I’m trying to show and hide a pop-up when certain events occur. The pop-up is appearing and disappearing properly, but all of its labels are blank. I originally was trying to populate the labels prior to showing the form, but I’ve commented-out all of that logic. The labels are all blank, but the space is properly allocated for each label (see screenshot).
my popup control:
public MyPopUp()
{
InitializeComponent();
}
my separate class:
MyPopUp _MyPopUp;
protected override void OnLoad(IServiceProvider myServiceProvider)
{
_MyPopUp = new MyPopUp();
}
protected override void WhenSomethingHappens() {
_MyPopUp.Show();
}
protected override void WhenSomethingElseHappens() {
_MyPopUp.Hide();
}
Here is part of my designer.cs file. I've only copy/pasted the code from one of the labels, but the other 5 labels on the form have nearly-identical code.
private System.Windows.Forms.Label label1;
private void InitializeComponent()
{
this.label1 = new System.Windows.Forms.Label();
this.SuspendLayout();
//
// label1
//
this.label1.AutoSize = true;
this.label1.Location = new System.Drawing.Point(58, 9);
this.label1.Name = "label1";
this.label1.Size = new System.Drawing.Size(41, 13);
this.label1.TabIndex = 0;
this.label1.Text = "Some Label Text";
//
// MyPopUp
//
this.Controls.Add(this.label1);
this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
this.Name = "MyPopUp";
this.Text = "Some Text";
this.ResumeLayout(false);
this.PerformLayout();
}
You need to call Refresh() function to force every child control to invalidate, i.e. redraw, its client area.
For your case:
protected override void WhenSomethingHappens() {
_MyPopUp.Show();
_MyPopUp.Refresh();
}
This is happening because you are running the form modelessly.
If you want to you can check that your font/background colours are good etc. by running it Modally:
System.Windows.Forms.Application.Run(YourFormName);
then add the DoEvent line to your modeless call:
Form2 F2 = new Form2();
F2.Show();
System.Windows.Forms.Application.DoEvents();
and that should do it!
I have made a test and found a possibility to make the Label Text disappear. The Label Text disappears if the ForeColor is the same as the BackColor. From your Label-adding code, I see that you didn't specify these colors. WinForms Controls inherit a lot of properties from the parent control (in this case the Form itself), if they are not defined. This probably means that ForeColor and BackColor of the Form are the same and this propagates to the labels. Either change the ForeColor color of the Form or of the Label to fix this issue.
Try to invoke before showing the form, this way the form will be created in the main thread.
if (this.InvokeRequired)
this.BeginInvoke((Action)(() => //'this.' is the form
{
_MyPopUp.Show();
}));
Related
I have an Android application that uses Back Command to go back to the start screen.
The start screen has a label with a number inside, that I want to update when the back command is used.
I could figure out a solution with the code inside the back command, but I don't know if my approach is the best, since the ClassOne gets sort of loaded twice.
Here is the code I already have:
public class ClassOne {
public ClassOne(ClassPojo classPojo) {
// I want to change the text of this label when calling the back command
labelOne.setText(classPojo.getStringTest());
formOne.show();
}
}
public class ClassTwo {
public ClassTwo(Form a , ClassPojo classPojo) {
Command back = new Command("A") {
#Override
public void actionPerformed(ActionEvent evt) {
// I am adding the new value for the label here inside the back command
classPojo.setStringTest("testing");
a.showBack();
new ClassOne(classPojo);
}
};
formTwo.setBackCommand(back);
}
I'm not sure what the problem is, your example is a bit generic. However, a complete minimal example where the startScreen form instance is not recreated is this one:
Form startScreen = new Form("Start screen", BoxLayout.y());
Wrapper<Integer> count = new Wrapper<>(1);
Label numberLabel = new Label(count.get() + "");
Button button1 = new Button("Go to Form 2");
startScreen.addAll(numberLabel, button1);
startScreen.show();
button1.addActionListener(l -> {
Form form2 = new Form("Form 2", BoxLayout.y());
Label label = new Label("Use the back button");
form2.add(label);
form2.getToolbar().setBackCommand("Back", Toolbar.BackCommandPolicy.ALWAYS, ll -> {
count.set(count.get() + 1);
numberLabel.setText(count.get() + "");
startScreen.showBack();
});
form2.show();
});
If you don't even want to recreate the form2 instance, then you can do so:
Form startScreen = new Form("Start screen", BoxLayout.y());
Wrapper<Integer> count = new Wrapper<>(1);
Label numberLabel = new Label(count.get() + "");
Button button1 = new Button("Go to Form 2");
startScreen.addAll(numberLabel, button1);
startScreen.show();
Form form2 = new Form("Form 2", BoxLayout.y());
Label label = new Label("Use the back button");
form2.add(label);
form2.getToolbar().setBackCommand("Back", Toolbar.BackCommandPolicy.ALWAYS, ll -> {
count.set(count.get() + 1);
numberLabel.setText(count.get() + "");
startScreen.showBack();
});
button1.addActionListener(l -> {
form2.show();
});
In my opinion, whether or not to recreate the instances of a Form should be evaluated on a case-by-case basis. Among the variables between taking into consideration, according to my modest opinion, there is also the readability of the code and what it does, especially in complex cases.
