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So i'm not really sure why this is happening but I'm running through some DataRows where I have the control name, property, and value that I want to set. Everything works fine except when I set the TEXT property of a button. For some reason, the click event is called...
Here's some of the code I've got:
string controlName, value, property;
Control currentControl = null;
System.Reflection.PropertyInfo propertyInfo = null;
// run through all rows in the table and set the property
foreach (DataRow r in languageDataset.Tables[_parentForm.Name].Rows)
{
controlName = r["ControlName"].ToString().ToUpper();
value = r["Value"].ToString();
property = r["Property"].ToString();
// check all controls on the form
foreach (Control c in formControls)
{
// only change it if its the right control
if (c.Name.ToUpper() == controlName)
{
propertyInfo = c.GetType().GetProperty(property);
if (propertyInfo != null)
propertyInfo.SetValue(c, value, null); ******Calls Event Handler?!?!******
//
currentControl = c;
break;
}
}
}
So why in the world would it call the event handler when setting the value? Here's what I'm setting it with that's causing this:
<SnappletChangePassword>
<ControlName>buttonAcceptPassword</ControlName>
<Property>Text</Property>
<Value>Accept</Value>
</SnappletChangePassword>
I can't reproduce this with a simple short but complete program:
using System;
using System.Drawing;
using System.Reflection;
using System.Windows.Forms;
class Test
{
static void Main()
{
Button goButton = new Button {
Text = "Go!",
Location = new Point(5, 5)
};
Button targetButton = new Button {
Text = "Target",
Location = new Point(5, 50)
};
goButton.Click += (sender, args) => SetProperty(targetButton, "Text", "Changed");
targetButton.Click += (sender, args) => MessageBox.Show("Target clicked!");
Form f = new Form { Width = 200, Height = 120,
Controls = { goButton, targetButton }
};
Application.Run(f);
}
private static void SetProperty(object target, string propertyName, object value)
{
PropertyInfo property = target.GetType().GetProperty(propertyName);
property.SetValue(target, value, null);
}
}
Can you come up with a similarly complete program which does demonstrate it?
Sadly, no I couldn't reproduce it either. I'm not sure what was causing it but all I did to fix it was delete the button and put it back on there.
not sure what it was, but thanks for the code.
You didn't write that in .Net2.0 did you?
Related
Problem:
I have a Winform application with a form en on this form i have a databound DataGridView.
The datagridview is updated from the backend by updating the bind object continuesly using a timer to get the data every 10 seconds. In order to update the gui with this new data i call a RefreshDatabindings. (if i do not do this, the gui is nog updated, i am binding to a BindingList and the object implement the INotifyPropertyChanged)
When the form is big enough to show the whole datagridview at once everything is working wel. But when the form is not big enough to show the hole datagridview a scrollbar appears.
When i scroll to the right to see the rest of the datagridview i see the gui flickering (only the part that wasn't visible before scrolling). When i strech the form to make de gridview fitting again, everything is working wel (no flashing and flickering). the flickering only happens when i have to scroll.
I am lost, can please somebody help me :)?
I allready tryed the DoubleBuffered = true.
Thanks in advance!
