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C# WPF MouseEnter and MouseLeave on Grid

I made 2 MouseEvents, they working, but the problem, that they working not like i have expected. I need these 2 events to be active when my mouse pointer is right in Grid Space, but now they working only if the pointer is on any Line.
my code:
// Grid 3 Rows.
Grid grid_Edit = new Grid();
Grid.SetRow(grid_Edit, 0);
Grid.SetColumn(grid_Edit, 1);
RowDefinition rowDef1 = new RowDefinition();
RowDefinition rowDef2 = new RowDefinition();
RowDefinition rowDef3 = new RowDefinition();
grid_Edit.RowDefinitions.Add(rowDef1);
grid_Edit.RowDefinitions.Add(rowDef2);
grid_Edit.RowDefinitions.Add(rowDef3);
grid_Edit.RowDefinitions[0].Height = new GridLength(1, GridUnitType.Star);
grid_Edit.RowDefinitions[1].Height = new GridLength(1, GridUnitType.Star);
grid_Edit.RowDefinitions[2].Height = new GridLength(1, GridUnitType.Star);
grid_Edit.MouseEnter += new MouseEventHandler(gridEdit_MouseEnter);
grid_Edit.MouseLeave += new MouseEventHandler(gridEdit_MouseLeave);
mainWindow_ref.Children.Add(grid_Edit);
// 3 lines
line1.Stroke = Brushes.White;
line1.X1 = 1;
line1.Stretch = Stretch.Fill;
Grid.SetRow(line1, 0);
line1.VerticalAlignment = VerticalAlignment.Center;
line2.Stroke = Brushes.White;
line2.X1 = 1;
line2.Stretch = Stretch.Fill;
Grid.SetRow(line2, 1);
line2.VerticalAlignment = VerticalAlignment.Center;
line3.Stroke = Brushes.White;
line3.X1 = 1;
line3.Stretch = Stretch.Fill;
Grid.SetRow(line3, 2);
line3.VerticalAlignment = VerticalAlignment.Center;
// add lines to grid_Edit
grid_Edit.Children.Add(line1);
grid_Edit.Children.Add(line2);
grid_Edit.Children.Add(line3);
private static void gridEdit_MouseLeave(object sender, MouseEventArgs e)
{
line1.Stroke = Brushes.White;
line2.Stroke = Brushes.White;
line3.Stroke = Brushes.White;
}
private static void gridEdit_MouseEnter(object sender, MouseEventArgs e)
{
line1.Stroke = Brushes.Black;
line2.Stroke = Brushes.Black;
line3.Stroke = Brushes.Black;
}

Set the background color of your Grid to Transparent, this will allow the Grid to capture the mouse events.

