Unity调用StartCoroutine报错：无法将method group转为IEnumerator求助

Hey there! Let's break down how to fix that error and get your map loading properly. I'll go step by step so it's easy to follow as a new Unity dev.

1. Fix the "cannot convert 'method group' to 'IEnumerator'" Error #

The problem here is straightforward: when you call StartCoroutine, you need to pass it a running instance of your coroutine, not just the method name itself.

Your current line:

StartCoroutine(Map);

Change it to add parentheses (this calls the Map() method and returns the IEnumerator that StartCoroutine needs):

StartCoroutine(Map());

That should immediately fix the compilation error you're seeing.

2. Replace the Deprecated WWW Class #

Unity has phased out the old WWW API in favor of UnityWebRequest, which is more reliable and supports modern features. Let's update your coroutine to use UnityWebRequestTexture instead:

IEnumerator Map() {
    // First, fix the URL (remove all extra spaces that break the request)
    url = "https://maps.googleapis.com/maps/api/staticmap?center=Brooklyn+Bridge,New+York,NY&zoom=13&size=600x300&maptype=roadmap&markers=color:blue%7Clabel:S%7C40.702147,-74.015794&markers=color:green%7Clabel:G%7C40.711614,-74.012318&markers=color:red%7Clabel:C%7C40.718217,-73.998284&key=AIzaSyDh1_nS-l7nWOFWvt0Gg9-9dY_11qWzK_Q";

    using (UnityWebRequest www = UnityWebRequestTexture.GetTexture(url)) {
        yield return www.SendWebRequest();

        if (www.result != UnityWebRequest.Result.Success) {
            Debug.LogError(www.error); // Log any errors so you can debug
        } else {
            // Get the texture and assign it to your RawImage
            Texture2D mapTexture = DownloadHandlerTexture.GetContent(www);
            img.texture = mapTexture;
            img.SetNativeSize();
        }
    }
}

Don't forget to add the using directive for this at the top of your script:

using UnityEngine.Networking;

3. Fix URL Formatting Issues #

Your original URL had extra spaces (like api /staticmap and & markers) that would make the Google Maps API reject your request. The updated URL above removes all those spaces to ensure it's valid.

Full Updated Script #

Here's the complete fixed script with all the changes:

using System.Collections;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Networking; // Add this for UnityWebRequest

public class GoogleAPI : MonoBehaviour {
    public string url;
    public RawImage img;
    public float lon;
    public float lat;
    public int zoom = 14;
    public int mapWidth = 600;
    public int mapHeight = 620;
    LocationInfo li;
    public enum mapType { roadMap, satellite, hybrid, terrain }; // Fixed typo: "satelite" → "satellite"
    public mapType MapSelected;
    public int scale;

    IEnumerator Map() {
        // Clean, valid URL with no extra spaces
        url = "https://maps.googleapis.com/maps/api/staticmap?center=Brooklyn+Bridge,New+York,NY&zoom=13&size=600x300&maptype=roadmap&markers=color:blue%7Clabel:S%7C40.702147,-74.015794&markers=color:green%7Clabel:G%7C40.711614,-74.012318&markers=color:red%7Clabel:C%7C40.718217,-73.998284&key=AIzaSyDh1_nS-l7nWOFWvt0Gg9-9dY_11qWzK_Q";

        using (UnityWebRequest www = UnityWebRequestTexture.GetTexture(url)) {
            yield return www.SendWebRequest();

            if (www.result != UnityWebRequest.Result.Success) {
                Debug.LogError($"Failed to load map: {www.error}");
            } else {
                Texture2D mapTexture = DownloadHandlerTexture.GetContent(www);
                img.texture = mapTexture;
                img.SetNativeSize();
            }
        }
    }

    void Start() {
        img = gameObject.GetComponent<RawImage>();
        StartCoroutine(Map()); // Fixed: added parentheses
    }

    void Update() {
    }
}

A couple extra notes:

• I fixed a typo in your enum: satelite → satellite (matches Google's API parameter name)
• Added error logging so you can see if the API request fails (check the Console window in Unity)

内容的提问来源于stack exchange，提问作者user7206653