The overhead of recreating a form instance is negligible so that wouldn't be a problem but in recent years we try to reuse form instances more. Not because of the performance.
The benefit is in minor behaviors e.g. scroll position within the form. These are very hard to replicate.
During testing, I found an easy solution that is adding the label to the constructor. I hope this snippet can be helpful.
public ClassTwo(Form a, ClassPojo classPojo, Label label) {
Command back = new Command("A") {
#Override
public void actionPerformed(ActionEvent evt) {
label.setText(classPojo.getStringTest());
a.showBack();
}
};
I create a winform project with a single form with 4 textboxes and a button.
On button click, I perform the following:
Window1 w = new Window1();
ElementHost.EnableModelessKeyboardInterop(w);
w.Show();
Where window 1 is a Wpf window. Window1 has a single button on it and when that button is clicked the following occurs:
System.Windows.MessageBox.Show("HelloWOrld");
When you run the application the WinForm Form pops ups. If you hit tab it cycles through the 4 textboxes no problem. Then Click the button to open the WPF window. Click that button and popup the messagebox. Leave them open and then go back to the WinForm form you can no longer tab through the fields but you can type other characters. It appears as though the textboxes get the keystrokes but the form doesn't get them. I also get a system beep as though the model was getting the keystroke.
EDIT 9/9/2014 3:44PM
Hans responded in the comments and was correct. I tried describing a simpler case that would be easier for other people to reproduce that gave use the same symptoms. Our actual problem is that we have created a window base class that supports modal to parent capabilities. Here is the relevant code for our BaseWindow
public class BaseWindow: Window
{
[DllImport("user32.dll")]
static extern bool EnableWindow(IntPtr hWnd, bool bEnable);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool SetForegroundWindow(IntPtr hWnd);
public void ShowModalToParent(Window frmParent, Action<bool?> callback = null)
{
IntPtr myHandle = (new System.Windows.Interop.WindowInteropHelper(this)).Handle;
EnableWindow(myHandle,
SetForegroundWindow(myHandle);
this.Closing += Window_Closing;
ShowInTaskbar = false;
Owner = frmParent; // Keep on top of parent
ClosedCallBack += callback ?? (p => { _modalDialogResult = p; });
var parentHandle = (new System.Windows.Interop.WindowInteropHelper(frmParent)).Handle;
EnableWindow(parentHandle, false); // Prevent events for parent
new ShowAndWaitHelper(this).ShowAndWait();
}
internal class ShowAndWaitHelper
{
private readonly Window _window;
private DispatcherFrame _dispatcherFrame;
internal ShowAndWaitHelper(Window window)
{
if (window == null)
{
throw new ArgumentNullException("panel");
}
this._window = window;
}
internal void ShowAndWait()
{
if (this._dispatcherFrame != null)
{
throw new InvalidOperationException("Cannot call ShowAndWait while waiting for a previous call to ShowAndWait to return.");
}
this._window.Closed += new EventHandler(this.OnPanelClosed);
_window.Show();
this._dispatcherFrame = new DispatcherFrame();
Dispatcher.PushFrame(this._dispatcherFrame);
}
private void OnPanelClosed(object source, EventArgs eventArgs)
{
if (this._dispatcherFrame == null)
{
return;
}
this._window.Closed -= new EventHandler(this.OnPanelClosed);
this._dispatcherFrame.Continue = false;
this._dispatcherFrame = null;
}
}
}
I'm sure this code was taken from a Blog/Forum post of some sort but am unable to find any reference to it in code. We want to keep the modal to parent but some how address the odd key press issue. To reproduce the issue replace the button_click in Window1 to call ShowModalToParent on a window that uses this as a base class.