Unexpected NullReferenceException / InvocationTargetException

I have a pointing to null error but i dont see where the problem is since everything gets initalised before used. the points where the error acures i have given a blockquote. Like always im thankfull for every help.
Button topAddBut = null;
//Button botAddBut = null;
Button loadBut = null;
Button saveBut = null;
StackPanel topSP = null;
//StackPanel botSP = null;
public MainWindow()
{
InitializeComponent();
loadBut = new Button { Content = "Load", Width = 70, Height = 23 };
Canvas.SetRight(loadBut, 160);
Canvas.SetBottom(loadBut, 24);
canvas1.Children.Add(loadBut);
saveBut = new Button { Content = "Save", Width = 70, Height = 23 };
Canvas.SetRight(saveBut, 80);
Canvas.SetBottom(saveBut, 24);
canvas1.Children.Add(saveBut);
StackPanel topSP = new StackPanel { Width = 400, Height = 50 };
Canvas.SetLeft(topSP, 160);
Canvas.SetTop(topSP, 100);
AddWrapPanelTop();
AddTextBoxTop();
AddTopButton();
}
void AddTextBoxTop()
{
TextBox txtB1 = new TextBox();
txtB1.Text = "Text";
txtB1.Width = 75;
txtB1.Height = 75;
WrapPanel wp = (WrapPanel)topSP.Children[0];
wp.Children.Add(txtB1);
}
void AddWrapPanelTop()
{
WrapPanel myWrapPanel = new WrapPanel();
SolidColorBrush mySolidColorBrush = new SolidColorBrush();
mySolidColorBrush.Color = Color.FromArgb(255, 0, 0, 255);
myWrapPanel.Background = System.Windows.Media.Brushes.Magenta;
myWrapPanel.Orientation = Orientation.Horizontal;
myWrapPanel.Width = 4000;
myWrapPanel.HorizontalAlignment = HorizontalAlignment.Left;
myWrapPanel.VerticalAlignment = VerticalAlignment.Top;
topSP.Children.Add(myWrapPanel);
}
void AddTopButton()
{
TextBox txtB1 = new TextBox();
txtB1.Background = System.Windows.Media.Brushes.Magenta;
txtB1.Text = "Text";
txtB1.Width = 75;
txtB1.Height = 75;
topAddBut = new Button();
topAddBut.Click += new RoutedEventHandler(this.TopClick);
topAddBut.Content = "Add";
topAddBut.Width = 75;
// Add the buttons to the parent WrapPanel using the Children.Add method.
WrapPanel wp = (WrapPanel)topSP.Children[0];
wp.Children.Add(txtB1);
wp.Children.Add(loadBut);
this.topSP.Children.Add(wp);
}
void TopClick(Object sender, EventArgs e)
{
TextBox txtB1 = new TextBox();
txtB1.Background = System.Windows.Media.Brushes.Magenta;
txtB1.Text = "Text";
txtB1.Width = 75;
txtB1.Height = 75;
Button s = (Button)sender;
WrapPanel wp = (WrapPanel)s.Parent;
wp.Children.Remove(s);
wp.Children.Add(txtB1);
AddTopButton();
// Add the buttons to the parent WrapPanel using the Children.Add method.
}
}
}

You define the following:
StackPanel topSP = null;
Then you have
StackPanel topSP = new StackPanel { Width = 400, Height = 50 };
This is in your local scope though so will be destroyed when you exit the function
Finally you have
topSP.Children.Add(myWrapPanel);
This will still be set to null which is why your error occurs. Basically you are creating a local version of the same variable.
In order to resolve simply change the second definition to:
topSP = new StackPanel { Width = 400, Height = 50 };

