Unity教程：如何实现点击按钮显示图片的交互效果

第1步添加ui button，添加ui RawImage

第2步 添加脚本：

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

public class LoadImageByString : MonoBehaviour
{
    public RawImage showImage;
    public Button loadImage;

    private string imgPath;
    private string imageStr;
    // Start is called before the first frame update

    private void Awake()
    {
        Debug.Log("醒了");
        imgPath = @"C:\Users\Administrator\Pictures\mm\pics\005953_4.jpg";
        Debug.Log(imgPath);

        imageStr = SetImageToString(imgPath);
    }

    void Start()
    {
        Debug.Log("醒了");
        imgPath = @"C:\Users\Administrator\Pictures\mm\pics\005953_4.jpg";
        Debug.Log(imgPath);

        imageStr = SetImageToString(imgPath);
        //  loadImage = gameObject.GetComponent<Button>();
        //  showImage = gameObject.GetComponent<RawImage>();

        Debug.Log("开始");
        // showImage.texture = GetTextureByString(imageStr);
        loadImage.onClick.AddListener(() =>
        {
            showImage.texture = GetTextureByString(imageStr);

        });
    }

    /// <summary>
    /// 将图片转化为字符串
    /// </summary>
    private string SetImageToString(string imgPath)
    {
        Debug.Log("将图片转化为字符串");
        FileStream fs = new FileStream(imgPath, FileMode.Open);
        byte[] imgByte = new byte[fs.Length];
        fs.Read(imgByte, 0, imgByte.Length);
        fs.Close();
        return Convert.ToBase64String(imgByte);
    }

    /// <summary>
    /// 将字符串转换为纹理
    /// </summary>
    private Texture2D GetTextureByString(string textureStr)
    {
        Debug.Log("将字符串转换为纹理");
        Texture2D tex = new Texture2D(10, 10);
        byte[] arr = Convert.FromBase64String(textureStr);
        tex.LoadImage(arr);
        tex.Apply();
        return tex;
    }

    public void onclick()
    {
        Debug.Log("按下了");

    }
}

第3步，把脚本拖拽到button，点击button，设置脚本的变量，

运行，点击button，看RawImage显示图片，至此ok。 

左边选择场景，canvas，选择button，正常情况下，onclick会关联事件函数。

但是从网上开源项目改的，就没有。