I have two forms; one of them is containing listview, and another one is just a form.
I want to make a thing :
If I drag an item in listview to a Form, a messagebox would be pop up.
and the message would be text of the item.
However I don't know why 'SelectedItem' is null. When I trace the SelectedItem, it was null.
I found I have to use MouseDown and DragDrop events, but I have no idea how to use.
First one is the listview's code :
rListCtrl.MouseDown += rListCtrl_MouseDown;
rListCtrl.DragDrop += rListCtrl_DragDrop;
private void rListCtrl_MouseDown(object sender, MouseEventArgs e)
{
StringBuilder sb = new STringBuilder();
sb.Append(radListView1.SelectedItem.ToString());
testName = sb.ToString();
}
private void rListCtrl_DragDrop(object sender, DragEventArgs e){
{
MessageBox.Show(testName);
}
radListView1 is the name of listview.
The reason why SelectedItem is null, is that the Item only gets selected when you actually perform a click, not a mere MouseDown.
You can, however, use the IndexFromPoint method to get the Item the mouse had been placed on when the MouseDown Event was evoked:
private void radListView1_MouseDown(object sender, MouseEventArgs e)
{
int index = radListView1.IndexFromPoint(e.Location);
radListView1.SelectedIndex = index;
testName = radListView1.Items[index].ToString();
}
private void rListCtrl_DragDrop(object sender, DragEventArgs e){
{
MessageBox.Show(testName);
}
Form1:
public partial class Form1 : Form
{
Form2 f = new Form2();
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
f.Show();
}
private void Form1_MouseEnter(object sender, EventArgs e)
{
if(f.data!= string.Empty)
{
MessageBox.Show(f.data);
f.data = string.Empty;
}
}
}
Form2:
public partial class Form2 : Form
{
public string data = string.Empty;
public Form2()
{
InitializeComponent();
listView1.ItemDrag += doDaragItem;
}
private void doDaragItem(Object sender, ItemDragEventArgs e)
{
data = e.Item.ToString();
}
}
Ron,
RadListView from the Telerik UI from WinForms suite handles the whole drag and drop operation by its ListViewDragDropService. Its PreviewDragOver event allows you to control on what targets the item(s) being dragged can be dropped on. The PreviewDragDrop event allows you to get a handle on all the aspects of the drag and drop operation, the source (drag) list view, the destination (target) control, as well as the item being dragged. Additional information is available in the following help article: https://docs.telerik.com/devtools/winforms/controls/listview/drag-and-drop/listviewdragdropservice
https://docs.telerik.com/devtools/winforms/controls/listview/drag-and-drop/drag-and-drop-using-raddragdropservice
You can also combine the RadDragDropService and OLE drag-and-drop functionality: https://docs.telerik.com/devtools/winforms/controls/listview/drag-and-drop/combining-raddragdropservice-and-ole-drag-and-drop
As to the specific code snippet, indeed, if you don't have a selected item in RadListView, the code in the MouseDown event won't extract the item's text. You need to get the element under the mouse and set the item as selected:
private void radListView1_MouseDown(object sender, MouseEventArgs e)
{
SimpleListViewVisualItem elementUnderMouse = this.radListView1.ElementTree.GetElementAtPoint(e.Location) as SimpleListViewVisualItem;
if (elementUnderMouse != null)
{
this.radListView1.SelectedItem = elementUnderMouse.Data ;
}
StringBuilder sb = new StringBuilder();
sb.Append(radListView1.SelectedItem.Text.ToString());
{
testName = sb.ToString();
}
MessageBox.Show(testName);
}
I hope this information helps.
Related
I'm new to C# so this is my first task essentially, I'm hoping to make a simple login page.
I would like the text to disappear from the textbox once it has been clicked, here's what I have tried so far;
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
bool hasBeenClicked = false;
private void textBox1_Focus(object sender, EventArgs e)
{
TextBox box = sender as TextBox;
box.Text = string.Empty;
hasBeenClicked = true;
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
}
}
This is from a similar post on here, It doesn't seem to work for me.
Here is something else I have tried;
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void textBox1_MouseClick(object sender, MouseEventArgs e)
{
textBox1.Text = "";
}
I understand it may be a silly mistake, I'm learning.
Any helps is massively appreciated :)
I'm using Winforms
Try using the event MouseClick on the TextBox:
private void textBox1_MouseClick(object sender, MouseEventArgs e)
{
this.textBox1.Text = "";
}
In your screenshot, you are missing a reference. Click into the textbox events and add it like so:
Both of which should probably work but you've got to link the event to the function. You can either do this in the Designer or in code. For the Mouse click variant to work and link the event in code you can add the following in the constructor:
public Form1()
{
InitializeComponent();
this.MouseClick += textbox1_MouseClick;
}
Add Event Handler
You have not linked the given methods with the event, as you can see 0 refereces for both functions. You can add a mouse Click event as:
textBox1.Click += new System.EventHandler(textbox1_Mouseclick);
Similarly, you have to add event if you want to do with the focus event.
