I'm trying to do a spell check of the Russian language in WinFormApp when entering a text field, but nothing comes out, tell me how to get out of the situation, what are your ideas? What is missing, maybe a dictionary, how to connect it and where is it stored?
public void richTextBox1_TextChanged(object sender, EventArgs e)
{
System.Windows.Forms.Integration.ElementHost elementHost1 = new System.Windows.Forms.Integration.ElementHost();
System.Windows.Controls.TextBox richTextBox1 = new System.Windows.Controls.TextBox();
richTextBox1.SpellCheck.IsEnabled = true;
richTextBox1.Language = XmlLanguage.GetLanguage("ru-RU");
elementHost1.Child = richTextBox1;
}
I am using a Barcode reader to get bar code from products .
i get the code in a textfield . and i put textchanged event on that textbox .
but the problem is that when bar code puts it value ( for example if bar code is 5 digit ) then textchanged event is fired five times .
how to get ride of this thing ???
You should be able to program your Barcode reader to output a prefix character and a suffix character (one output before the scanned value and one afterwards). Let's say that you set it up to output an asterisk (*) before the scanned data value and output a carriage return (CR) afterwards. Attach a handler to the TextBox.PreviewTextInput Event and listen out for the asterisk character:
private void PreviewTextInput(object sender, TextCompositionEventArgs e)
{
if (e.Text == "*")
{
e.Handled = true;
// Data input has started
}
}
You can use this to pop up a message saying 'Scanning...', or anything else that you require. Next, attach a handler to the TextBox.KeyUp Event and listen out for the Enter key:
private void KeyUp(object sender, KeyEventArgs e)
{
if (e.Key == Key.Return)
{
string scannedValue = ScanTextBox.Text.Replace("*", string.Empty);
// Do something with scannedValue
}
}
Now the scannedValue variable should contain the scanned barcode value.
I'm working on a WPF project which includes update/delete/insert operation on many tables. For simplicity, I use a datagrid for each table. The users can operate on these tables directly. Once done, click a button, the tables in database get updated. Twoway bind is perfect in this case. Below code seems working fine.
However, one thing I do not like is: the _DBConnection is always open. It is closed until the form exists. Usually, I always open connection whenever I need to, use it, close it immediately.
So, my question is: is below code the correct way to do the twoway bind?
thanks
public partial class MainWindow : Window
{
private OleDbConnection _DBConnection;
private OleDbDataAdapter _DataAdapterAdmin;
private DataSet _DataSetAdmin;
public MainWindow()
{
InitializeComponent();
}
private void InitAdminGrid()
{
string cmd = "SELECT * FROM Admin ORDER BY LastName";
_DataAdapterAdmin = new OleDbDataAdapter(cmd, _DBConnection);
_DataSetAdmin = new DataSet();
_DataAdapterAdmin.Fill(_DataSetAdmin);
dgAdministration.BeginInit();
dgAdministration.DataContext = _DataSetAdmin.Tables[0];
dgAdministration.Items.Refresh();
dgAdministration.EndInit();
}
private void MainWindow_Loaded(object sender, RoutedEventArgs e)
{
string connectionString = clsDataAccess.GetConnectionString();
_DBConnection = new OleDbConnection(connectionString);
_DBConnection.Open();
InitAdminGrid();
}
private void btnStart_Click(object sender, RoutedEventArgs e)
{
try
{
OleDbCommandBuilder cmd = new OleDbCommandBuilder(_DataAdapterAdmin);
_DataAdapterAdmin.Update(_DataSetAdmin);
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString(), "Exception", MessageBoxButton.OK, MessageBoxImage.Error);
}
}
private void MainWindow_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
if (_DBConnection != null)
{
_DBConnection.Close();
_DBConnection.Dispose();
}
}
}
is it possible to set number of characters per row for a multiline (AcceptsReturn="True") textbox in Silverlight? Like Cols attribute of Textarea in HTML.
Not really. Normally you just set the height and width to whatever you want. Is there a particular reason why you want a certain number of characters on each line?
