Please forgive me for such a stupid question. I am sure many of you will find this easy, where I have sent almost half the day reading trying to figure this out.
Here is the problem:
I have a FORM (Form1.cs) made. In that form I created a listview, and named it "ListView1".
Within the Form1.cs, I call a function called FileManager(this), where I pass in the THIS object.
In FileManager.cs I was able to listviewArray= originalForm.Controls.Find("listView1", true) and find that 'listview'.
When I do a listviewArray[0]<-- I can't seem to add a list to it.
FileManager.cs
FileManager(object sender)
{
if (sender != null)
{
originalForm = (Form)sender;
}
}
public void getFiles()
{
filePaths = Directory.GetFiles(hsocDir);
if(filePaths != null)
{
listviewArray= originalForm.Controls.Find("listView1", true);
if(listviewArray != null)
{
ListViewItem lvi = new ListViewItem("text");
// My Array is listViewArray
// How to add things to Lvi to it.
}
}
== Form1.cs
public Form1()
{
InitializeComponent(`enter code here`);
mysql = new MySQLCheck(this);
fileManager = new FileManager(this);
fileManager.getFiles();
}
You can't access element 0 of the collection because the collection is empty. To add an item, use:
listViewArray.Items.Add(lvi);
You need to modify the Items collection instead of the ListView itself for this to work, as ListView is not a collection (its a control).
listViewArray.Items.Add(lvi);
Also in your listview,setting this properties will help :
// Set the view to show details.
listViewArray.View = View.Details;
// Select the item and subitems when selection is made.
listViewArray.FullRowSelect = true;
// Display grid lines.
listViewArray.GridLines = true;
Related
I'm having a bit of a weird problem where I am trying to update the checked status of a checkbox contained inside a ListBoxItem, I am unable to get a ListBoxItem after the 7th item I've tried several methods to get this to work, as seen in the below method. itemIndex each time does have a positive value (so the I know the item is being found), but why It cant get the listboxitem I do not know
private IEnumerable<CheckBox> GetListBoxItemCheckBoxes(object item)
{
var itemIndex = LstItems.Items.IndexOf(item);
var selectedListBoxItem = LstItems.ItemContainerGenerator.ContainerFromIndex(itemIndex) as ListBoxItem;
var selectedListBoxItemCheckBoxes = selectedListBoxItem?.FindVisualChildrenOfType<CheckBox>();
if (selectedListBoxItemCheckBoxes == null)
{
selectedListBoxItem = LstItems.ItemContainerGenerator.ContainerFromItem(item) as ListBoxItem;
selectedListBoxItemCheckBoxes = selectedListBoxItem?.FindVisualChildrenOfType<CheckBox>();
if (selectedListBoxItemCheckBoxes == null)
{
itemIndex = LstItems.ItemContainerGenerator.Items.IndexOf(item);
selectedListBoxItem = LstItems.ItemContainerGenerator.ContainerFromIndex(itemIndex) as ListBoxItem;
selectedListBoxItemCheckBoxes = selectedListBoxItem?.FindVisualChildrenOfType<CheckBox>();
}
}
return selectedListBoxItemCheckBoxes;
}
I think that this may be to do with the timing of when I am trying to set the checkbox states as I am trying to do it after I have added that item? I've read a few questions relating to this area on SO but so far none of have been able to help me with my problem, I thought this answer might be close.. but It gave me the same result: https://stackoverflow.com/a/23501378/1800140
The items are not bound, they are added using ListBox.Items.Add (not too familiar with binding).
I am also doing this in a background thread as I need to refresh the contents of my listbox regularly and need to make an api call to do so.
The method that is being used for updating the contents of my listbox is as below. SetItemChecked calls the first method to get the checkbox, however this starts to return null after the 7th item
public void ResetAndAddItems<T>(IEnumerable<T> items, string displayByProperty = "",
Func<T, string> displayByFunc = null,
Dictionary<string, bool> checkedStates = null,
Func<ListItem<T>, Dictionary<string, bool>, bool> checkedStatesKeyFunc = null)
{
Dispatcher.Invoke(() =>
{
LstItems.Items.Clear();
});
var listedItems = items?.ToList();
if (listedItems == null || !listedItems.Any())
{
return;
}
foreach (var item in listedItems)
{
var listItem = new ListItem<T>
{
DisplayByProperty = displayByProperty,
DisplayByFunc = displayByFunc,
Item = item
};
Dispatcher.Invoke(() =>
{
LstItems.Items.Add(listItem);
if (checkedStates != null && checkedStatesKeyFunc != null)
{
SetItemChecked(item, checkedStatesKeyFunc(item as ListItem<T>, checkedStates));
}
});
}
}
UI Virtualization is set to True by default on ListBoxes. And if UI Virtualization is enabled, containers will only be created for the visible items. Try setting this attached property:
VirtualizingStackPanel.IsVirtualizing="False"
To fix this issue, I had to result to binding.
