C# 如何使用HttpClient异步&；等待发布FCM消息

我正在努力使用

HttpClient

发布FCM消息。我收到无效的标题格式异常。我可以使用

WebRequest

发布FCM消息。但我想尝试使用HttpClient作为异步并等待

请建议我哪个是最好的HttpClient或WebRequest

<div>
<br>String uri;
<br>uri = "https://fcm.googleapis.com/fcm/send";

<br>var postData = new
<br>{
    <br>to = DeviceID,
<br>data = new
{
    MessageID = enquiryid
},<br>

<br>notification = new
{
    body = enquirymessage,
    title = FromUser,
    icon = "myicon"
}<br>
};<br>

<br>var serializer = new JavaScriptSerializer();
<br>var json = serializer.Serialize(postData);<br>
<br>using (var client = new HttpClient())
<br>{
<p>client.DefaultRequestHeaders.Authorization = new    AuthenticationHeaderValue

("key", "=" + fcmDetails.SERVER_API_KEY);<br>
<p>client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue

("application/json"));
<p>client.DefaultRequestHeaders.Add("Sender: id ", "="+ fcmDetails.PROJECT_KEY);

<p>using (var r =  client.PostAsJsonAsync(new Uri(uri), json))
<br>{
    <br>string result = await r.Content.ReadAsStringAsync();
    <br>sResponseFromServer= result;

}<br>
}

字符串uri；

uri=”https://fcm.googleapis.com/fcm/send";

var postData=new

{

to=设备ID，

数据=新
{
MessageID=inquiryid
}，


通知=新
{
body=查询消息，
title=FromUser，
icon=“myicon”
}

};


var serializer=新的JavaScriptSerializer（）；

var json=serializer.Serialize（postData）


使用（var client=new HttpClient（））

{
client.DefaultRequestHeaders.Authorization=新的AuthenticationHeaderValue
（“key”，“=”+fcmDetails.SERVER\u API\u key）；

client.DefaultRequestHeaders.Accept.Add（新MediaTypeWithQualityHeaderValue
（“应用程序/json”）；
client.DefaultRequestHeaders.Add（“发送方：id”，“=”+fcmDetails.PROJECT_KEY）；
使用（var r=client.PostAsJsonAsync（新的Uri，json））

{

字符串结果=wait r.Content.ReadAsStringAsync（）；

sResponseFromServer=结果；
}

}

---

替换代码中的行

client.DefaultRequestHeaders.Add("Sender: id ", "="+ fcmDetails.PROJECT_KEY);

与

---

非常感谢。现在我在“使用（var r=await client.postasjssonasync（新Uri（Uri），json））”行中遇到了错误请求的问题。由于“var json”值的原因，不确定其是否正确。但是代码在WebRequest中运行良好。@PajaniArjunan您能将postData打印为字符串吗？看看JSON结构是否正确？@PajaniArjunan我已经添加了示例代码检查一下，如果需要更多帮助，请告诉我

client.DefaultRequestHeaders.Add("Sender", "id=" + fcmDetails.PROJECT_KEY);

Use the sample code
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("https://fcm.googleapis.com/fcm/");
client.DefaultRequestHeaders
                      .Accept
                      .Add(new MediaTypeWithQualityHeaderValue("application/json"));//ACCEPT header

client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("key", "=" + fcmDetails.SERVER_API_KEY);
                client.DefaultRequestHeaders.Add("Sender","id=" +  fcmDetails.PROJECT_KEY);
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, "relativeAddress");
                var data = new
                {
                    to = DeviceID,
                    notification = new
                    {
                        body = "This is the message",
                        title = "This is the title",
                        icon = "myicon"
                    }
                };

                var serializer = new JavaScriptSerializer();
                var json = serializer.Serialize(data);
                request.Content = new StringContent(json,
                                                    Encoding.UTF8,
                                                    "application/json");//CONTENT-TYPE header

                var data1 = client.PostAsync("send", request.Content);
                var d = data1.Result.Content.ReadAsStringAsync();