I am having issues updating the text in a tooltip for a system tray application. I have a timer updating several strings, but it will not update the notifyicon text. Here is what I have tried.
//This is in my main
System.Timers.Timer aTimer = new System.Timers.Timer();
aTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent);
aTimer.Interval = 5000;
aTimer.Enabled = true;
}
private static void OnTimedEvent(object sender, ElapsedEventArgs e)
{
ProcessIcon.GetDNS();
ProcessIcon.GetIP();
ProcessIcon.getMAC();
ProcessIcon.showALL();
Fixes.SetNotifyIconText(ni, ProcessIcon.showALL()); //This one will not update, the others update fine.
}//End part of my main
//This part is in another class for the notifyicon part.
public void Display()
{
// Put the icon in the system tray and allow it react to mouse clicks.
ni.MouseClick += new MouseEventHandler(ni_MouseClick1);
ni.Icon = new Icon("WhoAmI.ico");
Fixes.SetNotifyIconText(ni, showALL());
ni.Visible = true;
// Attach a context menu.
ni.ContextMenuStrip = new ContextMenus().Create();
}
I removed the timer and now call each function when the user hovers over the icon.
Using VS2010 and .NET 4.0 with C# and WinForms:
I always want a Vertical Scrollbar to show for my panel as a disabled scrollbar (when it's not needed, and a enabled one when it can be used.
So it's like a hybrid AutoScroll. I've tried using VScrollBars but I can't figure out where to place them to make this work.
Essentially I've got a user control that acts as a "Document" of controls, its size changes so when using auto-scroll it works perfectly. The scrollbar appears when the usercontrol doesn't fit and the user can move it updown.
It's like a web browser essentially. However, redrawing controls takes a long time (it's forms with many fields and buttons etc within groups in a grid within a panel :P
So anyhow, when autoscroll enables the vertical scrollbar, it takes a while to redraw the window. I'd like to ALWAYS show the vertical scrollbar as indicated above (with the enable/disable functionality).
If anyone has some help, i've read many posts on the subject of autoscroll, but noone has asked what I'm asking and I can't come up with a solution.
C# Version of competent_Tech's answer
using System.Runtime.InteropServices;
public class MyUserControl : UserControl
{
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool ShowScrollBar(IntPtr hWnd, int wBar, bool bShow);
private enum ScrollBarDirection
{
SB_HORZ = 0,
SB_VERT = 1,
SB_CTL = 2,
SB_BOTH = 3
}
public MyUserControl()
{
InitializeComponent();
ShowScrollBar(this.Handle, (int) ScrollBarDirection.SB_VERT, true);
}
}
You can use the auto-scroll functionality of the panel, you just need to send it a windows message to show the vertical scrollbar:
<DllImport("user32.dll")> _
Public Shared Function ShowScrollBar(ByVal hWnd As System.IntPtr, ByVal wBar As Integer, ByVal bShow As Boolean) As Boolean
End Function
Private Const SB_VERT As Integer = 1
Public Sub New()
' This call is required by the designer.
InitializeComponent()
ShowScrollBar(Panel1.Handle, SB_VERT, True)
End Sub
The scrollbar will be displayed and appear as though it can be scrolled, but it won't do anything until it is actually ready to scroll. If you disable it, it won't be automatically re-enabled, so this is probably the best approach.
Also, to improve the performance while resizing, you can call SuspendLayout on the panel before updating and ResumeLayout when done.
What worked for me was overriding the CreateParams call and enabling the WS_VSCROLL style.
public class VerticalFlowPanel : FlowLayoutPanel
{
protected override CreateParams CreateParams
{
get
{
var cp = base.CreateParams;
cp.Style |= 0x00200000; // WS_VSCROLL
return cp;
}
}
}
The AutoScroll logic will now adjust the scrolling bounds without ever hiding the scrollbar.
Here is what solved this for me. My case is that I have a panel sandwiched between another three panels with no degree of liberty in any direction. I needed this panel to be so big that the whole structure would go out of my 1920x1080 screen.