Expanding Wrap Panels ony in Width and other shenanigans

I want to expand a Wrap Panel only in width also the Wrap Panel shall not draw over another Stack Panel that already exists. The Problem is probably with the standard configuration of Buttons which i added to the wrap panel also my lack of knowledge about auto sizing, so content or guides to this topic would be appreciated. The Button i add to wrap panel shall add text boxes to it, but how i said just in the width.
Edit.: is there a way to add a visual studio projekt to a post/comment?
{
/// <summary>
/// Interaktionslogik für MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
stackPanel1.Width = Double.NaN;
stackPanel1.Height = Double.NaN;
stackPanel2.Width = Double.NaN;
stackPanel2.Height = Double.NaN;
AddWrapPanelMaster();
}
Button AddButtonSlave(Button but)
{
but.Click += new RoutedEventHandler(this.buttClickSlave);
return (but);
}
Button AddButtonMaster(Button but)
{
but.Click += new RoutedEventHandler(this.buttClickMaster);
return (but);
}
void buttClickMaster(Object sender, EventArgs e)
{
TextBox txtB1 = new TextBox();
txtB1.Text = "Text";
txtB1.Width = 75;
txtB1.Height = 75;
Button s = (Button)sender;
WrapPanel wp = (WrapPanel)s.Parent;
wp.Children.Add(txtB1);
}
void buttClickSlave(Object sender, EventArgs e)
{
Button s = (Button)sender;
if (s.Background != Brushes.Blue && s.Background != Brushes.Red && s.Background != Brushes.Green)
s.Background = Brushes.Red;
else
if (s.Background == Brushes.Green)
s.Background = Brushes.Red;
else
if (s.Background == Brushes.Blue)
s.Background = Brushes.Green;
else
if (s.Background == Brushes.Red)
s.Background = Brushes.Blue;
}
void AddTextBox(Button sender) {
TextBox txtB1 = new TextBox();
txtB1.Text = "Text";
txtB1.Width = 75;
txtB1.Height = 75;
WrapPanel s = (WrapPanel)sender.Parent;
s.Children.Add(txtB1);
// Add the buttons to the parent WrapPanel using the Children.Add method.
}
void AddWrapPanelSlave() {
WrapPanel myWrapPanel = new WrapPanel();
myWrapPanel.Background = System.Windows.Media.Brushes.Azure;
myWrapPanel.Orientation = Orientation.Horizontal;
myWrapPanel.Width = 200;
myWrapPanel.HorizontalAlignment = HorizontalAlignment.Left;
myWrapPanel.VerticalAlignment = VerticalAlignment.Top;
// Define 3 button elements. The last three buttons are sized at width
// of 75, so the forth button wraps to the next line.
Button btn1 = new Button();
btn1 = AddButtonSlave(btn1);
btn1.Content = "Button 1";
btn1.Width = 75;
Button btn2 = new Button();
btn2.Content = "Button 2";
btn2.Width = 75;
// Add the buttons to the parent WrapPanel using the Children.Add method.
myWrapPanel.Children.Add(btn1);
myWrapPanel.Children.Add(btn2);
this.stackPanel1.Children.Add(myWrapPanel);
}
void AddWrapPanelMaster()
{
WrapPanel myWrapPanel = new WrapPanel();
myWrapPanel.Background = System.Windows.Media.Brushes.Azure;
myWrapPanel.Orientation = Orientation.Horizontal;
myWrapPanel.Width = 200;
myWrapPanel.HorizontalAlignment = HorizontalAlignment.Left;
myWrapPanel.VerticalAlignment = VerticalAlignment.Top;
// Define 3 button elements. The last three buttons are sized at width
// of 75, so the forth button wraps to the next line.
TextBox txtB1 = new TextBox();
txtB1.Text = "Text";
txtB1.Width = 75;
txtB1.Height = 75;
Button btn1 = new Button();
btn1 = AddButtonMaster(btn1);
btn1.Content = "Add";
btn1.Width = 75;
// Add the buttons to the parent WrapPanel using the Children.Add method.
myWrapPanel.Children.Add(txtB1);
myWrapPanel.Children.Add(btn1);
this.stackPanel2.Children.Add(myWrapPanel);
}
private void button1_Click(object sender, RoutedEventArgs e)
{
AddWrapPanelSlave();
this.Show();
}
}
}

Add label under button in a flowLayoutPanel

I need to dynamically create buttons with labels under them in a flowLayoutPanel when i drop a file onto the form. But how do I set the label position to be under the button since the FLP is arranging the controls by itself.. ?
What I've tried:
void Form1_DragDrop(object sender, DragEventArgs e)
{
string[] fileList = e.Data.GetData(DataFormats.FileDrop) as string[];
foreach (string s in fileList)
{
Button button = new Button();
button.Click += new EventHandler(this.button_Click);
fl_panel.Controls.Add(button);
Icon icon = System.Drawing.Icon.ExtractAssociatedIcon(filename);
Bitmap bmp = icon.ToBitmap();
button.BackgroundImage = bmp;
button.Width = 60;
button.Height = 75;
button.FlatStyle = FlatStyle.Flat;
button.BackgroundImageLayout = ImageLayout.Stretch;
int space = 5;
int Yy = button.Location.Y;
int Xx = button.Location.X;
Label label = new Label();
label.Location = new Point(Yy + space, Xx);
//label.Margin.Top = button.Margin.Bottom;
fl_panel.Controls.Add(label);
}
}

