c# - 从 DispatchQueue.MainQueue.DispatchAsync 返回值

Question

我们有一个返回NSAttributedString的函数我们想要在主线程上实例化 attributeString像这样:

DispatchQueue.MainQueue.DispatchAsync(() =>
                {
                    NSAttributedString attributedString = new NSAttributedString(myHtmlData, options, out dict, ref error);
                });

如何在异步调度完成后返回属性字符串

Answer 1

您可以使用以下代码片段

var attributedString= await GetAttributedStringAsync();

        public Task<NSAttributedString> GetAttributedStringAsync()
        {
            var tcs = new TaskCompletionSource<NSAttributedString>();
            DispatchQueue.MainQueue.DispatchAsync(() =>
            {
                tcs.SetResult(new NSAttributedString(myHtmlData, options, out dict, ref error););
            });

            return tcs.Task;
        }