameObject(name);
go.AddComponent<RectTransform>();
SetParentAndAlign(go, parent);
return go;
}
public static void SetDefaultTextValues(Text lbl)
{
lbl.color = new Color(50f / 255f, 50f / 255f, 50f / 255f, 1f);
}
public static void SetParentAndAlign(GameObject child, GameObject parent)
{
if (parent == null)
return;
child.transform.SetParent(parent.transform, false);
SetLayerRecursively(child, parent.layer);
}
public static void SetLayerRecursively(GameObject go, int layer)
{
go.layer = layer;
Transform t = go.transform;
for (int i = 0; i < t.childCount; i++)
SetLayerRecursively(t.GetChild(i).gameObject, layer);
}
public static T findRes<T>(string name) where T : Object
{
T[] objs = Resources.FindObjectsOfTypeAll<T>();
if (objs != null && objs.Length > 0)
{
foreach (Object obj in objs)
{
if (obj.name == name)
return obj as T;
}
}
objs = AssetBundle.FindObjectsOfType<T>();
if (objs != null && objs.Length > 0)
{
foreach (Object obj in objs)
{
if (obj.name == name)
return obj as T;
}
}
return default(T);
}
[MenuItem("GameObject/UI/MButton")]
static void CreateMButton(MenuCommand menuCmd)
{
// 创建游戏对象
float w = 160f;
float h = 30f;
GameObject btnRoot = CreateUIElementRoot("MButton", w, h);
// 创建Text对象
CreateUIText("Text", "Button", btnRoot);
// 添加脚本
btnRoot.AddComponent<CanvasRenderer>();
Image img = btnRoot.AddComponent<Image>();
img.color = Color.white;
img.fillCenter = true;
img.raycastTarget = true;
img.sprite = findRes<Sprite>("UISprite");
if (img.sprite != null)
img.type = Image.Type.Sliced;
btnRoot.AddComponent<MButton>();
btnRoot.GetComponent<Selectable>().image = img;
// 放入到UI Canvas中
PlaceUIElementRoot(btnRoot, menuCmd);
}
}