using Silverlight & Prism.
i create a new scoped region inside a TabControl like so:
IRegionManager regionManager = tabControl.Add(viewRegions, UNIQUEID, true);
then from the TabControl SelectionChanged event i want to get the name of that region.
so i go:
TabItem item = e.AddedItems[0] as TabItem;
FrameworkElement view = item.Content as FrameworkElement;
IRegionManager xxx = RegionManager.GetRegionManager(view);
so now i have the scoped region manager at hand = xxx!
but how do i get its name? (the "UNIQUEID" param i have assigned to it ).
HOW?
If you have the RegionManager, and the View, then you can get the region Name (but I don't know why you'd ever want to). If you loop through the regionmanger like this you can get what you want. You'll have to keep a reference around to the scoped RegionManager, but there's no way around that. (There is some extra code demonstrating other things that someone might want to do too)
private void UnloadRegion()
{
foreach (IRegion region in xxx.Regions)
{
for (int ix = region.ActiveViews.Count() - 1; ix >= 0; ix--)
{
if (WhateverYourCurrentViewIs == region.ActiveViews.Last())
{
string RegionName = region.Name;
//there is the name
{
}
}
}
Related
I have a Custom control inheriting from Control class in my WinForm. My control contains multiple panels and other UIElements.
This is what my control is supposed to look like
There's a database panel,
database panel contains a single checkbox only.
and there's a Server panel,
server panel contains many database panels and a single label; the header label.
And finally there's the container panel that contains all my Server panels.
I found this Item Collection option for a User Control but I couldn't really understand the accepted answer on it. If someone could help explain it better that would be great.
Also, if someone could just put some links for creating advanced custom controls. I've been reading all day about it and I still can't make any sense of it all. Is there a step-by-step guide for advanced custom controls?
[Edit]
Basically what I need is to create a custom collection within my custom control. Currently my control is built as Winform Control Library which I build and then I use in my main program later.
So in my main program, I can just drag and drop the component on my form and use it.
By default, the custom control will load with one Server that contains one database.
What I want is to be able to add/remove other databases/servers to it if I need to, in my MAIN program
I'm having trouble explaining exactly what I need because I simply do not understand how the whole custom control/items collection thing works really, and i'm sorry for that. I would really appreciate some links that explains this stuff clearly
here's my code for this control:
This code only creates my default control, but I am UNABLE to add to it. The collection property appears in my property windows but when I add items to it and click okay nothing happens.
public class Database : System.Windows.Forms.Panel
{
public CheckBox _ckbDatabase;
public Database()
{
_ckbDatabase = new CheckBox();
this.BackColor = _pnlDatabaseBackColor;
this.Size = _pnlDatabaseSize;
this.AutoSize = false;
this.Height = 40;
this.Width = 200;
this.Location = _pnlDatabaseLocation;
_ckbDatabase.Top = 10;
_ckbDatabase.Left = 15;
_ckbDatabase.TextAlign = _ckbdbTextAlignment;
_ckbDatabase.Font = _ckbdbFont;
_ckbDatabase.ForeColor = Color.White;
this.Controls.Add(_ckbDatabase);
}
#Propterties
}
public class Server : System.Windows.Forms.Panel
{
private Label _lblserver;
private Database database;
public Server()
{
_lblserver = new Label();
database = new Database();
this.BackColor = _pnlServerBackColor;
this.Size = _pnlServerSize;
this.AutoSize = false;
_lblserver.Dock = _lblserverDock;
_lblserver.Font = _lblsrvFont;
_lblserver.BackColor = _lblServerBackColor;
_lblserver.AutoSize = false;
_lblserver.Text = SRV;
database.Top = 35;
database._ckbDatabase.Text = DB;
this.Controls.Add(_lblserver);
this.Controls.Add(database);
}
[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
public DatabaseCollection DatabaseCollection { get; set; }
#Propterties
}
public class ServersCollection : CollectionBase
{
public Server this[int index]
{
get { return (Server)List[index]; }
}
public void Add(Server server)
{
List.Add(server);
}
public void Remove(Server server)
{
List.Remove(server);
}
}
How about something simple like this:
public class Server {
public string Name { get; set; }
public List<Database> Databases { get; set; }
public Server() {
Databases = new List<Database>();
}
}
public class Database {
public string Name { get; set; }
public bool Enabled { get; set; }
}
Then you can just add it like this:
List<Server> servers = new List<Server>();
Server serverA = new Server { Name = "Server A" };
serverA.Databases.Add(new Database { Name = "Database 1", Enabled = true });
serverA.Databases.Add(new Database { Name = "Database 2", Enabled = false });
Server serverB = new Server { Name = "Server B" };
serverB.Databases.Add(new Database { Name = "Database 1", Enabled = false });
serverB.Databases.Add(new Database { Name = "Database 2", Enabled = false });
servers.Add(serverA);
servers.Add(serverB);
When you link to the Item Collection part it seemed like you wanted to be able to add servers and databases in design mode but then you mention you want to do it by code? If this is not what you want you need to give us more information.