I'm fairly new to programming so sorry if this is simple, but I might just be missing the obvious! I have the following form which is automatically populated on load from settings stored in an INI file:
The whole form is working just as I want it to apart form one small part. The 'Close' button currently just closes the form so that if any values have changed in the text boxes since the form was loaded, the changes are lost. I want to instead prompt the user to use the Save button instead otherwise the changes will be lost.
I've been trying to do something along these lines on my close button where the value of the text boxes are checked against the variable values that they were originally populated with:
private void btnClose_Click(object sender, EventArgs e)
{
if (txtName.Text != name || txtSchName.Text != schname || txtServer1.Text != svr1 etc etc etc)
{
Warn User changes will be lost, ask user if really OK to close?
if (User chooses to to close)
{
this.Close();
}
else
{
Go back to the config form;
}
}
else
{
this.Close();
}
With over 21 text fields, I was not sure if this was the most "tidy way" of checking for changes? Any pointers would be appreciated.
You just add a global boolean variable and write an handler for the TextChanged event
// Declared at the form level
private bool _modified = false;
public Form1()
{
InitializeComponent();
// This could be done in the form designer of course
// o repeated here for every textbox involved....
txtName.TextChanged += OnBoxesChanged;
......
}
private void Form1_Load(object sender, EventArgs e)
{
.....
// Code that initializes the textboxes could raise the TextChanged event
// So it is better to reset the global variable to an untouched state
_modified = false;
}
private void OnBoxesChanged(object sender, EventArgs e)
{
// Every textbox will call this event handler
_modified = true;
}
private void btnClose_Click(object sender, EventArgs e)
{
if(_modified)
{
// Save, warning, whatever in case of changes ....
}
}
Just set the event handler OnBoxesChanged for every textbox you want to trigger the condition. You could do it through the Designer or manually after the InitializeComponent call
What you are looking for is Dirty Tracking. Dirty tracking is used to track states of your control. Here is a simple reusable approach to track your controls
public class SimpleDirtyTracker
{
private Form _frmTracked;
private bool _isDirty;
public SimpleDirtyTracker(Form frm)
{
_frmTracked = frm;
AssignHandlersForControlCollection(frm.Controls);
}
// property denoting whether the tracked form is clean or dirty
public bool IsDirty
{
get { return _isDirty; }
set { _isDirty = value; }
}
// methods to make dirty or clean
public void SetAsDirty()
{
_isDirty = true;
}
public void SetAsClean()
{
_isDirty = false;
}
private void SimpleDirtyTracker_TextChanged(object sender, EventArgs e)
{
_isDirty = true;
}
private void SimpleDirtyTracker_CheckedChanged(object sender, EventArgs e)
{
_isDirty = true;
}
// recursive routine to inspect each control and assign handlers accordingly
private void AssignHandlersForControlCollection(
Control.ControlCollection coll)
{
foreach (Control c in coll)
{
if (c is TextBox)
(c as TextBox).TextChanged
+= new EventHandler(SimpleDirtyTracker_TextChanged);
if (c is CheckBox)
(c as CheckBox).CheckedChanged
+= new EventHandler(SimpleDirtyTracker_CheckedChanged);
// ... apply for other desired input types similarly ...
// recurively apply to inner collections
if (c.HasChildren)
AssignHandlersForControlCollection(c.Controls);
}
}
and in your mainform
public partial class Form1 : Form
{
private SimpleDirtyTracker _dirtyTracker;
private void Form1_Load(object sender, EventArgs e)
{
_dirtyTracker = new SimpleDirtyTracker(this);
_dirtyTracker.SetAsClean();
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
// upon closing, check if the form is dirty; if so, prompt
// to save changes
if (_dirtyTracker.IsDirty)
{
DialogResult result
= (MessageBox.Show(
"Would you like to save changes before closing?"
, "Save Changes"
, MessageBoxButtons.YesNoCancel
, MessageBoxIcon.Question));
}
}
If you want to save for example usersettings you could create Settings in your Properties.
You can get them like this:
string anyProperty = WindowsFormsApplication1.Properties.Settings.Default.TestSetting;
You save them using the Save-method:
WindowsFormsApplication1.Properties.Settings.Default.TestSetting = "Hello World";
WindowsFormsApplication1.Properties.Settings.Default.Save();
You can call the Save-method after you have clicked the close-button.
For saving several string properties you could create a property of the type System.Collections.Specialized.StringCollection, so that you just create one property and not 21.
One disadvantage of dirtytracer is, that it returns "dirty" even when changes revert to original state. If You use object in DataContext as Your data model, all this task simplifies to:
bool changed = dataContext.SomeTables.GetModifiedMembers(someRow).Any();
I have a form with 2 tabs on it. I can chose the tab viewed after initialization and I need some initial code every time after the tab2 is initialized:
public partial class SetupComponent : Form
{
public SetupComponent(bool tab2)
{
InitializeComponent();
if (tab2)
{
this.tabControl1.SelectedTab = tabPage2;
}
}
private void tabControl1_SelectedIndexChanged(object sender, EventArgs e)
{
textBox1.SelectionStart = textBox1.Text.Length;
textBox1.ScrollToCaret();
textBox2.SelectionStart = textBox2.Text.Length;
textBox2.Focus();
}
}
if I call this class with tab2=false and then click onto tab2, tabControl1_SelectedIndexChanged is called.
