Question

我正在尝试从android应用向我的远程服务器发出一些POST请求。我在Kotlin上使用Volley发送JSON数据并接收JSON数据。从日志中，我可以看到我正在接收JSON数据，但是我的主要功能是从请求完成返回。这就是为什么它返回null而不是结果的原因。如何使此功能等待响应？

var result : String? = null
val url = "MY-API-URL"
val post_data = JSONObject()
post_data.put("email_adress", email_adress)
post_data.put("password", password)

val que = Volley.newRequestQueue(this.mContext)
val req = JsonObjectRequest(Request.Method.POST,url,post_data,
    Response.Listener
    {
        response -> result = response.toString()
        Log.d("DebugMessageTag", "Real result from server : $result")
        // Function does not wait for request to finish.
        // It's asynchronous thread, i'll change it to synchronous and fix it. But how???
    },
    Response.ErrorListener
    {
        error: VolleyError -> result = "Error $error.message"
    }
)
que.add(req)

return result.toString()
// This is returning too early... Thats why it is still null.

Answer 1

您必须从响应块中返回。根据您当前的代码，它不会等到收到响应后再尝试对您的代码进行以下更改：

var result : String? = null
val url = "MY-API-URL"
val post_data = JSONObject()
post_data.put("email_adress", email_adress)
post_data.put("password", password)

val que = Volley.newRequestQueue(this.mContext)
val req = JsonObjectRequest(Request.Method.POST,url,post_data,
    Response.Listener
    {
        response -> result = response.toString()
        Log.d("DebugMessageTag", "Real result from server : $result")
        return result.toString()
        // Function does not wait for request to finish.
        // It's asynchronous thread, i'll change it to synchronous and fix it. But how???
    },
    Response.ErrorListener
    {
        error: VolleyError -> result = "Error $error.message"
        return result.toString()
    }
)
que.add(req)

如何等待排球请求完成

1 个答案: