Input.mouseScrollDelta

# [Input](https://docs.unity3d.com/cn/2019.4/ScriptReference/Input.html).mouseScrollDelta

public static [Vector2](https://docs.unity3d.com/cn/2019.4/ScriptReference/Vector2.html) **mouseScrollDelta** ;

## 描述

当前的鼠标滚动增量。（只读）

[Input.mouseScrollDelta](https://docs.unity3d.com/cn/2019.4/ScriptReference/Input-mouseScrollDelta.html) 存储在 [Vector2.y](https://docs.unity3d.com/cn/2019.4/ScriptReference/Vector2-y.html) 属性中。（[Vector2.x](https://docs.unity3d.com/cn/2019.4/ScriptReference/Vector2-x.html) 值将被忽略。）[Input.mouseScrollDelta](https://docs.unity3d.com/cn/2019.4/ScriptReference/Input-mouseScrollDelta.html) 可以是正数（向上）或负数（向下）。未旋转鼠标滚轮时，该值为零。注意，PC 上一般采用带有中心滚轮的鼠标。新版 `macOS` 在触控板上通过双指上下移动来模拟中心滚动。需要根据滚动速率，调整 [mouseScrollDelta](https://docs.unity3d.com/cn/2019.4/ScriptReference/Input-mouseScrollDelta.html) 返回的值。下面的示例中，使用了 `0.1f` 的 `scale`。

注意，[mouseScrollDelta](https://docs.unity3d.com/cn/2019.4/ScriptReference/Input-mouseScrollDelta.html) 为只读。

```
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

// Input.mouseScrollDelta example
//
// Create a sphere moved by a mouse scrollwheel or two-finger
// slide on a Mac trackpad.

public class ExampleClass : MonoBehaviour
{
    private Transform sphere;
    private float scale;

void Awake()
    {
        GameObject go = GameObject.CreatePrimitive(PrimitiveType.Sphere);
        sphere = go.transform;

// create a yellow quad
        go = GameObject.CreatePrimitive(PrimitiveType.Quad);
        go.transform.Rotate(new Vector3(90.0f, 0.0f, 0.0f));
        go.transform.localScale = new Vector3(4.0f, 4.0f, 4.0f);
        go.GetComponent<Renderer>().material.color = new Color(0.75f, 0.75f, 0.0f, 0.5f);

// change the camera color and position
        Camera.main.clearFlags = CameraClearFlags.SolidColor;
        Camera.main.transform.position = new Vector3(2, 1, 5);
        Camera.main.transform.Rotate(0, -160, 0);

scale = 0.1f;
    }

void OnGUI()
    {
        Vector3 pos = sphere.position;
        pos.y += Input.mouseScrollDelta.y * scale;
        sphere.position = pos;
    }
}
```