im building an WPF application in which i have a textbox, but the problem is that this textbox needs to get the contents of a file as text, only the txt file keeps getting written too.
i have made a class to handle this:
public class ChatHandler
{
public FileStream stream;
StreamWriter writer;
StreamReader reader;
public ChatHandler()
{
stream = new FileStream(@"chat/" + DateTime.Today.ToString("d") + ".txt", FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite);
writer = new StreamWriter(stream);
reader = new StreamReader(stream);
}
public void Write(string line)
{
writer.WriteLineAsync(line);
writer.Flush();
}
public string Read()
{
string tmp = "";
string line;
while((line = reader.ReadLine()) != null){
tmp += line + '\n';
}
return tmp;
}
}
and i have a user control which has the textbox:
public partial class ChatScreen : UserControl
{
MainWindow parent;
ChatHandler chatHandler;
BackgroundWorker worker;
public ChatScreen()
{
InitializeComponent();
chatHandler = new ChatHandler();
worker = new BackgroundWorker();
worker.WorkerSupportsCancellation = true;
worker.DoWork += new DoWorkEventHandler(run);
}
private void load()
{
}
private void write(string text)
{
if (chat.Text != text && text != "")
{
chat.Text = text;
}
}
private void run(object sender, DoWorkEventArgs e)
{
BackgroundWorker bg = sender as BackgroundWorker;
while (!bg.CancellationPending)
{
chat.Dispatcher.BeginInvoke((Action)(()=>{
write(parent.Handler.Read());
}));
Thread.Sleep(100);
}
}
private void chat_Loaded(object sender, RoutedEventArgs e)
{
parent = (MainWindow)Window.GetWindow(this);
if (!worker.CancellationPending)
{
worker.RunWorkerAsync();
}
}
private void chat_Unloaded(object sender, RoutedEventArgs e)
{
worker.CancelAsync();
}
}
but now the problem occurs: the text is never changed, it gets set once and is never changed at all anymore :( eventhough in the text file the lines are getting added.
the content of the xaml file are:
<UserControl x:Class="tantiBotv2.ChatScreen"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="381" d:DesignWidth="641" Loaded="chat_Loaded" Unloaded="chat_Unloaded">
<Grid Style="{StaticResource ContentRoot}">
<ScrollViewer HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Visible">
<TextBox IsReadOnly="true" Margin="0,0,0,0" TextWrapping="Wrap" Name="chat" IsReadOnlyCaretVisible="false"/>
</ScrollViewer>
</Grid>
</UserControl>
can anyone please help me with this problem?
I cannot reproduce your exact problem, the problem I get is that only new text in the text file appears. This is because the StreamReader is a member variable and it is a forward only reader. You can fix this by doing:
public string Read()
{
using (var stream = new FileStream(@"chat.txt", FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite))
{
using (var reader = new StreamReader(stream))
{
string tmp = "";
string line;
while ((line = reader.ReadLine()) != null)
{
tmp += line + '\n';
}
return tmp;
}
}
}
EDIT: After the problem was clarified a bit more:
XAML:
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition></ColumnDefinition>
<ColumnDefinition></ColumnDefinition>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="*"></RowDefinition>
</Grid.RowDefinitions>
<DockPanel Grid.Column="0" LastChildFill="True">
<Label DockPanel.Dock="Top">IRC channel simulator</Label>
<Button DockPanel.Dock="Top" Click="Button_Click">Send Chat</Button>
<ScrollViewer HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Visible">
<TextBox Background="AliceBlue" AcceptsReturn="True" Margin="0,0,0,0" TextWrapping="Wrap" Name="chatWriter" IsReadOnlyCaretVisible="false" />
</ScrollViewer>
</DockPanel>
<ScrollViewer Grid.Column="1" HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Visible">
<TextBox IsReadOnly="true" Margin="0,0,0,0" TextWrapping="Wrap" Name="chat" IsReadOnlyCaretVisible="false"/>
</ScrollViewer>
</Grid>
Code Behind Xaml:
public partial class MainWindow : Window
{
ChatHandler chatHandler;
BackgroundWorker worker;
public MainWindow()
{
InitializeComponent();
chatHandler = new ChatHandler();
worker = new BackgroundWorker();
worker.WorkerSupportsCancellation = true;
worker.DoWork += new DoWorkEventHandler(run);
}
private void write(string text)
{
if (chat.Text != text && text != "")
{
chat.Text = text;
}
}
private void run(object sender, DoWorkEventArgs e)
{
BackgroundWorker bg = sender as BackgroundWorker;
while (!bg.CancellationPending)
{
chat.Dispatcher.BeginInvoke((Action)(() => {
write(chatHandler.Read());
}));
Thread.Sleep(100);
}
}
private void chat_Loaded(object sender, RoutedEventArgs e)
{
if (!worker.CancellationPending)
{
worker.RunWorkerAsync();
}
}
private void chat_Unloaded(object sender, RoutedEventArgs e)
{
worker.CancelAsync();
}
private void Button_Click(object sender, RoutedEventArgs e)
{
chatHandler.Write(chatWriter.Text);
}
}
ChatHandler.cs
public class ChatHandler
{
public FileStream stream;
//StreamWriter writer;
//StreamReader reader;
public ChatHandler()
{
stream = new FileStream(@"chat.txt", FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite);
//writer = new StreamWriter(stream);
//reader = new StreamReader(stream);
}
public void Write(string line)
{
using (var fileStream = new FileStream(@"chat.txt", FileMode.Append, FileAccess.Write, FileShare.ReadWrite))
{
using (var writer = new StreamWriter(fileStream))
{
writer.WriteLineAsync(line);
writer.Flush();
}
}
}
public string Read()
{
using (var fileStream = new FileStream(@"chat/" + DateTime.Today.ToString("d") + ".txt", FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
using (var reader = new StreamReader(fileStream))
{
string tmp = "";
string line;
while ((line = reader.ReadLine()) != null)
{
tmp += line + '\n';
}
return tmp;
}
}
}
}