Unity 使用资源管理器 加载文件

需求：Unity开发PC端，使用资源管理器加载本地资源。

1.调用Win32打开资源管理器对话框

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public class OpenFileDlg
{
    public int structSize = 0;
    public IntPtr dlgOwner = IntPtr.Zero;
    public IntPtr instance = IntPtr.Zero;
    public String filter = null;
    public String customFilter = null;
    public int maxCustFilter = 0;
    public int filterIndex = 0;
    public String file = null;
    public int maxFile = 0;
    public String fileTitle = null;
    public int maxFileTitle = 0;
    public String initialDir = null;
    public String title = null;
    public int flags = 0;
    public short fileOffset = 0;
    public short fileExtension = 0;
    public String defExt = null;
    public IntPtr custData = IntPtr.Zero;
    public IntPtr hook = IntPtr.Zero;
    public String templateName = null;
    public IntPtr reservedPtr = IntPtr.Zero;
    public int reservedInt = 0;
    public int flagsEx = 0;
}

public class OpenFileDialog
{
    [DllImport("Comdlg32.dll", SetLastError = true, ThrowOnUnmappableChar = true, CharSet = CharSet.Auto)]
    public static extern bool GetOpenFileName([In, Out] OpenFileDlg ofd);



}

2.通过对话框获取选择文件的路径

public void BtnTest()
    {
        OpenFileDlg pth = new OpenFileDlg();
        pth.structSize = System.Runtime.InteropServices.Marshal.SizeOf(pth);
        pth.filter = "文件(*.jpg )\0*.jpg";//筛选文件类型
        pth.initialDir = "Wen";
        pth.file = new string(new char[256]);
        pth.maxFile = pth.file.Length;
        pth.fileTitle = new string(new char[64]);
        pth.maxFileTitle = pth.fileTitle.Length;
        pth.initialDir = Application.streamingAssetsPath.Replace('/', '\\');  
        pth.title = "上传素材";     
        pth.defExt = "JPG";//显示文件类型
        pth.flags = 0x00080000 | 0x00001000 | 0x00000800 | 0x00000200 | 0x00000008;
        if (OpenFileDialog.GetOpenFileName(pth))
        {
            string filepath = pth.file;//选择的文件路径;

            DirectoryInfo i = new DirectoryInfo(filepath);

            //上级目录
            string path = i.Parent.FullName;//返回文件的上级目录
            Debug.Log(path);//文件目录父目录
            Debug.Log(i.FullName);//文件路径全
            StartCoroutine(LoadIamge(i.FullName));

        }

3.如果需要直接加载图片到UGUI上，可以协程进行加载。

IEnumerator LoadIamge(string path)
    {   //计算加载用时    
        double startTime = Time.time;

        WWW www = new WWW("file:///" + path);
        yield return www;
        if (www != null && string.IsNullOrEmpty(www.error))
        {
            //获取Texture
            Texture2D texture = www.texture;
            //根据获取的Texture创建一个sprite
            Sprite sprite = Sprite.Create(texture, new Rect(0, 0, texture.width, texture.height), new Vector2(0.5f, 0.5f));
            //将sprite显示在图片上
            //image.sprite = sprite;
            //图片设置为原始尺寸
            //image.SetNativeSize();
            loadSprite = sprite;

            //计算加载用时
            startTime = Time.time - startTime;
            Debug.Log("WWW加载用时:" + startTime);
        }
    }