The solution is actually very simple.
For the panel that needs scroll bars set the AutoScroll property to true. Then, add on it another control in the far right far down position (right-bottom position). The control I choose is a label which I made invisible.... And that is all.
Now my panel occupies its restricted area, but I can scroll to the size that I needed and use it for the size I need.
If you only need horizontal scroll bars add the invisible control outside left, for vertical only far down bottom.
The actual size of the panel is the one you restrict it to when display it, but the virtual size is dictated by the invisible control.
This code will draw a disabled vertical scrollbar whenever the built in scrollbar of the Panel is invisible. The codes assumes that
AutoScroll = true;
AutoSize = false;
The following code is speed-optimized. It does as few as possible in OnPaint().
Derive a class from Panel.
Add these member variables:
// NOTE: static variables are not thread safe.
// But as we have only one GUI thread this does not matter.
static IntPtr mh_ScrollTheme = IntPtr.Zero;
static int ms32_ScrollWidth = SystemInformation.VerticalScrollBarWidth;
Win32.RECT mk_ScrollTop;
Win32.RECT mk_ScrollBot; // coordinates of top scrollbar button
Win32.RECT mk_ScrollShaft; // coordinates of bottom scrollbar button
Then override OnSizeChanged:
protected override void OnSizeChanged(EventArgs e)
{
base.OnSizeChanged(e);
Win32.RECT k_ScrollBar = new Win32.RECT(ClientRectangle);
k_ScrollBar.Left = k_ScrollBar.Right - ms32_ScrollWidth;
mk_ScrollTop = new Win32.RECT(k_ScrollBar);
mk_ScrollBot = new Win32.RECT(k_ScrollBar);
mk_ScrollShaft = new Win32.RECT(k_ScrollBar);
int s32_Upper = k_ScrollBar.Top + ms32_ScrollWidth;
int s32_Lower = k_ScrollBar.Bottom - ms32_ScrollWidth;
mk_ScrollTop .Bottom = s32_Upper;
mk_ScrollBot .Top = s32_Lower;
mk_ScrollShaft.Top = s32_Upper;
mk_ScrollShaft.Bottom = s32_Lower;
}
And paint the scrollbar when required:
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
if (VScroll)
return; // The 'real' scrollbar is visible
if (mh_ScrollTheme == IntPtr.Zero)
mh_ScrollTheme = Win32.OpenThemeData(Handle, "SCROLLBAR");
if (mh_ScrollTheme == IntPtr.Zero)
return; // The user has disabled themes
// Draw the disabled vertical scrollbar.
IntPtr h_DC = e.Graphics.GetHdc();
// Draw shaft
const int SBP_UPPERTRACKVERT = 7;
const int SCRBS_DISABLED = 4;
Win32.DrawThemeBackground(mh_ScrollTheme, h_DC, SBP_UPPERTRACKVERT, SCRBS_DISABLED, ref mk_ScrollShaft, IntPtr.Zero);
// Draw top button
const int SBP_ARROWBTN = 1;
const int ABS_UPDISABLED = 4;
Win32.DrawThemeBackground(mh_ScrollTheme, h_DC, SBP_ARROWBTN, ABS_UPDISABLED, ref mk_ScrollTop, IntPtr.Zero);
// Draw lower button
const int ABS_DOWNDISABLED = 8;
Win32.DrawThemeBackground(mh_ScrollTheme, h_DC, SBP_ARROWBTN, ABS_DOWNDISABLED, ref mk_ScrollBot, IntPtr.Zero);
e.Graphics.ReleaseHdc(h_DC);
}
For some years, the answer of BradJ and fiat worked for me. Now I needed to show the disabled scrollbar look. But I failed to find the correct way… So here is my workaround.
The code bellow just draw the disabled scrollbar at the position of the real scrollbar.