[EDIT]
I found some code here that splits a string into equal chunks:
Splitting a string into chunks of a certain size
Using that, I came up with the following. It works ok but needs some tweaking.
private void TextBox_KeyUp(object sender, KeyEventArgs e)
{
var text = (sender as TextBox).Text.Replace(Environment.NewLine, "").Chunk(8).ToList();
(sender as TextBox).Text = String.Join(Environment.NewLine, text.ToArray());
(sender as TextBox).SelectionStart = (sender as TextBox).Text.Length;
}
And the extension method:
public static class Extensions
{
public static IEnumerable<string> Chunk(this string str, int chunkSize)
{
for (int i = 0; i < str.Length; i += chunkSize)
yield return str.Substring(i, Math.Min(chunkSize, str.Length - i));
}
}
I admit, it is kind of tiny, but I am looking for better ways to do the following code blocks. They should be self explaining...
private void listBoxItem_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
var listBoxItem = sender as ListBoxItem;
if (listBoxItem != null)
{
var clickObject = listBoxItem.DataContext as ClickObject;
if (clickObject != null)
{
clickObject.SingleClick();
}
}
}
Another ugly one:
private void listBox_SelectionChangedA(object sender, SelectionChangedEventArgs e)
{
var lB = sender as ListBox;
if (lB != null)
StatusBoxA.Text = "Elements selected" + lB.SelectedItems.Count;
}
Yeah, I know, its not near-death-urgent. But I do NOT like the (if != null). Any magic ideas to shorten it even more :-)
Btw, I found some nice info about a similar topic: Loops on Null Items
Nice to read...
I love good, clean code but in most cases, clean & elegant doesn't mean short and smart. Code brevity is good for competitions. Changing an "if not null" statement to a foreach might seem way cooler but it's harder for everyone else working in the project to understand what you are trying to accomplish. Believe me, even you won't remember it a few months later :P. Your code is just fine as it is!
private void listBoxItem_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
var listBoxItem = sender as ListBoxItem;
if (listBoxItem == null) return;
var clickObject = listBoxItem.DataContext as ClickObject;
if (clickObject == null) return;
clickObject.SingleClick();
}
One-liner:
private void listBox_SelectionChangedA(object sender, SelectionChangedEventArgs e)
{
As<ListBox>(sender, (lB) => StatusBoxA.Text = "Elements selected" + lB.SelectedItems.Count);
}
or, nested:
private void listBoxItem_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
As<ListBoxItem>(sender, (listBoxItem) => {
As<ClickObject>(listBoxItem.DataContext,
(clickObject) => clickObject.SingleClick());
};
}
using this static generic method (T is destination type, input is object to cast, code is a delegate (or lambda expression) to execute on success:
static void As<T>(object input, Action<T> code) where T : class
{
T foo = input as T;
if (foo != null)
code(foo);
}
Since you're using known events from the .NET framework (as opposed to a third party) and from the code it looks like you're only using those methods for specific classes (i.e. ListBoxItems and ListBoxes), there are a few things you know to be true:
sender will never be null
sender will always be a ListBoxItem, or ListBox, respectively
So why use the as operator? Just cast!
Then the first snippet becomes
private void listBoxItem_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
var listBoxItem = (ListBoxItem)sender;
var clickObject = (ClickObject)listBoxItem.DataContext;
clickObject.SingleClick();
}
Note this isn't true in the general case (you wouldn't do this if you were handling all PreviewMouseDown events in that one handler for all Control types), but for event handling code like this, especially in UI code, you can be as certain as you can be of anything, that sender will not be null and sender will be of the type you expect.
Maybe I am just being pedantic but why do you need to cast the sender if you are using the event within its host containers code.
Regardless of who made the change to a list, couldn't you just give your listbox a name and use that.
<ListBox x:Name="listbox1" />
private void listBox_SelectionChangedA(object sender, SelectionChangedEventArgs e)
{
StatusBoxA.Text = "Elements selected" + listbox1.SelectedItems.Count;
}
Or you could even achieve some of this using binding with no code behind.
This is supposed to be the same as the first one, reformatted a little:
private void listBoxItem_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
ClickObject clickObject;
if (
((sender as ListBoxItem) != null) &&
((clickObject = ((ListBoxItem)sender).DataContext as ClickObject) != null)
)
{
clickObject.SingleClick();
}
}
You can add extensions methods to Form elements, which can then trigger the events:
public static void OnSelectionChanged(this ListBox b, Action<ListBox> a)
{
b.SelectedIndexChanged += (s,e) =>
{
if (s is ListBox)
a(s as ListBox);
};
}
Using the same idea as Utaal's solution, but as an extension method...
public static void As<TSource>(this object item, Action<TSource> action) where TSource : class
{
var cast = item as TSource;
if (cast != null)
action(cast);
}
private void listBoxItem_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
sender.As<ListBoxItem>(listBoxItem =>
listBoxItem.DataContext.As<ClickObject>(clickObject =>
clickObject.SingleClick()));
}