so I have a richtextbox and a form, and have attached a drag enter and drop event to them. The code for both of them are EXACTLY the same, I've made sure of it, but for some reason, the richtextbox event activates the Text Changed event. The form would activate the text changed event aswell, but I have a variable in the method that I call from the drag event that blocks it. I've tried to reproduce it on a different form, but the main kicker is that the code for the forms drag and drop events are EXACTLY the same as the richtextbox drag drop events. How could they possibly be different? Here is the drop drop code:
private void TestBox_DragEnter(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(DataFormats.FileDrop))
e.Effect = DragDropEffects.Copy;
}
private async void TestBox_DragDrop(object sender, DragEventArgs e)
{
string filePath = ((string[])e.Data.GetData(DataFormats.FileDrop))[0];
await AsyncStuff();
}
private async Task AsyncStuff()
{
block = true;
await OtherAsyncMethodThatActivatesTextChanged();
block = false;
}
private bool block;
private void TestBox_TextChanged(object sender, EventArgs e)
{
if (block) return;
MessageBox.Show("Text Changed called"); //Activates on the richtextbox drag, doesn't on the form
}
I am able to reproduce it now, here is the code. I attached the form drag drop and enter events through the designer.
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
richTextBox1.AllowDrop = true;
richTextBox1.TextChanged += TestBox_TextChanged;
richTextBox1.DragDrop += TestBox_DragDrop;
richTextBox1.DragEnter += TestBox_DragEnter;
AllowDrop = true;
}
private void TestBox_DragEnter(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(DataFormats.FileDrop))
e.Effect = DragDropEffects.Copy;
}
private async void TestBox_DragDrop(object sender, DragEventArgs e)
{
string filePath = ((string[])e.Data.GetData(DataFormats.FileDrop))[0];
await AsyncStuff();
}
private async Task AsyncStuff()
{
block = true;
richTextBox1.AppendText("asd");
block = false;
}
private bool block;
private void TestBox_TextChanged(object sender, EventArgs e)
{
if (block) return;
MessageBox.Show("Text Changed called"); //Activates on the richtextbox drag, doesn't on the form
}
private async void Form1_DragDrop(object sender, DragEventArgs e)
{
string filePath = ((string[])e.Data.GetData(DataFormats.FileDrop))[0];
await AsyncStuff();
}
private void Form1_DragEnter(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(DataFormats.FileDrop))
e.Effect = DragDropEffects.Copy;
}
}
Related
I am trying to make a simple screen share application in C# and found this guide: https://www.c-sharpcorner.com/uploadfile/ulricht/how-to-create-a-simple-screen-sharing-application-in-C-Sharp/ and followed it but it doesn't work i tried it on the same computer and on two different PCs but nothing seems to work
//Host
public partial class ScreenShareHandler : Form
{
RDPSession x = new RDPSession();
public ScreenShareHandler()
{
InitializeComponent();
}
private void ScreenShareHandler_Load(object sender, EventArgs e)
{
}
private void Incoming(object Guest)
{
IRDPSRAPIAttendee MyGuest = (IRDPSRAPIAttendee)Guest;//???
MyGuest.ControlLevel = CTRL_LEVEL.CTRL_LEVEL_INTERACTIVE;
}
private void button1_Click(object sender, EventArgs e)
{
x.OnAttendeeConnected += Incoming;
x.Open();
}
private void button2_Click(object sender, EventArgs e)
{
IRDPSRAPIInvitation Invitation = x.Invitations.CreateInvitation("Trial", "MyGroup", "", 10);
textBox1.Text = Invitation.ConnectionString;
}
private void button3_Click(object sender, EventArgs e)
{
x.Close();
x = null;
}
}
//Client
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
string Invitation = textBox1.Text;// "";// Interaction.InputBox("Insert Invitation ConnectionString", "Attention");
axRDPViewer1.Connect(Invitation, "User1", "");
}
private void button2_Click(object sender, EventArgs e)
{
axRDPViewer1.Disconnect();
}
}
As written in my comments:
Have you hooked up the eventhandlers correctly? If you click on the button in the designer you can go to the Events Tab in the Property-window and check if the Click-event points to the right eventhandler. Another way to check if the correct handler is used is to put a breakpoint inside each handler. Then debug and check if you get into the right method when you click the button. If not you didn't hook up the Eventhandlers correctly.
I attached a TextBox to the first TabPage of a TabControl. I would like to display the same TextBox object on every TabPage. I tried to add the control to the tabControl Collection but unfortunately it's not working.
private void Form1_Load(object sender, EventArgs e)
{
tabControl1.TabPages[tabControl1.SelectedIndex].Controls.Add(textBox);
}
Button b;
public Form1()
{
InitializeComponent();
b = new Button() { Text = "Prueba" };
}
private void Form1_Load(object sender, EventArgs e)
{
AddButtonToTabControl();
}
private void tabControl1_SelectedIndexChanged(object sender, EventArgs e)
{
AddButtonToTabControl();
}
public void AddButtonToTabControl()
{
tabControl1.SelectedTab.Controls.Add(b);
}
I missed two methods. It's working now!
tabControl1.Selecting += new TabControlCancelEventHandler(tabControl1_Selecting);
void tabControl1_Selecting(object sender, TabControlCancelEventArgs e)
{
tabControl1.TabPages[tabControl1.SelectedIndex].Controls.Add(textBox);
}
I created a usercontrol that contains many buttons and in the main form I have a textbox.
I add the usercontrol to the main form and I want to click any button on the usercontrol and have the textbox in the main form shows the button text.
The question is how to pass the string of the button in usercontrol to the textbox in the main form? This is what I'm trying to do
public partial class UserControl1 : UserControl
{
public UserControl1()
{
InitializeComponent();
}
public string a ;
private void button1_Click(object sender, EventArgs e)
{
a = button1.Text;
}
private void button2_Click(object sender, EventArgs e)
{
a = button2.Text;
}
private void button3_Click(object sender, EventArgs e)
{
a = button3.Text;
}
and the main form code is :
private void textBox1_TextChanged(object sender, EventArgs e)
{
textBox1.Text = usrCtrl.a;
// usrCtrl come from : Usercontrol1 usrCtrl = new Usercontrol1();
}
and it shows nothing in the textbox.
refer to this answer, you need to create a property changed event.
UserControl.cs class;
public partial class UserControl1 : UserControl
{
public event PropertyChangedEventHandler PropertyChanged;
public UserControl1()
{
InitializeComponent();
}
private string stringA;
public string a
{
get { return stringA; }
set
{
if (value != stringA)
{
stringA = value;
if (PropertyChanged!= null)
{
PropertyChanged(this, new PropertyChangedEventArgs(a));
}
}
}
}
private void button1_Click(object sender, EventArgs e)
{
a = button1.Text;
}
private void button2_Click(object sender, EventArgs e)
{
a = button2.Text;
}
private void button3_Click(object sender, EventArgs e)
{
a = button3.Text;
}
private void button4_Click(object sender, EventArgs e)
{
a = button4.Text;
}
}
On Form's Load we need to define the event,
private void Form1_Load(object sender, EventArgs e)
{
cntr.PropertyChanged += Cntr_PropertyChanged; // press tab + tab after += and it will generate the following method automatically.
}
Here is Event;
private void Cntr_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
textBox1.Text = cntr.a.ToString(); //cntr is the instance of UserControl1
}
Hope helps,
Your code to change the textBox1.Text value is in the wrong event handler.
The textBox1_TextChanged event handler only fires when text in that field changes.
What you need to do is put the line:
textBox1.Text = a;
in the click event handlers.
Let's assume the following Situation:
a Control (e.g. a Button) has an attached behavior to enable a Drag&Drop-Operation
<Button Content="test">
<i:Interaction.Behaviors>
<SimpleDragBehavior/>
</i:Interaction.Behaviors>
</Button>
And the SimpleDragBehavior
public class SimpleDragBehavior: Behavior<Button>
{
protected override void OnAttached ()
{
AssociatedObject.MouseLeftButtonDown += OnAssociatedObjectMouseLeftButtonDown;
AssociatedObject.MouseLeftButtonUp += OnAssociatedObjectMouseLeftButtonUp;
AssociatedObject.MouseMove += OnAssociatedObjectMouseMove;
mouseIsDown = false;
}
private bool mouseIsDown;
private void OnAssociatedObjectMouseMove (object sender, MouseEventArgs e)
{
if (mouseIsDown)
{
AssociatedObject.Background = new SolidColorBrush(Colors.Red);
DragDrop.DoDragDrop((DependencyObject)sender,
AssociatedObject.Content,
DragDropEffects.Link);
}
}
private void OnAssociatedObjectMouseLeftButtonUp (object sender, MouseButtonEventArgs e)
{
mouseIsDown = false;
}
private void OnAssociatedObjectMouseLeftButtonDown (object sender, MouseButtonEventArgs e)
{
mouseIsDown = true;
}
}
The task now is to determine when the drag ends, to restore the orignal backgound of the button.
This is no problem when droped on an drop-target. But how do i recognize a drop on something which isn't a drop-target? In the worst case: outside the window?
DragDrop.DoDragDrop returns after drag-and-drop operation is completed.
Yes, "Initiates a drag-and-drop operation" is confusing, since it could be read as "start drag-and-drop and return":
private void OnAssociatedObjectMouseMove (object sender, MouseEventArgs e)
{
if (mouseIsDown)
{
AssociatedObject.Background = new SolidColorBrush(Colors.Red);
var effects = DragDrop.DoDragDrop((DependencyObject)sender,
AssociatedObject.Content,
DragDropEffects.Link);
// this line will be executed, when drag/drop will complete:
AssociatedObject.Background = //restore color here;
if (effects == DragDropEffects.None)
{
// nothing was dragged
}
else
{
// inspect operation result here
}
}
}
As I read in other questions, mostly peoples asks why it firing unexpectedly, but for me it never fires at all.
using System;
using System.Windows.Forms;
namespace TestDrag
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
treeView1.ItemDrag += treeView1_ItemDrag;
treeView1.DragLeave += treeView1_DragLeave;
groupBox1.AllowDrop = true;
groupBox1.DragEnter += groupBox1_DragEnter;
groupBox1.DragDrop += groupBox1_DragDrop;
treeView1.Nodes.Add("asd");
treeView1.Nodes.Add("dsa");
}
void groupBox1_DragDrop(object sender, DragEventArgs e)
{
throw new NotImplementedException();
}
void groupBox1_DragEnter(object sender, DragEventArgs e)
{
e.Effect = DragDropEffects.Copy;
}
void treeView1_ItemDrag(object sender, ItemDragEventArgs e)
{
treeView1.DoDragDrop(e.Item, DragDropEffects.Copy);
}
void treeView1_DragLeave(object sender, EventArgs e)
{
MessageBox.Show(this, "This message never shows when node dragged out of treeView1", "This is bad", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
}
I want to hide TreeView once item dragged out, but this event never occurs >_<
What could be the reason and how to fix or bypass this?
You have to make AllowDrop = True;