BindingList<InstanceTableViewModel> viewModelList;
public Form1()
{
InitializeComponent();
DoubleBuffered = true;
functionParamList = new List<FunctionParameter>();
functionParamList.Add(new FunctionParameter { DeviceValue = 100, InstanceId = "1", Name = "A" });
functionParamList.Add(new FunctionParameter { DeviceValue = 200, InstanceId = "2", Name = "B" });
functionParamList.Add(new FunctionParameter { DeviceValue = 300, InstanceId = "3", Name = "C" });
viewModelList = CreateInstanceTableViewModelList();
dataGridView1.DataSource = viewModelList;
//Create timer
updateDataTimer = new System.Timers.Timer();
updateDataTimer.Interval = 500;
updateDataTimer.Elapsed += updateDataTimer_Elapsed;
updateDataTimer.Start();
}
private void updateDataTimer_Elapsed(object sender, ElapsedEventArgs e)
{
ThreadPool.QueueUserWorkItem(ReadDataThreadPoolMethod);
}
private void ReadDataThreadPoolMethod(object state)
{
Random random = new Random();
int randomNumber = random.Next(0, 100);
foreach (FunctionParameter param in functionParamList)
{
param.DeviceValue = Convert.ToInt64(randomNumber);
}
}
void functionParameter_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
var functionParameter = sender as FunctionParameter;
var propertyName = e.PropertyName;
var propertyValue = functionParameter.DeviceValue;
var parameterName = functionParameter.Name;
UpdateViewModel(functionParameter.InstanceId, propertyName, propertyValue, parameterName);
}
private void UpdateViewModel(string instanceId, string propertyName, long propertyValue, string parameterName)
{
var instanceViewModel = viewModelList.Single(x => x.InstanceId == instanceId && x.NameLabel == parameterName);
if (instanceViewModel != null)
{
instanceViewModel.ValueHex = Convert.ToUInt16(propertyValue);
}
ResetBindingsSource();
}
delegate void UpdateBindingsInvoker();
public void ResetBindingsSource()
{
if (!this.IsDisposed)
{
if (this.InvokeRequired)
{
this.Invoke(new UpdateBindingsInvoker(UpdateDataGrid));
}
else
{
UpdateDataGrid();
}
}
}
private void UpdateDataGrid()
{
dataGridView1.Refresh();
}
So here my solution:
You only uses the Forms DoubleBuffering, but the following code is an extension method to the DataGridview and successfully works (at my tests ;)
public static void DoubleBuffered(this DataGridView dgv, bool setting)
{
Type dgvType = dgv.GetType();
PropertyInfo pi = dgvType.GetProperty("DoubleBuffered",
BindingFlags.Instance | BindingFlags.NonPublic);
pi.SetValue(dgv, setting, null);
}
I found this code right here at Codeprojct.
You can use it in this way:
YourDataGridView.DoubleBuffered(true);
I hope i could help you ^^
I added a Line with C# code to my canvas, along with a context menu and attached event. I would like to rotate the Line using a context menu choice, not the menu text in the context menu:
newMenuItem1.PreviewMouseDown += new MouseButtonEventHandler((sx, ex) => {
MenuItem menuItem = (MenuItem)sx;
string theHeader = menuItem.Header.ToString();
if (theHeader.Contains("90")) {
Line ow = ex.Source as Line;
rt = new RotateTransform(90, 25, 50);
ow.RenderTransform = rt;
}
});
This code produces a null reference exception. If I substitute:
UIElement ow = ex.Source as UIElement;
The actual menu text will rotate!
Edit:
Here is more code, I am now trying originalsource too:
private void button1_Click(object sender, RoutedEventArgs e)
{
Line g = new Line();
g.Stroke = System.Windows.Media.Brushes.LawnGreen;
g.X1 = 0; g.X2 = 100;g.Y1 = 0;g.Y2 = 0;
g.HorizontalAlignment = HorizontalAlignment.Left;
g.VerticalAlignment = VerticalAlignment.Center;
g.StrokeThickness = 6;
ContextMenu k = new ContextMenu();
g.ContextMenu = k;
MenuItem newMenuItem1 = new MenuItem();
MenuItem newMenuItem2 = new MenuItem();
MenuItem newMenuItem3 = new MenuItem();
newMenuItem1.Header = "Rotate 90";
newMenuItem2.Header = "Rotate 180";
newMenuItem3.Header = "Rotate 270";
newMenuItem1.PreviewMouseDown += new MouseButtonEventHandler((sx, ex) => {
MenuItem menuItem = (MenuItem)sx;
string theHeader = menuItem.Header.ToString();
if (theHeader.Contains("90")) {
Line ow = (Line)ex.OriginalSource;
rt = new RotateTransform(90, 25, 50);
ow.RenderTransform = rt;
}
});
g.ContextMenu.Items.Add(newMenuItem1);
g.ContextMenu.Items.Add(newMenuItem2);
g.ContextMenu.Items.Add(newMenuItem3);
Canvas.SetTop(g, 18);
Canvas.SetLeft(g, 18);
MyCanvas.Children.Add(g);
///////
I also tried:
private static T FindAncestor<T>(DependencyObject current)
where T : DependencyObject
{
do
{
if (current is T)
{
return (T)current;
}
current = VisualTreeHelper.GetParent(current);
}
while (current != null);
return null;
}
but it does not work. My next plan is to get coordinates off the canvas, and try to determine what control sits there. This will become tricky though if an object is transformed, because I believe the UI sees it at the original position. I've experimented with other controls as well, like the TextBox and get similar issues.