Looks to me like you are mostly there. First off, here's a more complete collection class:
public class ServersCollection : IEnumerable<Server>
{
private List<Server> _servers = new List<Server>();
public Server this[int index]
{
get { return _servers[index]; }
}
public IEnumerator<Server> GetEnumerator()
{
foreach (var server in _servers)
yield return server;
}
IEnumerator IEnumerable.GetEnumerator() { return GetEnumerator(); }
public void Add(Server server)
{
_servers.Add(server);
}
public void Remove(Server server)
{
//You might consider a deliberate loop to evaluate a proper match
//Don't forget to Dispose() it first!
_servers.Remove(server);
}
public void Clear()
{
for (Int32 i = _servers.Count - 1; i >= 0; i--)
_servers[i].Dispose();
_servers.Clear();
}
}
Add an instance of the ServersCollection class to the container control, the one at the top level that holds server panels:
private ServersCollection _servers = new ServersCollection();
public ServersCollection Servers { get { return _servers; } }
Use that as a way for it to add Server controls to its own collection of controls.
Do a similar thing with the DatabaseCollection in the Server class, again so that it can add Database panels to its controls collection.
Then, wherever you have an instance of a control, you will also have access to the collection of what it holds:
myControl.Servers
//-or-
myServer.Databases
...allowing you to add/remove, as such:
myControl.Servers.Add(new Server());
//-or-
myServer.Databases.Add(new Database());
Points of emphasis
Your classes are controls, but they also own other controls. Proper use of the Dispose pattern will be crucial or you'll have memory issues throughout.
I would remove these lines, they don't matter unless you intend to add servers/DBs at form design time (i.e. fixed entries or defaults):
[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
public DatabaseCollection DatabaseCollection { get; set; }
Finally, you could (should!) take that collection class further, with overloads for Add() and Remove() that do a better job of deciding when/how/what to do based on more than an instance, e.g. by name? You could also add another indexer to fetch by name, for instance, instead of just index (which you might not readily know).
Im busy with my app and i walked in some problems when i click on a photo in my listbox PhotoFeed.
I got 1 List<> with in it the strings UrlTumb and UrlFull.
I got 1 ListBox with in it a WrapPanel filled with images wich i set the Image.Source from my UrlTumb.
What my problem is when i click on a photo in my listbox i want to navigate to a new page and display there the original image (UrlFull) now i can only get my UrlTumb from my Image.Source but i want my UrlFull which is stored in the List. Now is my question how do i obtain the UrlFull. So how can i back trace which item i clicked and get the UrlFull from that item so i can send it with my NavigationService.Navigate
I can do it on an dirty way and create an invisible textblock besides the image in my ListBox and put the UrlFull in there but i would like to do it in a proper way
So what do i place in the ????? spot in this line
NavigationService.Navigate(new Uri("/PhotoInfo.xaml?urlfull={0}", ????? , UriKind.Relative));
Greetings Cn
There are multiple options:
Use selected item's index listBox.SelectedIndex to get the index
of the selected property which will correspond to the index in your
source (it might not if you filter the collection using collection
source, but I think that is not the case)
Use selected item listBox.SelectedItem this will return the
SelectedItem which will contain your object. (Note, that if your
selection mode set to multiple, this will return only the firstly
selected item)
Use SelectemItems. It will allow you to get an array of selected
items (Note: this should be normally used only when your list's
selection mode is set to multiple)
Use SelectedValue, which will contain the value of the SelectedItem
(this will save you and extra step.