The best idea I know of is to implement a custom control that contains both a button and a label that are arranged correctly. Then add the custom control to the FlowLayoutPanel.
public class CustomControl:Control
{
private Button _button;
private Label _label;
public CustomControl(Button button, Label label)
{
_button = button;
_label = label;
Height = button.Height + label.Height;
Width = Math.Max(button.Width, label.Width);
Controls.Add(_button);
_button.Location = new Point(0,0);
Controls.Add(_label);
_label.Location = new Point(0, button.Height);
}
}
You can then add to it like this:
for (int i = 0; i < 10; i++)
{
CustomControl c = new CustomControl(new Button {Text = "Button!"}, new Label {Text = "Label!"});
fl_panel.Controls.Add(c);
}
EDIT:
If you want to listen to button events, try this:
for (int i = 0; i < 10; i++)
{
var button = new Button {Text = "Button " + i};
CustomControl c = new CustomControl(button, new Label {Text = "Label!"});
button.Click += buttonClicked;
fl_panel.Controls.Add(c);
}
...
private void buttonClicked(object sender, EventArgs e)
{
MessageBox.Show(((Button) sender).Text);
}

Create an event handler for control created programmatically

I am working on a WPF application and what I want is if a specific Radio Button from group A is selected the program creates a second set of Radio Buttons call them group B and at the same time a disabled textbox. Now I want to create an event so if the user Selects option 3 from Group B the text box becomes enabled and when it is unselected it disables again. Now I have the working programmatically but when I try to create the event handlers I am referencing a non-existent control and it won't build. I am trying to use this.textBox.IsEnabled = true/false; to enable/disable the textbox. So just to make sure the actual question is clear. How can I enable/disable a textbox which doesn't exist at build/runtime?
My Events:
private void AllowRegion(object sender, RoutedEventArgs e)
{
this.SpecRegionText.IsEnabled = true;
}
private void DisallowRegion(object sender, RoutedEventArgs e)
{
this.SpecRegionText.IsEnabled = false;
}
Creating the controls:
private void AddSpecificControls()
{
Grid grid = (Grid)this.SpecsGrid;
RadioButton recruitmentEnabled = (RadioButton)this.RecruitmentEnabled;
if ((bool)recruitmentEnabled.IsChecked)
{
RadioButton newNations = new RadioButton();
newNations.Margin = new Thickness(10, 10, 0, 0);
newNations.HorizontalAlignment = HorizontalAlignment.Left;
newNations.Name = "NewNations";
newNations.GroupName = "RecruitType";
newNations.Content = "New Nations";
newNations.Width = 124;
grid.Children.Add(newNations);
RadioButton reFound = new RadioButton();
reFound.Margin = new Thickness(10, 30, 0, 0);
reFound.HorizontalAlignment = HorizontalAlignment.Left;
reFound.Name = "Refound";
reFound.GroupName = "RecruitType";
reFound.Content = "Refounded Nations";
reFound.Width = 124;
grid.Children.Add(reFound);
RadioButton specRegionRadio = new RadioButton();
specRegionRadio.Margin = new Thickness(10, 50, 0, 0);
specRegionRadio.HorizontalAlignment = HorizontalAlignment.Left;
specRegionRadio.VerticalAlignment = VerticalAlignment.Top;
specRegionRadio.Name = "SpecRegionRadio";
specRegionRadio.GroupName = "RecruitType";
specRegionRadio.Content = "Specific Region";
specRegionRadio.Width = 124;
specRegionRadio.Height = 23;
specRegionRadio.Checked += new RoutedEventHandler(AllowRegion);
specRegionRadio.Unchecked += new RoutedEventHandler(DisallowRegion);
grid.Children.Add(specRegionRadio);
TextBox specRegionText = new TextBox();
specRegionText.Margin = new Thickness(139, 50, 0, 0);
specRegionText.HorizontalAlignment = HorizontalAlignment.Left;
specRegionText.VerticalAlignment = VerticalAlignment.Top;
specRegionText.Name = "SpecRegionText";
specRegionText.Text = "Region";
specRegionText.Width = 120;
specRegionText.Height = 23;
specRegionText.IsEnabled = false;
grid.Children.Add(specRegionText);
}
}

You can hook delegate inline using lambda but for that you have to declare textBox before radioButton.
TextBox specRegionText = new TextBox();
RadioButton specRegionRadio = new RadioButton();
specRegionRadio.Checked += (s,e) => specRegionText.IsEnabled = true;
specRegionRadio.Unchecked += (s,e) => specRegionText.IsEnabled = false;