C# 如何在后台线程中运行此代码
本文关键字：运行 代码 线程 后台 | 更新日期: 2023-09-27 18:37:15
所以我已经坚持了一段时间了。（表格申请）
我希望它在"后台"运行。我通常用"搜索按钮"来称呼它。
到目前为止，我已经读到您无法在另一个线程中访问 UI 内容？那么我将如何处理这个问题并使 UI 在加载结果并将其转换为按钮时可访问呢？对于刚开始使用 C# 的人来说，有什么简单的方法可以做到这一点吗？
下面的代码：
private void Search_Video_Youtube(string page)
{
YouTubeService youtube = new YouTubeService(new BaseClientService.Initializer()
{
ApplicationName = this.GetType().ToString(),
ApiKey = "*MyApiKeyGoesHere*",
});
var listRequest = youtube.Search.List("snippet");
listRequest.Q = Youtube_SearchVideo_Box.Text;
listRequest.MaxResults = 50;
listRequest.Type = "video";
listRequest.PageToken = nextPageToken;
video_results_vids = video_results_vids + 50;
var resp = listRequest.Execute();
List<string> videos = new List<string>();
foreach (SearchResult result in resp.Items)
{
switch (result.Id.Kind)
{
case "youtube#video":
PictureBox picturebox = new PictureBox();
picturebox.Height = 100;
picturebox.Width = 100;
picturebox.BorderStyle = BorderStyle.None;
picturebox.SizeMode = PictureBoxSizeMode.StretchImage;
string template2 = "http://i3.ytimg.com/vi/{0}{1}";
string data2 = result.Id.VideoId.ToString();
string quality2 = "/default.jpg";
string messageB = string.Format(template2, data2, quality2);
var request = WebRequest.Create(messageB);
using (var response = request.GetResponse())
using (var stream = response.GetResponseStream())
{
picturebox.Image = Bitmap.FromStream(stream);
}
flowLayoutPanel1.Controls.Add(picturebox);
listnumber += 1;
Button button = new Button();
button.Text = listnumber.ToString() + " " + result.Snippet.Title.ToString();
button.Tag = result.Id.VideoId;
button.TextImageRelation = TextImageRelation.ImageBeforeText;
button.FlatStyle = FlatStyle.Flat;
button.ForeColor = Color.LightSteelBlue;
button.BackColor = Color.SteelBlue;
button.Width = (flowLayoutPanel1.Width - 150);
button.TextAlign = ContentAlignment.MiddleLeft;
button.Height = 100;
button.Font = new Font(button.Font.FontFamily, 10);
button.Click += (s, e) => {
Youtube_video_Player_hider.Visible = false;
var a = result.Id.VideoId;
string template = "https://www.youtube.com/v/{0}{1}";
string data = a.ToString();
string quality = Video_Quality;
string messagea = string.Format(template, data, quality);
axShockwaveFlash1.Movie = messagea;
axShockwaveFlash1.Play();
};
flowLayoutPanel1.Controls.Add(button);
break;
}
}
nextPageToken = resp.NextPageToken;
toolStripStatusLabel1.Text = "Status : Idle";
toolStripStatusLabel2.Text = "Results : " + video_results_vids;
}
欢迎任何帮助，但请详细解释，因为我对 C# 很陌生，但我确实有基本的编程知识。（另外，如果您看到我可以做得更好的东西，请随时指出，我在这里学习:)）
编辑：感谢Jeroen van langen（下面的答案）我想通了。当前代码现在是：
// At using Stuff
using ExtensionMethods;
private void Search_Video_Youtube(string page)
{
ThreadPool.QueueUserWorkItem(new WaitCallback((state) =>
{
YouTubeService youtube = new YouTubeService(new BaseClientService.Initializer()
{
ApplicationName = this.GetType().ToString(),
ApiKey = "ThisIsTheApiKeyYouTubeWantsForAnyoneWondering",
});
var listRequest = youtube.Search.List("snippet");
listRequest.Q = Youtube_SearchVideo_Box.Text;
listRequest.MaxResults = 50;
listRequest.Type = "video";
listRequest.PageToken = nextPageToken;
video_results_vids = video_results_vids + 50;
var resp = listRequest.Execute();
List<string> videos = new List<string>();
Parallel.ForEach(resp.Items, (SearchResult result) =>
{
switch (result.Id.Kind)
{
case "youtube#video":
string template2 = "http://i3.ytimg.com/vi/{0}{1}";
string data2 = result.Id.VideoId.ToString();
string quality2 = "/default.jpg";
string messageB = string.Format(template2, data2, quality2);
Image image;
var request = WebRequest.Create(messageB);
using (var response = request.GetResponse())
using (var stream = response.GetResponseStream())
{
image = Bitmap.FromStream(stream);
}
listnumber += 1;
this.Invoke(() =>
{
PictureBox picturebox = new PictureBox();
picturebox.Height = 100;
picturebox.Width = 100;
picturebox.Image = image;
picturebox.BorderStyle = BorderStyle.None;
picturebox.SizeMode = PictureBoxSizeMode.StretchImage;
flowLayoutPanel1.Controls.Add(picturebox);
Button button = new Button();
button.Text = listnumber.ToString() + " " + result.Snippet.Title.ToString();
