GUI.tooltip

说明

鼠标当前悬停或键盘焦点所在的控件的工具提示。(只读)。

当你创建 GUI 控件时，你可以为它们传入一个工具提示。做法是将 content 参数更改为采用自定义 GUIContent 对象，而不仅仅是传入要显示的字符串。

当鼠标悬停在带有工具提示的控件上时，它会将全局 GUI.tooltip 的值设置为传入的工具提示。如果鼠标没有悬停在任何控件上，则值将设置为具有键盘焦点的控件。在 OnGUI 代码的末尾，你可以创建一个标签，显示 GUI.tooltip 的值。


游戏视图中的 GUI 工具提示会在鼠标悬停在按钮上时出现。

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour
{
    void OnGUI()
    {
        // Make a button using a custom GUIContent parameter to pass in the tooltip.
        GUI.Button(new Rect(10, 10, 100, 20), new GUIContent("Click me", "This is the tooltip"));

        // Display the tooltip from the element that has mouseover or keyboard focus
        GUI.Label(new Rect(10, 40, 100, 40), GUI.tooltip);
    }
}

你可以使用元素的排序来创建“分层”工具提示

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour
{
    void OnGUI()
    {
        // This box is larger than many elements following it, and it has a tooltip.
        GUI.Box(new Rect(5, 35, 110, 75), new GUIContent("Box", "this box has a tooltip"));

        // This button is inside the box, but has no tooltip so it does not
        // override the box's tooltip.
        GUI.Button(new Rect(10, 55, 100, 20), "No tooltip here");

        // This button is inside the box, and HAS a tooltip so it overrides
        // the tooltip from the box.
        GUI.Button(new Rect(10, 80, 100, 20), new GUIContent("I have a tooltip", "The button overrides the box"));

        // finally, display the tooltip from the element that has
        // mouseover or keyboard focus
        GUI.Label(new Rect(10, 40, 100, 40), GUI.tooltip);
    }
}

工具提示还可以用于实现 OnMouseOver / OnMouseOut 消息传递系统

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour
{
    public string lastTooltip = " ";

    void OnGUI()
    {
        GUILayout.Button(new GUIContent("Play Game", "Button1"));
        GUILayout.Button(new GUIContent("Quit", "Button2"));

        if (Event.current.type == EventType.Repaint && GUI.tooltip != lastTooltip)
        {
            if (lastTooltip != "")
            {
                SendMessage(lastTooltip + "OnMouseOut", SendMessageOptions.DontRequireReceiver);
            }

            if (GUI.tooltip != "")
            {
                SendMessage(GUI.tooltip + "OnMouseOver", SendMessageOptions.DontRequireReceiver);
            }

            lastTooltip = GUI.tooltip;
        }
    }

    void Button1OnMouseOver()
    {
        Debug.Log("Play game got focus");
    }

    void Button2OnMouseOut()
    {
        Debug.Log("Quit lost focus");
    }
}