The issue is that because only 7 items are display on the listview at once only 7 items are drawn, to get around this I can scroll to the next item after the 7th item and so on however this was noticeably slower.
I need to access a grid in a list-view data-template, but when using this code the program reaches the foreach loop and don't execute it
foreach (Grid firstgrid in Active_list.Items)
{
var item = Active_list.ItemContainerGenerator.ContainerFromItem(firstgrid);
var ch = AllChildren(item);
var tag = url;
var control = (Grid)ch.First(c => c.Tag == tag);
if (firstgrid.GetType() == typeof(Grid))
{
if ((String)firstgrid.Tag == url)
{
foreach (ProgressBar prg in firstgrid.Children)
{
if (prg.GetType() == typeof(ProgressBar))
{
prg.IsIndeterminate = false;
}
}
foreach (TextBlock txt in firstgrid.Children)
{
if (txt.GetType() == typeof(TextBlock))
{
txt.Visibility = Visibility.Visible;
}
}
}
}
}
This code Active_list.Items won't give you any control but your actual data. If you want to access specific control in you list view, you need to go through your visual tree and find it manually. I think it's not a good practice to manually change controls inside list view...
But if you really want to do it this way I recommend you to check out this topic with similar question: How to access a specific item in a Listbox with DataTemplate?
I have a BindingList< KeyValuePair < string, string > > that is bound to a ComboBox control. Based on some conditions, the BindingList will be added a new KeyValuePair. Now, the Newly added item shows up at index 0 of the Combobox, instead of at the end.
While debugging, I found that the BindingList has got the right order. (i.e, the new KeyValuePair is appended)
Also, I check the SelectedValue of the ComboBox in it's SelectedIndexChanged handler and it seems to be not of the ListItem that got selected. Instead, it is that of the supposed ListItem, if the ComboBox had got the right order as in its DataSource, - the BindingList..
The code is a small part of a large project.. Plz let me know if the question is not clear. I can put the relevant parts of the code as per our context.
How could something like this happen? What can I do differently?
I have this class something like this.
public class DropdownEntity
{
//removed all except one members and properties
private string frontEndName
public string FrontEndName
{
get {return this.frontEndName; }
set {this.frontEndName= value; }
}
//One Constructor
public DropdownEntity(string _frontEndName)
{
this.FrontEndName = _frontEndName;
//Removed code which initializes several members...
}
//All methods removed..
public override string ToString()
{
return frontEndName;
}
}
In my windows form, I have a tab control with several tabs. In one of the tabs pages, I have a DataGridView. The user is supposed to edit the cells and click on a Next - button. Then, some processing will be done, and the TabControl will be navigated to the next tab page.
The next tab page has the combobox that has the problem I mentioned. This page also has a back button, which will take back.. the user can modify the gridview cells again.. and click on the next button. This is when the order gets messed up.
I am posting here the Click event handler of the Next Button.. Along with the class, with the rest of the code removed.
public partial class AddUpdateWizard : Form
{
//Removed all members..
BindingList<KeyValuePair<string, string>> DropdownsCollection;
Dictionary<string, DropdownEntity> DropdownsDict;
//Defined in a partial definition of the class..
DataGridView SPInsertGridView = new DataGridView();
ComboBox DropdownsCmbBox = new ComboBox();
Button NextBtn2 = new Button();
Button BackBtn3 = new Button();
//Of course these controls are added to one of the panels
public AddUpdateWizard(MainForm mainForm)
{
InitializeComponent();
DropdownsDict = new Dictionary<string, DropdownEntity>();
}
private void NextBtn2_Click(object sender, EventArgs e)
{
string sqlArgName;
string frontEndName;
string fieldType;
for (int i = 0; i < SPInsertGridView.Rows.Count; i++)
{
sqlArgName = "";
frontEndName = "";
fieldType = "";
sqlArgName = SPInsertGridView.Rows[i].Cells["InsertArgName"].Value.ToString().Trim();
if (SPInsertGridView.Rows[i].Cells["InsertArgFrontEndName"].Value != null)
{
frontEndName = SPInsertGridView.Rows[i].Cells["InsertArgFrontEndName"].Value.ToString().Trim();
}
if (SPInsertGridView.Rows[i].Cells["InsertArgFieldType"].Value != null)
{
fieldType = SPInsertGridView.Rows[i].Cells["InsertArgFieldType"].Value.ToString().Trim();
}
//I could have used an enum here, but this is better.. for many reasons.
if (fieldType == "DROPDOWN")
{
if (!DropdownsDict.ContainsKey(sqlArgName))
DropdownsDict.Add(sqlArgName, new DropdownEntity(frontEndName));
else
DropdownsDict[sqlArgName].FrontEndName = frontEndName;
}
else
{
if (fieldType == "NONE")
nonFieldCount++;
if (DropdownsDict.ContainsKey(sqlArgName))
{
DropdownsDict.Remove(sqlArgName);
}
}
}
//DropdownsCollection is a BindingList<KeyValuePair<string, string>>.