THE CODE
using System;
using System.Drawing;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;
public class VerticalFlowPanel : FlowLayoutPanel
{
public VerticalFlowPanel()
{
AutoScroll = true;
}
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
var width = Width;
var height = Height;
var vsWidth = SystemInformation.VerticalScrollBarWidth;
var vsHeight = SystemInformation.VerticalScrollBarArrowHeight;
var left = width - vsWidth;
var sbUpper = new Rectangle(left, 0, vsWidth, height / 2);
var sbLower = new Rectangle(left, sbUpper.Height, vsWidth, height - sbUpper.Height);
var arUp = new Rectangle(left, 0, vsWidth, vsHeight);
var arDown = new Rectangle(left, height - vsHeight, vsWidth, vsHeight);
ScrollBarRenderer.DrawUpperVerticalTrack(e.Graphics, sbUpper, ScrollBarState.Disabled);
ScrollBarRenderer.DrawLowerVerticalTrack(e.Graphics, sbLower, ScrollBarState.Disabled);
ScrollBarRenderer.DrawArrowButton(e.Graphics, arUp, ScrollBarArrowButtonState.UpDisabled);
ScrollBarRenderer.DrawArrowButton(e.Graphics, arDown, ScrollBarArrowButtonState.DownDisabled);
}
// Necessary to avoid visual artifacts
protected override void OnSizeChanged(EventArgs e)
{
base.OnSizeChanged(e);
var width = Width;
var height = Height;
var vsWidth = SystemInformation.VerticalScrollBarWidth;
var scrollBounds = new Rectangle(width - vsWidth, 0, vsWidth, height);
Invalidate(scrollBounds);
}
}
NOTE
This is not the best solution. But it was easier than migrate my hole solution to WPF…
I want to have a TextBox which Height grows as Iam entering lines of Text.
I've set the Height property to "Auto", and so far the growing works.
Now I want that the TextBox's Height should be at least 5 lines.
Now I've set the MinLines property to "5" but if I start the app the TextBox's height is still one line.
Try setting the MinHeight property.
A hack to make the MinLines property work
public class TextBoxAdv : TextBox
{
bool loaded = false;
/// <summary>
/// Constructor
/// </summary>
public TextBoxAdv()
{
Loaded += new RoutedEventHandler( Control_Loaded );
SetResourceReference( StyleProperty, typeof( TextBox ) );
}
void Control_Loaded( object sender, RoutedEventArgs e )
{
if( !loaded )
{
loaded = true;
string text = Text;
Text = "Text";
UpdateLayout();
Text = text;
}
}
}
I propose a different solution that properly respects the MinLines property, rather than forcing you to use MinHeight.
First, start with a convenience method to allow you to Post an action to the window loop. (I'm including both one where you need to pass state and one where you don't.)
public static class Globals {
public static void Post(Action callback){
if(SynchronizationContext.Current is SynchronizationContext currentContext)
currentContext.Post( _ => callback(), null);
else{
callback();
}
}
public static void Post<TState>(TState state, Action<TState> callback){
if(SynchronizationContext.Current is SynchronizationContext currentContext)
currentContext.Post(_ => callback(state), null);
else{
callback(state);
}
}
}
Next, create an extension method for TextBox to 'initialize' the proper size based on MinLines. I put this in a Hacks class because to me, that's what this is and it clearly identifies the code as such.
public static void FixInitialMinLines(this TextBox textBox) {
Globals.Post(() => {
var textBinding = textBox.GetBindingExpression(TextBox.TextProperty)?.ParentBinding;
if (textBinding != null) {
BindingOperations.ClearBinding(textBox, TextBox.TextProperty);
textBox.UpdateLayout();
BindingOperations.SetBinding(textBox, TextBox.TextProperty, textBinding);
}
else {
var lastValue = textBox.Text;
textBox.Text = lastValue + "a";
textBox.UpdateLayout();
textBox.Text = lastValue;
}
});
}
The above code handles both bound and unbound TextBox controls, but rather than simply changing the value like other controls which may cascade that change down through the bindings, it first disconnects the binding, forces layout, then reconnects the binding, thus triggering the proper layout in the UI. This avoids unintentionally changing your bound sources should the binding be two-way.
Finally, simply call the extension method for every TextBox where MinLines is set. Thanks to the Post call in the extension method, You can call this immediately after InitializeComponent and it will still be executed after all other events have fired, including all layout and the Loaded event.
public partial class Main : Window {
public Main() {
InitializeComponent();
// Fix initial MinLines issue
SomeTextBoxWithMinLines.FixInitialMinLines();
}
...
}
Add the above code to your 'library' of functions and you can address the issue with a single line of code in all of your windows and controls. Enjoy!