C# editable listview - c#

Yesterday I try to implement a new listview that support sub-item edit, my solution is to show a textbox when double click the sub-item. The key code as following:
protected override void OnDoubleClick(EventArgs e)
{
Point pt = this.PointToClient(Cursor.Position);
ListViewItem curItem;
int subItemIndex = GetSubItemAt(pt.X, pt.Y, out curItem);
DoubleClickEventArgs args = new DoubleClickEventArgs(subItemIndex);
base.OnDoubleClick(args);
if (subItemIndex>=0 && !args.Cancel)
{
//StartEdit(...);
}
}
public void EndEdit(bool acceptChanges)
{
//validation
.................
.................
AfterSubItemEventArgs e = new AfterSubItemEventArgs(this.SelectedItems[0], m_editSubItemIndex, this.SelectedItems[0].SubItems[m_editSubItemIndex].Text, m_textbox.Text, false);
OnAfterSubItemEdit(e);
if (e.Cancel)
{
//....
}
else
{
//set new value
}
m_textbox.Visible = false;
m_editSubItemIndex = -1;
}
OnAfterSubItemEdit is a event that user can do some validations or other operations. I add a check in this method, if the new value exist, I will show a messagebox to user firstly, then hide the textbox. But now, the problem comes, when i move the mouse, the listview items can be selected, I don't how to solve this issue, I tried my best to find out the way, but failed. So, please help me!

Listview has a LabelEdit property; when you set it "true", then in an event handler you can call Listview.Items[x].BeginEdit(), and edit an item. As an example, you can handle ListView.DoubleClick event and call BeginEdit right there:
private void Form1_Load(object sender, System.EventArgs e)
{
listView1.LabelEdit = true;
}
private void listView1_DoubleClick(object sender, System.EventArgs e)
{
if(this.listView1.SelectedItems.Count==1)
{
this.listView1.SelectedItems[0].BeginEdit();
}
}

The problem is that your form still calls the DoubleClick event whether the value exists or not. Add appropriate condition before calling base DoubleClick in your code, i.e.:
if(!new value exists)
base.OnDoubleClick(args);

Related

Is it possible to tell if the Text change on an entry was from code or from the UI?

I am working on a Xamarin project and I need to be able to tell if the changes that occur to the text in an Entry view are from the code or from the UI, is this possible in Xamarin? or is there a known work around to do this.
I know about the OnTextChanged event but this only tells you that the Text property has changed, and gives you access to the old and new value of the Text property. It does not differentiate between different causes of text change.
You can get some idea from this thread, check if the entry is focused to differentiate between different causes of text change:
public MainPage()
{
InitializeComponent();
myEntry.TextChanged += MyEntry_TextChanged;
}
private void MyEntry_TextChanged(object sender, TextChangedEventArgs e)
{
var entry = sender as Entry;
if (entry.IsFocused)
{
//change from UI
Console.WriteLine("change from UI");
}
else{
//change from code
Console.WriteLine("change from code");
}
}
Update: The better way to solve op's problem:
You can set a flag yourself that tells your code to ignore the event. For example:
private bool ignoreTextChanged;
private void textNazwa_TextCanged(object sender, EventArgs e)
{
if (ignoreTextChanged) return;
}
Create a method and use this to set the text instead of just calling Text = "...";::
private void SetTextBoxText(TextBox box, string text)
{
ignoreTextChanged = true;
box.Text = text;
ignoreTextChanged = false;
}
Refer: ignoreTextChanged
you can use EntryRenderer to detect keypress event and use that flag to detect the change by code or by UI.
Here are the step:
- Exetend your entry control with new event OnTextChangeByUI
- Write custom render for both platform
e.g for android it will be something like this
public class ExtendedEntryRender : EntryRenderer
{
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if (Control != null)
{
Control.KeyPress += ((Entry)Element).OnTextChangeByUI;
}
}
}

Selected index changed fail into ListBox

I created a windows forms like this
As you can see in selected changed event I disable button move to, it works correctly, problem starts when I try to
return an item it to main list, move to button keeps disable instead enable it again when I select item of first list. Someone knows
what occurs there?
Events:
private void lstTechUnnotified_SelectedIndexChanged(object sender, EventArgs e)
{
btnReturnTo.Enabled = false;
btnMoveTo.Enabled = true;
}
private void lstTechToNotified_SelectedIndexChanged(object sender, EventArgs e)
{
btnReturnTo.Enabled = true;
btnMoveTo.Enabled = false;
}
You need to make sure that there actually is an item being selected since ListBox.SelectedIndexChanged event gets fired even when there're no items selected - making the new SelectedIndex equal to -1. Also, from the way you asking, I expect you want to enable btnMoveTo when there's a selected item in lstTechUnnotified and otherwise, disable it - and the same for btnReturnTo and lstTechToNotified; if that's it, then the easy way is:
private void lstTechUnnotified_SelectedIndexChanged(object sender, EventArgs e)
{
btnMoveTo.Enabled = (lstTechUnnotified.SelectedIndex > -1);
}
private void lstTechToNotified_SelectedIndexChanged(object sender, EventArgs e)
{
btnReturnTo.Enabled = (lstTechToNotified.SelectedIndex > -1);
}
Though I'm not sure about your button names..