//key in the BindingList KeyValuePair will be that of the dictionary.
//The value will be from the ToString() function of the object in the Dictionary.
DropdownsCollection = new BindingList<KeyValuePair<string,string>>(DropdownsDict.Select(kvp => new KeyValuePair<string, string>(kvp.Key, kvp.Value.ToString())).ToList());
DropdownsCmbBox.DataSource = DropdownsCollection;
DropdownsCmbBox.DisplayMember = "Value";
DropdownsCmbBox.ValueMember = "Key";
//Go to the next tab
hiddenVirtualTabs1.SelectedIndex++;
}
private void BackBtn3_Click(object sender, EventArgs e)
{
hiddenVirtualTabs1.SelectedIndex--;
}
//On Selected Index Changed of the mentioned Combobox..
private void DropdownsCmbBox_SelectedIndexChanged(object sender, EventArgs e)
{
if (DropdownsCmbBox.SelectedValue != null)
{
if (DropdownsDict.ContainsKey((DropdownsCmbBox.SelectedValue.ToString())))
{
var dropdownEntity = DropdownsDict[DropdownsCmbBox.SelectedValue.ToString()];
DropdownEntityGB.Text = "Populate Dropdowns - " + dropdownEntity.ToString();
//Rest of the code here..
//I see that the Datasource of this ComboBox has got the items in the right order.
// The Combobox's SelectedValue is not that of the selected item. Very Strange behavior!!
}
}
}
}
The very first time the user clicks the Next Button, it's fine. But if he clicks the Back Button again and changes the Data Grid View cells.. The order will be gone.
I know, it can be frustrating to look at. It's a huge thing to ask for help. Any help would be greatly appreciated!
Please let me know if you need elaboration at any part.
Thanks a lot :)
I think you have two problems here.
First, if you want to retain the order of the items you should use an OrderedDictionary instead of a regular one. A normal collection will not retain the order of the items when you use Remove method. You can see more info about this related to List here.
You could use such dictionary like this:
DropDownDict = new OrderedDictionary();
// Add method will work as expected (as you have it now)
// Below you have to cast it before using Select
DropDownCollection = new BindingList<KeyValuePair<string, string>>(DropDownDict.Cast<DictionaryEntry>().Select(kvp => new KeyValuePair<string, string>(kvp.Key.ToString(), kvp.Value.ToString())).ToList());
The second problem could be that you change the display name (FrontEndName) of already existing items, but the key is preserved. When you add a new item, try to remove the old one that you're not using anymore and add a new item.
The Sorted Property of the Combobox is set to True! I didn't check that until now. I messed up. Terribly sorry for wasting your time Adrian. Thanks a lot for putting up with my mess here.. :)
I have a method that adds items to my listbox called refreshInterface which is called as soon as the programe starts, adding names of homeforms in the listbox using the FormItems class, here is the rereshInterface method below
public void refreshInterface()
{
//int number = 0;
foreach (DataSet1.xspGetAnalysisUsageTypesRow homeForms in myDataSet.xspGetAnalysisUsageTypes)
{
var forms = new FormItems(homeForms);
listBox1.Items.Add(forms);
}
}
The FormItems class is this below
public class FormItems
{
public DataSet1.xspGetAnalysisUsageTypesRow types { get; set; }
public FormItems(DataSet1.xspGetAnalysisUsageTypesRow usageTypes)
{
types = usageTypes;
}
public override string ToString()
{
// returns the rows that are relating to types.xlib_ID
var libtyps = types.GetxAnalysisUsageRows();
var cnt = 0;
foreach (DataSet1.xAnalysisUsageRow ty in libtyps)
{
//returns true if ty is null
bool typeNull = ty.Isxanu_DefaultNull();
// if its false, if xanu_Default is set
if (!typeNull)
{
cnt += 1;
}
}
var ret = String.Format("set {0} [Set: {1}]", types.xlib_Desc, cnt);
//return this.types.xlib_Desc;
return ret;
}
}
Each listbox (the listbox is on the left of the homeform) item has a number of reports that can be added to it, so for instance, i select an homeform from my listbox, there are 12 textboxes on the right hand side and each textbox has a pair of buttons which are Browse and Clear. If I click on the browse button a new form appears, and i select a report from that form and add it to a particular textbox, the count for that homeform should update, and i clear a textbox for a particular homeform, the count should also update.
