按住按钮时运行代码

我是 Unity 和构建游戏的新手，我使用 2 个按钮（IncreaseButton、DecreaseButton），我遇到的问题是按钮回调函数仅在用户单击按钮时调用一次，但在按住按钮时不会调用。如何让按钮在按住时重复调用？

Code

    public void IncreaseBPM()
{
    if (speed < 12) 
    {
        speed += 0.05f;
        bpmText.GetComponent<BeatTextControl> ().beats += 1;
        PlayerPrefs.SetFloat ("savedBPM", speed);
    }
}

public void DecreaseBPM()
{
    if (speed > 1.5)
    {
        speed -= 0.05f;
        bpmText.GetComponent<BeatTextControl> ().beats -= 1;
        PlayerPrefs.SetFloat ("savedBPM", speed);
    }
}

Unity's Button组件确实not内置了此功能。您必须使用以下功能推出自己的功能Image组件作为Button。实施IPointerDownHandler and IPointerUpHandler接口然后覆盖OnPointerDown and OnPointerUp功能。

When OnPointerDown被称为，使用struct存储哪个对象/体积Image被点击并且当前点击pointerId in a List。 然后您可以检查哪个Image被点击在Update功能。

If the OnPointerUp被调用，你必须检查哪个pointerId被释放然后检查是否pointerId存在于List如果有，请将其删除。

我已经着手去做这件事了。以下是您问题中的新脚本：

public class ButtonTest : MonoBehaviour
{
    // Use this for initialization
    void Start()
    {
        //Register to Button events
        ButtonDownRelease.OnButtonActionChanged += ButtonActionChange;
        Debug.Log("Registered!");
    }

    // Update is called once per frame
    void Update()
    {

    }

    //Un-Register to Button events
    void OnDisable()
    {
        ButtonDownRelease.OnButtonActionChanged -= ButtonActionChange;
    }


    //Will be called when there is a Button action
    void ButtonActionChange(ButtonAction buttonAction)
    {
        //Check for held down
        if (buttonAction == ButtonAction.DecreaseButtonDown)
        {
            Debug.Log("Decrease Button held Down!");
            DecreaseBPM();
        }

        if (buttonAction == ButtonAction.IncreaseButtonDown)
        {
            Debug.Log("Increase Button held Down!");
            IncreaseBPM();
        }

        //Check for release
        if (buttonAction == ButtonAction.DecreaseButtonUp)
        {
            Debug.Log("Decrease Button Released!");
        }

        if (buttonAction == ButtonAction.IncreaseButtonUp)
        {
            Debug.Log("Increase Button Released!");
        }
    }

    private void IncreaseBPM()
    {
        if (TempoController.GetComponent<Pendulum>().speed < 12)
        {
            TempoController.GetComponent<Pendulum>().speed += 0.05f;
        }
    }

    private void DecreaseBPM()
    {
        if (TempoController.GetComponent<Pendulum>().speed > 1.5)
        {
            TempoController.GetComponent<Pendulum>().speed -= 0.05f;
        }
    }
}

仔细读.

创建一个名为的新脚本ButtonDownRelease然后将下面的代码放入其中。附上ButtonDownRelease脚本到Canvas The Canvas这是你的父母Images/ButtonsUI 游戏对象。创建两个Images（增加和减少）。创建两个tags called increase and decrease然后把两个Images在右边tag.

Note:

您仍然可以使用Button而不是Image如果您不想使用，则可以使其工作Image成分。只需选择每个Button并将标签更改为increase and decrease，然后选择Text每个下的组件Button并更改他们的标签increase and decrease too. 您必须更改Button's Text如果您想使用，也可以使用标签Button成分用这个脚本。另外，您还必须附上ButtonDownRelease每一个Button不至于Canvas就像你必须做的那样Image成分。

Your ButtonDownRelease script:

using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;
using UnityEngine.UI;
using System.Collections.Generic;

public class ButtonDownRelease : MonoBehaviour, IPointerDownHandler, IPointerUpHandler
{
    List<ButtonInfo> buttonInfo = new List<ButtonInfo>();

    public delegate void ButtonActionChange(ButtonAction buttonAction);
    public static event ButtonActionChange OnButtonActionChanged;

    // Update is called once per frame
    void Update()
    {
        //Send Held Button Down events
        for (int i = 0; i < buttonInfo.Count; i++)
        {
            if (buttonInfo[i].buttonPresed == ButtonAction.DecreaseButtonDown)
            {
                dispatchEvent(ButtonAction.DecreaseButtonDown);
            }

            else if (buttonInfo[i].buttonPresed == ButtonAction.IncreaseButtonDown)
            {
                dispatchEvent(ButtonAction.IncreaseButtonDown);
            }
        }
    }

    void dispatchEvent(ButtonAction btAction)
    {
        if (OnButtonActionChanged != null)
        {
            OnButtonActionChanged(btAction);
        }
    }

    public void OnPointerDown(PointerEventData eventData)
    {
        //Debug.Log("Button Down!");
        ButtonInfo bInfo = new ButtonInfo();
        bInfo.uniqueId = eventData.pointerId;
        if (eventData.pointerCurrentRaycast.gameObject.CompareTag("increase"))
        {
            bInfo.buttonPresed = ButtonAction.IncreaseButtonDown;
            addButton(bInfo);
        }
        else if (eventData.pointerCurrentRaycast.gameObject.CompareTag("decrease"))
        {
            bInfo.buttonPresed = ButtonAction.DecreaseButtonDown;
            addButton(bInfo);
        }
    }

    public void OnPointerUp(PointerEventData eventData)
    {
        //Debug.Log("Button Down!" + eventData.pointerCurrentRaycast);
        removeButton(eventData.pointerId);
    }

    void addButton(ButtonInfo bInfo)
    {
        buttonInfo.Add(bInfo);
    }

    void removeButton(int unqID)
    {
        for (int i = 0; i < buttonInfo.Count; i++)
        {
            if (unqID == buttonInfo[i].uniqueId)
            {
                //Send Release Button Up events
                if (buttonInfo[i].buttonPresed == ButtonAction.DecreaseButtonDown)
                {
                    dispatchEvent(ButtonAction.DecreaseButtonUp);
                }

                else if (buttonInfo[i].buttonPresed == ButtonAction.IncreaseButtonDown)
                {
                    dispatchEvent(ButtonAction.IncreaseButtonUp);
                }
                buttonInfo.RemoveAt(i);
            }
        }

    }

    public struct ButtonInfo
    {
        public int uniqueId;
        public ButtonAction buttonPresed;
    }
}

public enum ButtonAction
{
    None,
    IncreaseButtonDown, IncreaseButtonUp,
    DecreaseButtonDown, DecreaseButtonUp
}

最后，如果你只使用，你会遇到问题boolean变量来做到这一点。这需要完成pointerId就像这个答案中提供的脚本一样，以避免移动设备上的错误。此错误的一个很好的例子是当您单击Image然后在另一个游戏对象上松开手指，您的布尔逻辑将break因为OnPointerUp不会被调用。在移动设备上使用多点触控也会引起问题。