A really quick and dirty way to do this would be to add your line to the menu item's tag property and retrieve it in the PreviewMouseDown handler
When creating your context menu:
newMenuItem1.Tag = g;
In you handler:
Line ow = ((FrameworkElement)ex.Source).Tag as Line;
The less quick and dirty way to do this would be to use the ContextMenuOpening event on your line as that should be sent with the sender equal to the control itself. You could then store a reference to the line somewhere and retrieve it again in the menu item click event. This works better when you have multiple lines (which I'm guess is what you intend) and just one context menu (instead of producing a bunch of copies of the same menu as you are doing now).
I have a window(say main window) with a frame which has a page in it. A button on the page opens another window(say popup window). Now i am trying to invoke a method in the main window from a button on the popup window. The method has to be multi-threaded, i had a similar solution running in windows forms but i keep getting the calling thread must be STA because many UI components require this in WPF.
The method on the page which opens the popup window modally
Scripts showStocks = new Scripts();
showStocks.ShowInTaskbar = false;
showStocks.ShowDialog();
if (showStocks.DialogResult==true)
{
Window1 wd1 = new Window1();
wd1.doneDeal();
}
Here window1 is our main window. The doneDeal method is
public void doneDeal()
{
// **Some Code**
BackgroundWorker wworks1 = new BackgroundWorker();
wworks1.DoWork += Tickes;
wworks1.RunWorkerCompleted += Tickes2;
wworks1.RunWorkerAsync();
// Page1 pg1 = frame1.Content as Page1;
//NextPrimeDelegate dd=new NextPrimeDelegate(okreport);
// pg1.addScriptBtn.Dispatcher.BeginInvoke(DispatcherPriority.Normal,
// new NextPrimeDelegate(okreport));
//startStopButton.Dispatcher.BeginInvoke(
// DispatcherPriority.Normal,
// new NextPrimeDelegate(CheckNextNumber));
//new Thread(() => Tick(stock, rowID, exchange)) { IsBackground = false }.Start();
}
Finally the method that i am trying to run in the background
public void Tickes(object sender, DoWorkEventArgs e)
{
}
Also i want to populate a gridview from the result of the tickes method, this will be looping and running over and over in the background but periodically returning data to be added to the grid. SHould i do that in the progress update event ? Have tried a lot to wrap my head around the dispatcher and background worker in wpf but am failing to understand the STA apartment state bit. If someone can help me to get my tickes method going or point me in the right direction, i would be very very thankful.
Well i finally was able to solve the STA thread problem am posting the answer just in case somebody comes across a similar problem in the future.
public void doneDeal()
{
if (StockData.flag == 1)
{
row1 = table.NewRow();
row1[col1] = "";
row1[col2] = "";
row1[col3] = "";
row1[col4] = "";
row1[col5] = "";
row1[col6] = "";
row1[col7] = "";
row1[col8] = "";
row1[col9] = "";
row1[col10] = "";
row1[col11] = "";
row1[col12] = "";
table.Rows.Add(row1);
string stock = StockData.stock;
int rowID = (table.Rows.Count - 1);
string exchange = StockData.exchange;
Thread bh = new Thread(delegate()
{
Tick7(stock, rowID, exchange);
});
bh.SetApartmentState(ApartmentState.STA);
bh.IsBackground = true;
bh.Start();
StockData.flag = -1;
}
}
The Tick7 method which is being called is declared like this
[STAThread]
public void Tick7(string stock, int rowID, string exchange)
{
int rowNum = rowID;
int counter = -1;
deletecounter = StockData.deletecounter;
Thread.CurrentThread.Name = StockData.stock;
.
.
.
}
When the user tabs into a CheckBox to give it focus, a dotted border appears around the CheckBox to indicate that it has focus.
When the CheckBox gets focused by code calling myCheckBox.Focus(), no such indicator appears (even though pressing the space bar toggles the state).
How can I make the CheckBox focus border appear when I have programmatically focused the CheckBox?
The border is intentionally only shown if you are navigating by the keyboard (Tab key). The MSDN page on this topic has further details:
Focus visual styles act only when the
focus action was initiated by the
keyboard. Any mouse action or
programmatic focus change disables the
mode for focus visual styles.
If you want to show a border, you could use a Trigger on the IsFocused- Property to do some visual changes (although you can't set the border with this) or if you actually want a border, you would have to create your own ControlTemplate.
There is also a thread here on SO on a somewhat related topic where the suggestion is to simulate a key press, but I would suggest not to use this solution for your problem.
By editing the KeyboardNavigationEx file from ControlzEx I managed to solve the issue (full credit goes, as always, to punker76).