Winforms C# Disable/ Enable Button on Treenode Click

I have a treenode which displays a checklist from a SQL database. I have a method to get the selected workflows.
I want to enable the run button if a checkbox is checked and disable the button if nothing is checked and on load.
I'm not sure where to put this if statement. I have tried putting it under the run button on the click action but it is not working correctly.
Any help is appreciated.
List<WorkflowViewModel> workflowViewList = new List<WorkflowViewModel();
var workflowList = GetSelectedWrokflows();
if (workflowList.Count == 0)
{
button.enabled = false;
}
else
{
button.enabled = true;
}
One way to do this is to create a method that will do the work of determining the selected workflow items and enabling or disabling the button. By putting the code in a single method, it allows you to call it from multiple places, and if you need to change the behavior, you only have one place to make the modifications.
Then you can just call this method from the Form_Load event, and from the checked list box's ItemCheck event:
public partial class Form1 : Form
{
List<WorkflowViewModel> workflowViewList = new List<WorkflowViewModel>();
private void SetRunButtonState()
{
workflowViewList = GetSelectedWorkflows();
button.Enabled = workflowViewList.Count > 0;
}
private void Form1_Load(object sender, EventArgs e)
{
SetRunButtonState();
}
private void treeView1_AfterCheck(object sender, TreeViewEventArgs e)
{
SetRunButtonState();
}
// Rest of class code omitted...
}

ObjectListView drag and drop to RichTextBox

So I have an objectlistview (actually a treelistview). I want to be able to drag an item from this onto a richtextbox, and have it insert a property of the dragged item (in this case Default_Heirarchy_ID)
The TreeListView's objectmodel is a List<T> of a class called SpecItem.
This is what I have so far:
public frmAutospecEditor(SpecItem siThis_, List<SpecItem> lstStock_)
{
InitializeComponent();
txtFormula.DragEnter += new DragEventHandler(txtFormula_DragEnter);
txtFormula.DragDrop += new DragEventHandler(txtFormula_DragDrop);
...
}
void txtFormula_DragEnter(object sender, DragEventArgs e)
{
e.Effect = DragDropEffects.Copy;
}
private void tlvSpecItem_ItemDrag(object sender, ItemDragEventArgs e)
{
int intID = ((SpecItem)tlvSpecItem.GetItem(tlvSpecItem.SelectedIndex).RowObject).Default_Heirarchy_ID ??0;
DoDragDrop(intID, DragDropEffects.Copy);
}
private void txtFormula_DragDrop(object sender, System.Windows.Forms.DragEventArgs e)
{
object objID = e.Data.GetData(typeof(String));
//this is where it goes wrong - no matter what I try to do with this, it
//always returns either null, or the text displayed for that item in the TreeListView,
//NOT the ID as I want it to.
string strID = (string)objID;
txtFormula.Text = strID;
}
Where am I going wrong?
Cheers
The Drag is the control you want to take data from (your OLV).
The Drop is the destination control (your textbox). So:
Set the IsSimpleDragSource property of your OLV to true.
In the textbox set AllowDrop property to true. Then handle the DragEnter event of your textbox and use the DragEventArgs param.
Handle the ModelDropped event:
private void yourOlv_ModelDropped(object sender, ModelDropEventArgs e)
{
// If they didn't drop on anything, then don't do anything
if (e.TargetModel == null) return;
// Use the dropped data:
// ((SpecItem)e.TargetModel)
// foreach (SpecItem si in e.SourceModels) ...
// e.RefreshObjects();
}
Read more: http://objectlistview.sourceforge.net/cs/dragdrop.html#ixzz1lEt7LoGr

Determine source of event

I have a dropdown list and radio button. If something is selected from the dropdown by the user, I want the radio button cleared. If the radio button is selected I want the selection of the dropdown cleared. Unfortunately, this creates events that cancel each other out. I tried using the sender as shown below to determine if the value was being changed by code or by the user, but that doesn't work. How do I make these events only work if the user is the source of the action?
private void rbBlank_Checked(object sender, RoutedEventArgs e)
{
// Verify source of event
if (sender is RadioButton)
{
// Display
comboBoxTitles.SelectedIndex = -1;
}
}
private void comboBoxTitles_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
{
// Verify source of event
if (sender is ComboBox)
{
// Display
rbBlank.IsChecked = false;
}
}
You won't be able to tell the difference between the two since the source will be the same instance for both occasions.
This doesn't answer the question directly but if you compare the SelectedIndex of comboBoxTitles in the SelectionChanged event handler, your problem should be solved
private void comboBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (comboBoxTitles.SelectedIndex != -1)
{
rbBlank.IsChecked = false;
}
}
Try to compare if sender == instance of a control instead of is type of.
private void rbBlank_Checked(object sender, RoutedEventArgs e)
{
// Verify source of event
if (sender == rbBlank)
{
// Display
comboBoxTitles.SelectedIndex = -1;
}
}
private void comboBoxTitles_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
{
// Verify source of event
if (sender == comboBoxTitles)
{
// Display
rbBlank.IsChecked = false;
}
}
If you know the IDs of those controls, you can try something like this:
System.Web.UI.WebControls.WebControl webControl = (System.Web.UI.WebControls.WebControl) sender;
if( webControl.ID == <comboboxId>)
{
//Do something
}
I havent tried this, but I guess it might work.

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