button.Tag = result.Id.VideoId;
button.TextImageRelation = TextImageRelation.ImageBeforeText;
button.FlatStyle = FlatStyle.Flat;
button.ForeColor = Color.LightSteelBlue;
button.BackColor = Color.SteelBlue;
button.Width = (flowLayoutPanel1.Width - 150);
button.TextAlign = ContentAlignment.MiddleLeft;
button.Height = 100;
button.Font = new Font(button.Font.FontFamily, 10);
button.Click += (s, e) =>
{
Youtube_video_Player_hider.Visible = false;
var a = result.Id.VideoId;
string template = "https://www.youtube.com/v/{0}{1}";
string data = a.ToString();
string quality = Video_Quality;
string messagea = string.Format(template, data, quality);
axShockwaveFlash1.Movie = messagea;
axShockwaveFlash1.Play();
};
flowLayoutPanel1.Controls.Add(button);
});
break;
}
nextPageToken = resp.NextPageToken;
this.Invoke(() =>
{
toolStripStatusLabel1.Text = "Status : Idle";
toolStripStatusLabel2.Text = "Results : " + video_results_vids;
});
});
}));
}
课程内容 ：
using System;
using System.Windows.Forms;
namespace ExtensionMethods
{
public static class MyExtensions
{
public static void Invoke(this Control control, Action action)
{
control.Invoke((Delegate)action);
}
}
}
你应该在线程上执行"whole"方法。尝试将所有控件的创建移动到一个部分，并在 GUI 线程上调用该部分。最耗时的时间将是网络请求
伪：像这样：
private void Search_Video_Youtube(string page)
{
ThreadPool.QueueUserWorkItem(new WaitCallback((state) =>
{
YouTubeService youtube = new YouTubeService(new BaseClientService.Initializer()
{
ApplicationName = this.GetType().ToString(),
ApiKey = "*MyApiKeyGoesHere*",
});
var listRequest = youtube.Search.List("snippet");
listRequest.Q = Youtube_SearchVideo_Box.Text;
listRequest.MaxResults = 50;
listRequest.Type = "video";
listRequest.PageToken = nextPageToken;
video_results_vids = video_results_vids + 50;
var resp = listRequest.Execute().OfType<SearchResult>();
List<string> videos = new List<string>();
Parallel.Foreach(resp.Items, (result) =>
{
switch (result.Id.Kind)
{
case "youtube#video":
string template2 = "http://i3.ytimg.com/vi/{0}{1}";
string data2 = result.Id.VideoId.ToString();
string quality2 = "/default.jpg";
string messageB = string.Format(template2, data2, quality2);
Bitmap image;
var request = WebRequest.Create(messageB);
using (var response = request.GetResponse())
using (var stream = response.GetResponseStream())
{
image = Bitmap.FromStream(stream);
}
listnumber += 1;
this.Invoke(() =>
{
PictureBox picturebox = new PictureBox();
picturebox.Height = 100;
picturebox.Width = 100;
picturebox.Image = image;
picturebox.BorderStyle = BorderStyle.None;
picturebox.SizeMode = PictureBoxSizeMode.StretchImage;
flowLayoutPanel1.Controls.Add(picturebox);
Button button = new Button();
button.Text = listnumber.ToString() + " " + result.Snippet.Title.ToString();
button.Tag = result.Id.VideoId;
button.TextImageRelation = TextImageRelation.ImageBeforeText;
button.FlatStyle = FlatStyle.Flat;
button.ForeColor = Color.LightSteelBlue;
button.BackColor = Color.SteelBlue;
button.Width = (flowLayoutPanel1.Width - 150);
button.TextAlign = ContentAlignment.MiddleLeft;
button.Height = 100;
button.Font = new Font(button.Font.FontFamily, 10);
button.Click += (s, e) => {
Youtube_video_Player_hider.Visible = false;
var a = result.Id.VideoId;
string template = "https://www.youtube.com/v/{0}{1}";
string data = a.ToString();
string quality = Video_Quality;
string messagea = string.Format(template, data, quality);
axShockwaveFlash1.Movie = messagea;
axShockwaveFlash1.Play();
};
flowLayoutPanel1.Controls.Add(button);
});
break;
}
nextPageToken = resp.NextPageToken;
this.Invoke(() =>
{
toolStripStatusLabel1.Text = "Status : Idle";
toolStripStatusLabel2.Text = "Results : " + video_results_vids;
});
}, null);
}
创建一个接受resp类型参数的委托
public delegate void ListDispatcher(var resp)
请记住，VAR需要替换为resp的确切类型。
现在在主类中创建一个 ListDispatcher 引用成员。
public ListDispatcher dispatcher;
并将新方法添加到其调用列表中。
dispatcher += MyNewMethod;
将新方法定义为
public void MyNewMethod(var resp){
//Move all your controls creation code here
}
调用后删除代码
var resp = listRequest.Execute();
并简单地放在那里
dispatcher(resp);
现在，您可以在单独的线程中安全地调用Search_Video_Youtube(string page)。