But if I select the tab2=true during SetupComponent, I find no possibility to do that code. All the TabControl1_Events I found are too early and I don`t find a matching TabPage2_Event.
How can I manage it?
I managed this problem using the Paint_Event:
bool activated = false;
private void tabPage2_Paint(object sender, PaintEventArgs e)
{
if (!activated)
{
tabControl1_SelectedIndexChanged(null, null);
activated = true;
}
}
I use the variable because the Paint_Event is called many times.
I am trying to create a notepad like application in C# by using a Textbox.
I want to implement find function in it. I want an ability to search the text entered in textbox of Find form in textbox of Form1 and then highlight it.
Please help i am unable to do it
Form1.cs
private void findToolStripMenuItem_Click(object sender, EventArgs e)
{
Find f = new Find();
f.Show();
}
public void find()
{
int idx = 0;
while((idx=textBox1.Text.IndexOf(text))!=1)
{
textBox1.Select();//Select the text which are found
}
}
Find.cs
public partial class Find : Form
{
Form1 f = new Form1();
public Find()
{
InitializeComponent();
}
private void Cancelbutton2_Click(object sender, EventArgs e)
{
this.Close();
}
private void Findbutton1_Click(object sender, EventArgs e)
{
f.text =textBox1.Text;
f.find();
}
You need to specify the start and length parameter in the "Select" method. For Example:
textBox1.Select(idx, text.Length);
You can only highlight one section of data at a time with the standard TextBox. Try FastColourTextbox if you want better support.
private void textBox1_Enter(object sender, System.EventArgs e){
if (!String.IsNullOrEmpty(textBox1.Text))
{
textBox1.SelectionStart = 0;
textBox1.SelectionLength = textBox1.Text.Length;
}
}
I'm trying to pass value from one form to another in winforms.
On my main form I have btnAddNewRecord and dataOptions combobox.
User should first select from combobox(dataOptions) and than click on btnAddNewRecord.
I want to pass this user selected value from dataoptions combobox to new form, so I tried like this
MainForm
private void btnAddNewRecord_Click(object sender, EventArgs e)
{
var formAddRecord = new FormNewRecord();
formAddRecord.ShowDialog();
}
private void Form1_Load()
{ populating combobox...}
private void dataOptions_SelectedIndexChanged(object sender, EventArgs e)
{
IMyCustomData data = (IMyCustomData)dataOptions.SelectedItem;
var formAddRecord = new FormNewRecord();
formAddRecord.SelectedDataOptions = data.ToString();
}
FormNewRecord.cs
public string SelectedDataOptions {get; set;}
private void FormNewRecord_Load(,,,,,)
{
txtSelectedDataOptions.Text = SelectedDataOptions;
}
no error on build, but on debugging txtSelectedDataOptions is not populated with passed value. What I'm doing wrong here?
Thanks
You are creating two different instances of FormNewRecord. Make formAddRecord as private field and show it on button click.
FormNewRecord formAddRecord = new FormNewRecord();
private void btnAddNewRecord_Click(object sender, EventArgs e)
{
formAddRecord.ShowDialog();
}
private void dataOptions_SelectedIndexChanged(object sender, EventArgs e)
{
IMyCustomData data = (IMyCustomData)dataOptions.SelectedItem;
formAddRecord.SelectedDataOptions = data.ToString();
}
Well, formAddRecord should be a private field of your class, not a var redeclared in each method !
(Method btnAddNewRecord_Click has no ideas of variables declared in Method dataOptions_SelectedIndexChanged, by the way you create different instances).
So
private FormNewRecord formNewRecord_ = new FormNewRecord();
private void btnAddNewRecord_Click(object sender, EventArgs e)
{
formNewRecord_ .ShowDialog();
}
private void Form1_Load()
{ populating combobox...}
private void dataOptions_SelectedIndexChanged(object sender, EventArgs e)
{
IMyCustomData data = (IMyCustomData)dataOptions.SelectedItem;
formNewRecord_.SelectedDataOptions = data.ToString();
}
I don't think new a form instance in another form is a good way, a better way you can set the data you want to pass as public in the parent form, and when you show the child form, set the parent form as child's owner, then you can get and use the data in the child form.
set the data as a public property in the parent form, like this: Main Form:
public string passData = "";
private void btnAddNewRecord_Click(object sender, EventArgs e)
{
var formAddRecord = new FormNewRecord();
formAddRecord.ShowDialog(this); //important
}
private void Form1_Load()
{ populating combobox...}
private void dataOptions_SelectedIndexChanged(object sender, EventArgs e)
{
IMyCustomData data = (IMyCustomData)dataOptions.SelectedItem;
passData = data.ToString(); //store the selected value to passData
}
2.get passed data from child's owner:
FormNewRecord.cs
private void FormNewRecord_Load(,,,,,)
{
if(this.Owner != null)
{
MainForm mf = (MainForm)this.Owner;
txtSelectedDataOptions.Text = mf.passData;
}
}