错误:无法将 lambda 表达式转换为类型 [英] error: cannot convert lambda expression to type
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问题描述
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.IO.Ports;
using System.Threading;
using System.Windows.Threading;
using System.Data.SQLite;
namespace SerialTrial
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public class ThreadExample
{
FlowDocument mcFlowDoc = new FlowDocument();
Paragraph para = new Paragraph();
public static void ThreadJob(MainWindow mainWindow)
{
string dBConnectionString = @"Data Source = C:\Users\Documents\Visual Studio 2012\Projects\SerialTrial\SerialTrial\bin\Debug\employee.sqlite;";
SQLiteConnection sqliteCon = new SQLiteConnection(dBConnectionString);
//open connection to database
try
{
sqliteCon.Open();
SQLiteCommand createCommand = new SQLiteCommand("Select empID from EmployeeList", sqliteCon);
SQLiteDataReader reader;
reader = createCommand.ExecuteReader();
//richtextbox2.Document.Blocks.Clear();
while (reader.Read())
{
string Text = (String.Format("{0}", Object.Equals(Variables.buffering, reader.GetValue(0))));
if (Convert.ToBoolean(Text))
{
mainWindow.Dispatcher.Invoke(() =>
mainWindow.richtextbox2.Document.Blocks.Add(new Paragraph(new Run(Text))));
string text = "s";
mainWindow.WriteSerial(text);
Console.WriteLine(Text);
//richtextbox2.Document.Blocks.Add(new Paragraph(new Run(Text)));
}
}
sqliteCon.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}
public partial class MainWindow : Window
{
SerialPort serial = new SerialPort();
//string received_data;
//Thread readThread = new Thread(Read);
FlowDocument mcFlowDoc = new FlowDocument();
Paragraph para = new Paragraph();
public MainWindow()
{
InitializeComponent();
combobox1.Items.Insert(0, "Select Port");
combobox1.SelectedIndex = 0;
string[] ports = null;
ports = SerialPort.GetPortNames();
// Display each port name to the console.
int c = ports.Count();
for (int i = 1; i <= c; i++)
{
if (!combobox1.Items.Contains(ports[i - 1]))
{
combobox1.Items.Add(ports[i - 1]);
}
}
}
string dBConnectionString = @"Data Source = C:\Users\Documents\Visual Studio 2012\Projects\SerialTrial\SerialTrial\bin\Debug\employee.sqlite;";
static int count = 0;
private void Button_Click(object sender, RoutedEventArgs e)
{
count++;
string[] ports = null;
ports = SerialPort.GetPortNames();
// Display each port name to the console.
int c = ports.Count();
for (int i = 1; i <= c; i++)
{
if (!combobox1.Items.Contains(ports[i - 1]))
{
combobox1.Items.Add(ports[i - 1]);
}
}
}
private void combobox1_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
string myItem = combobox1.SelectedItem.ToString();
textbox1.Text = myItem;
}
private void button2_Click(object sender, RoutedEventArgs e)
{
try
{
if ((string)button2.Content == "Connect")
{
string myItem = combobox1.SelectedItem.ToString();
if (myItem == "Select Port")
{
MessageBox.Show("Select Port");
}
else
{
serial.PortName = myItem;
serial.Open();
textbox2.Text = "Serial Port Opened";
button2.Content = "Disconnect";
serial.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(port_DataReceived);
}
}
else
{
serial.Close();
button2.Content = "Connect";
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
#region Receiving
public void port_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
int bytes = serial.BytesToRead;
byte[] buffer = new byte[bytes];
serial.Read(buffer, 0, bytes);
foreach (var item in buffer)
{
Console.Write(item.ToString());
}
Variables.buffering = BitConverter.ToInt64(buffer, 0);
Console.WriteLine();
Console.WriteLine(Variables.buffering);
Thread thread = new Thread(new ThreadStart(() => ThreadExample.ThreadJob(this)));
thread.Start();
thread.Join();
}
/*
private delegate void UpdateUiTextDelegate(string text);
private void Receive(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
// Collecting the characters received to our 'buffer' (string).
received_data = serial.ReadExisting();
Dispatcher.Invoke(DispatcherPriority.Send, new UpdateUiTextDelegate(WriteData), received_data);
}
private void WriteData(string text)
{
// Assign the value of the recieved_data to the RichTextBox.
para.Inlines.Add(text);
mcFlowDoc.Blocks.Add(para);
richtextbox2.Document = mcFlowDoc;
richtextbox2.ScrollToEnd();
}
*/
#endregion
private void button3_Click(object sender, RoutedEventArgs e)
{
if (serial.IsOpen)
{
TextRange allTextRange = new TextRange(richtextbox1.Document.ContentStart, richtextbox1.Document.ContentEnd);
string allText = allTextRange.Text;
serial.WriteLine(allText);
}
}
public void WriteSerial(string text)
{
serial.Write(text);
}
}
}
嗨.我有这段代码.它位于我的主窗口代码之外.我想要的是我会根据我的需要调用我的富文本框来显示一些东西.
Hi. I have this piece of code. It is situated outside my main window code. What I want is that I will call for my richtextbox to display something based on my needs.
我对这个错误一无所知:错误 1 无法将 lambda 表达式转换为类型System.Delegate"，因为它不是委托类型我怎样才能解决这个问题?它指向具有 .Invoke 对象的那条线.
I don't know anything about this error: Error 1 Cannot convert lambda expression to type 'System.Delegate' because it is not a delegate type How can I fix this? It is pointing at that line which has an .Invoke object.
推荐答案
尝试显式添加 Action Delegate.
Try adding the Action Delegate explicitly.
代码
mainWindow.Dispatcher.Invoke(new Action(() =>
mainWindow.richtextbox2.Document.Blocks.Add(new Paragraph(new Run("Hello")))));
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