Just call the KeyboardHelper.Focus method passing the UIElement that shoud be focused (e.g. KeyboardHelper.Focus(myCheckBox))
Here's the KeyboardHelper class:
public sealed class KeyboardHelper
{
private static KeyboardHelper _Instance;
private readonly PropertyInfo _AlwaysShowFocusVisual;
private readonly MethodInfo _ShowFocusVisual;
// Explicit static constructor to tell C# compiler
// not to mark type as beforefieldinit
static KeyboardHelper()
{
}
private KeyboardHelper()
{
var type = typeof(KeyboardNavigation);
_AlwaysShowFocusVisual = type.GetProperty("AlwaysShowFocusVisual", BindingFlags.NonPublic | BindingFlags.Static);
_ShowFocusVisual = type.GetMethod("ShowFocusVisual", BindingFlags.NonPublic | BindingFlags.Static);
}
internal static KeyboardHelper Instance => _Instance ?? (_Instance = new KeyboardHelper());
internal void ShowFocusVisualInternal()
{
_ShowFocusVisual.Invoke(null, null);
}
internal bool AlwaysShowFocusVisualInternal
{
get { return (bool)_AlwaysShowFocusVisual.GetValue(null, null); }
set { _AlwaysShowFocusVisual.SetValue(null, value, null); }
}
public static void Focus(UIElement element)
{
element?.Dispatcher.BeginInvoke(DispatcherPriority.Background, new Action(() =>
{
var keybHack = KeyboardHelper.Instance;
var oldValue = keybHack.AlwaysShowFocusVisualInternal;
keybHack.AlwaysShowFocusVisualInternal = true;
try
{
Keyboard.Focus(element);
keybHack.ShowFocusVisualInternal();
}
finally
{
keybHack.AlwaysShowFocusVisualInternal = oldValue;
}
}));
}
}
'initially set chkCheckBox.Appearance = 1
'on Got Focus set appearance = 0 - Flat
Private Sub chkCheckBox_GotFocus()
chkCheckBox.Appearance = 0
End Sub
'on Lost Focus set appearance = 1 - 3D
Private Sub chkCheckBox_LostFocus()
chkCheckBox.Appearance = 1
End Sub
Are there any known issues when databinding to a control's visible property?
The control is always NOT visible regardless of what my property is.
Public ReadOnly Property IsRibbonCategory() As Boolean
Get
Return True
End Get
End Property
I tried the control's text property and other properties and they seem to work correctly.
I am trying to set a Panel's visible property.
I've found that life is better if you assume that binding to a control's Visible property is broken, despite the fact that it sometimes works. See http://support.microsoft.com/kb/327305, which says as much (and while the KB article applies to .NET 1.0 and 1.1, it still seems to be a problem in at least 2.0).
I created a utility class for creating bindings which, among other things, gave me a centralized place to add a work-around. Instead of actually creating a binding on Visible it does two things:
It subscribes to the data source's INotifyPropertyChanged.PropertyChanged event and sets the Visible value as appropriate when the event is raised.
It sets the initial value of Visible according to the current data source value.
This required a little reflection code, but wasn't too bad. It is critical that you don't bind the Visible property and do the work-around or it won't work.
Workaround: Set the Visible property on the BindingComplete event.
I had same issue setting a label's Visible property - always stays false, even though setting the Enabled property works fine.
I just hit this issue in .NET 4.7.1 and Visual Studio 2017. To fix it, I changed the Visible property on my control to be initially set to True, as I had it as False previously.
Things to check:
Be sure you've instantiated the class that has the IsRibbonCategory property
Did you set the datasource of property of the binding source to the instance of the class
The datasource update mode should be on "on validation"
Make sure you didn't set the visible property manually to false on the control
Hope that helps. Can you post more code?
A workaround would be to use a Component to databind to a control's visiblity property instead of directly binding to the control's visibility property.