At the moment when i debug the application, it shows me the count of each Homeform depending on the amount of reports added to the homeform, but while the programe is running, if i add a new report to a homeform, the count does not update until i restart the debug session. I was told about using a Databinding method but not sure of how i could use it here
How do i ge my listbox item to update ?
You should probably look into binding. Here is a good place to start:
http://www.codeproject.com/Articles/140621/WPF-Tutorial-Concept-Binding
If you want a GUI to respond to data changes then binding is your best friend.
You should bind List Box component source to Observable Collection, every update you do to Observable Collection will update List Box data.
Might not be exact but should give you an idea.
public void refreshInterface()
{
Dictionary<int,string> items = new Dictionary<int,string>();
//int number = 0;
foreach (DataSet1.xspGetAnalysisUsageTypesRow homeForms in myDataSet.xspGetAnalysisUsageTypes)
{
var formitem = new FormItems(homeForms);
items.Add(formitem.someprop, formitem.toString());
}
listbox.DataSource = items;
listbox.DisplayMember = "Value";
listbox.ValueMember = "Key";
}
Is it possible to animate ListView items in C# ? The purpose is that I have a ListView that is asynchronously modified, and I'd like to animate smoothly the items that have been modified, until the user clicks them. This way items blinking, or whatever would do the trick, are the items that changed which haven't been reviewed yet.
Thank you guys !
UPDATE : sorry, i forgot. Never used WPF before, and I think it's too late to switch to it now. I'm using winforms.
I had to do something similar to what you are trying to do but instead of animating the ListView, I used custom checkbox layout in the list view to look different. The designer code for the ListView looks like:
this.listView1.HeaderStyle = System.Windows.Forms.ColumnHeaderStyle.None;
this.listView1.Location = new System.Drawing.Point(104, 90);
this.listView1.MultiSelect = false;
this.listView1.Name = "listView1";
this.listView1.Size = new System.Drawing.Size(264, 105);
this.listView1.Sorting = System.Windows.Forms.SortOrder.Ascending;
this.listView1.TabIndex = 7;
this.listView1.UseCompatibleStateImageBehavior = false;
this.listView1.View = System.Windows.Forms.View.Details;
this.listView1.MouseClick += new System.Windows.Forms.MouseEventHandler(this.listView1_MouseClick);
Then I declared a list that will hold the selection of the user.
private IList<ListViewItem> m_CheckedItems = new List<ListViewItem>();
Here is the initialise method for the ListView. You need to manipulate here for the initial look of your listview.
private void InitialiseListView(IList<string> data)
{
listView1.Items.Clear();
m_CheckedItems.Clear();
listView1.Columns.Clear();
listView1.Columns.Add("Col1");
listView1.Columns[0].Width = listView1.Width;
ListView.ListViewItemCollection collection = new ListView.ListViewItemCollection(listView1);
ImageList images = new ImageList();
images.Images.Add(global::MyApplication.Properties.Resources.Checkbox_Unchecked);
images.Images.Add(global::MyApplication.Properties.Resources.Checkbox_Checked);
listView1.SmallImageList = images;
foreach (string str in data)
{
ListViewItem item = new ListViewItem();
item.ImageIndex = 0;
item.Text = str;
collection.Add(item);
}
}
This event triggers when the user selects an option in the list view. The selection is recorded in the list I created above and the checked image is displayed so that it looks like the user has selected the item.
private void listView1_MouseClick(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left && listView1.FocusedItem != null)
{
if (listView1.FocusedItem.ImageIndex == 1)
{
listView1.FocusedItem.ImageIndex = 0;
m_CheckedItems.Remove(listView1.FocusedItem);
}
else
{
listView1.FocusedItem.ImageIndex = 1;
m_CheckedItems.Add(listView1.FocusedItem);
}
}
}
You can probably fiddle with fonts and forecolor of these items ... Each item within a List View is of type ListViewItem so you can individually manipulate it.
Hope this gives you some direction :)
You could use a MyListView: ListView and override OnDrawSubItem. Have the e.Item.Tag to store the "Clicked" state and update the background according to its state.
public partial class ObjectListView : ListView {
(....)
protected override void OnDrawSubItem(DrawListViewSubItemEventArgs e)
{
if(bool)e.Item.Tag)
(...) animate
}
You can do that easier in WPF.
WPF Basic
http://msdn.microsoft.com/en-us/library/ms754130.aspx
http://en.wikipedia.org/wiki/Windows_Presentation_Foundation
WPF Animation
http://msdn.microsoft.com/en-us/library/ms752312.aspx
ListView animation sample
(WPF) Animate ListView item move
WPF ListView animation by reorder of items?