我不能让我的服务器用SignalR流数据到客户端。流只能得到1个值,在这种情况下是0,然后落回javascript complete回调方法。需要一些帮助来弄清楚为什么不能工作。下面是Hub的代码和JS的代码。
public class ChatHub : Hub
{
private Channel<double> channel = Channel.CreateUnbounded<double>();
public async IAsyncEnumerable<double> GetData(CancellationToken cancellationToken)
{
while (await channel.Reader.WaitToReadAsync())
{
while (channel.Reader.TryRead(out var item))
{
yield return item;
}
}
}
public async Task PublishData(IAsyncEnumerable<double> data)
{
await foreach (var point in data)
{
await channel.Writer.WriteAsync(point);
}
}
}
JS:
(async () => {
const latestNumber = 0;
const connection = new signalR.HubConnectionBuilder()
.withUrl("/chatHub")
.build();
await connection.start();
connection.stream("GetData")
.subscribe({
next: (item) => {
var li = document.createElement("li");
li.textContent = item;
document.getElementById("messagesList").appendChild(li);
},
complete: () => {
var li = document.createElement("li");
li.textContent = "Stream completed";
document.getElementById("messagesList").appendChild(li);
},
error: (err) => {
var li = document.createElement("li");
li.textContent = err;
document.getElementById("messagesList").appendChild(li);
},
});
console.log(latestNumber);
})();
我找到了答案,做了一个service类singleton,把channel加进去。然后我从中心调用了单子类,所以我在服务器和客户端之间得到了相同的通道实例。