See below code:
using System;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;
namespace WindowsFormsApplication2
{
public class ControlVisibilityBinding : Component
{
private static readonly object EventControlChanged = new object();
private static readonly object EventVisibleChanged = new object();
private System.Windows.Forms.Control _control;
private bool _visible = true;
public event EventHandler VisibleChanged
{
add { Events.AddHandler(EventVisibleChanged, value); }
remove { Events.RemoveHandler(EventVisibleChanged, value); }
}
public event EventHandler ControlChanged
{
add { Events.AddHandler(EventControlChanged, value); }
remove { Events.RemoveHandler(EventControlChanged, value); }
}
public ControlVisibilityBinding()
{
}
public ControlVisibilityBinding(IContainer container)
{
container.Add(this);
}
[DefaultValue(null)]
public System.Windows.Forms.Control Control
{
get { return _control; }
set
{
if(_control == value)
{
return;
}
WireControl(_control, false);
_control = value;
if(_control != null)
{
_control.Visible = _visible;
}
WireControl(_control, true);
OnControlChanged(EventArgs.Empty);
OnVisibleChanged(EventArgs.Empty);
}
}
[DefaultValue(true)]
public bool Visible
{
get { return _visible; }
set
{
if(_visible != value)
{
_visible = value;
}
if(Control != null)
{
Control.Visible = _visible;
}
OnVisibleChanged(EventArgs.Empty);
}
}
private void WireControl(Control control, bool subscribe)
{
if(control == null)
{
return;
}
if(subscribe)
{
control.VisibleChanged += Control_VisibleChanged;
}
else
{
control.VisibleChanged -= Control_VisibleChanged;
}
}
private void Control_VisibleChanged(object sender, EventArgs e)
{
OnVisibleChanged(EventArgs.Empty);
}
protected virtual void OnVisibleChanged(EventArgs e)
{
EventHandler subscribers = (EventHandler)Events[EventVisibleChanged];
if(subscribers != null)
{
subscribers(this, e);
}
}
protected virtual void OnControlChanged(EventArgs e)
{
EventHandler subscribers = (EventHandler)Events[EventControlChanged];
if(subscribers != null)
{
subscribers(this, e);
}
}
}
static class Program
{
[STAThread]
static void Main()
{
using(Form form = new Form())
using(FlowLayoutPanel groupBoxLayoutPanel = new FlowLayoutPanel())
using(RadioButton visibleButton = new RadioButton())
using(RadioButton hiddenButton = new RadioButton())
using(GroupBox groupBox = new GroupBox())
using(Label text = new Label())
using(ControlVisibilityBinding visibilityBinding = new ControlVisibilityBinding())
using(TextBox inputTextBox = new TextBox())
{
groupBoxLayoutPanel.Dock = DockStyle.Fill;
groupBoxLayoutPanel.FlowDirection = FlowDirection.LeftToRight;
groupBoxLayoutPanel.AutoSize = true;
groupBoxLayoutPanel.AutoSizeMode = AutoSizeMode.GrowAndShrink;
visibleButton.Text = "Show Label";
visibleButton.AutoSize = true;
hiddenButton.Text = "Hide Label";
hiddenButton.AutoSize = true;
groupBoxLayoutPanel.Controls.Add(visibleButton);
groupBoxLayoutPanel.Controls.Add(hiddenButton);
inputTextBox.Text = "Enter Label Text Here";
inputTextBox.Dock = DockStyle.Top;
groupBox.AutoSize = true;
groupBox.AutoSizeMode = AutoSizeMode.GrowAndShrink;
groupBox.Controls.Add(groupBoxLayoutPanel);
groupBox.Dock = DockStyle.Fill;
text.AutoSize = true;
text.ForeColor = Color.Red;
text.Dock = DockStyle.Bottom;
text.BorderStyle = BorderStyle.FixedSingle;
text.Font = new Font(text.Font.FontFamily, text.Font.Size * 1.25f, FontStyle.Bold | FontStyle.Italic);
text.DataBindings.Add("Text", inputTextBox, "Text", true, DataSourceUpdateMode.Never);
visibilityBinding.Control = text;
visibleButton.DataBindings.Add("Checked", visibilityBinding, "Visible", true, DataSourceUpdateMode.OnPropertyChanged);
Binding binding = hiddenButton.DataBindings.Add("Checked", visibilityBinding, "Visible", true, DataSourceUpdateMode.OnPropertyChanged);
ConvertEventHandler invertConverter = (sender, e) => e.Value = !((bool)e.Value);
binding.Format += invertConverter;
binding.Parse += invertConverter;
form.Controls.Add(inputTextBox);
form.Controls.Add(text);
form.Controls.Add(groupBox);
Application.Run(form);
}
}
}
}
Here is my turn around, it may be stupid but it worked many times.
I put one Panel control in my form, I make it to Fill my form and I put everything in that Panel. All the controls I bind the Visible property see their visibility change according to the objects in my DataGridView.