Use arguments of the Selection changed event AddedItems.
Bellow is the code snippet of 3 options above. x, y, z will all be your selected names (e.g. "Mike")
XAML:
<ListBox x:Name="lb"
ItemsSource="{Binding Names}"
SelectionChanged="NameChanged" />
Code behind:
public class Person
{
public string Name { get; set; }
public override string ToString()
{
return Name;
}
}
private List<Person> people = new List<Person>
{
new Person{Name = "Lewis"},
new Person{Name = "Peter"},
new Person{Name = "Brian"}
};
public List<Person> People
{
get
{
return this.people;
}
set
{
this.people = value;
}
}
private void NameChanged(object sender, SelectionChangedEventArgs e)
{
var x = this.people[lb.SelectedIndex];
var y = lb.SelectedItem;
var z = lb.SelectedItems[0];
var h = lb.SelectedValue;
var u = e.AddedItems[0];
var person = e.AddedItems[0] as Person;
if (person != null)
{
var result = person.Name;
}
}
For the differences between SelectedValue and SelectedItem refer here SelectedItem vs SelectedValue
This really seems like a bug to me, but perhaps some databinding gurus can enlighten me? (My WinForms databinding knowledge is quite limited.)
I have a ComboBox bound to a sorted DataView. When the properties of the items in the DataView change such that items are resorted, the SelectedItem in my ComboBox does not keep in-sync. It seems to point to someplace completely random. Is this a bug, or am I missing something in my databinding?
Here is a sample application that reproduces the problem. All you need is a Button and a ComboBox:
public partial class Form1 : Form
{
private DataTable myData;
public Form1()
{
this.InitializeComponent();
this.myData = new DataTable();
this.myData.Columns.Add("ID", typeof(int));
this.myData.Columns.Add("Name", typeof(string));
this.myData.Columns.Add("LastModified", typeof(DateTime));
this.myData.Rows.Add(1, "first", DateTime.Now.AddMinutes(-2));
this.myData.Rows.Add(2, "second", DateTime.Now.AddMinutes(-1));
this.myData.Rows.Add(3, "third", DateTime.Now);
this.myData.DefaultView.Sort = "LastModified DESC";
this.comboBox1.DataSource = this.myData.DefaultView;
this.comboBox1.ValueMember = "ID";
this.comboBox1.DisplayMember = "Name";
}
private void saveStuffButton_Click(object sender, EventArgs e)
{
DataRowView preUpdateSelectedItem = (DataRowView)this.comboBox1.SelectedItem;
// OUTPUT: SelectedIndex = 0; SelectedItem.Name = third
Debug.WriteLine(string.Format("SelectedIndex = {0:N0}; SelectedItem.Name = {1}", this.comboBox1.SelectedIndex, preUpdateSelectedItem["Name"]));
this.myData.Rows[0]["LastModified"] = DateTime.Now;
DataRowView postUpdateSelectedItem = (DataRowView)this.comboBox1.SelectedItem;
// OUTPUT: SelectedIndex = 2; SelectedItem.Name = second
Debug.WriteLine(string.Format("SelectedIndex = {0:N0}; SelectedItem.Name = {1}", this.comboBox1.SelectedIndex, postUpdateSelectedItem["Name"]));
// FAIL!
Debug.Assert(object.ReferenceEquals(preUpdateSelectedItem, postUpdateSelectedItem));
}
}
To clarify:
I understand how I would fix the simple application above--I only included that to demonstrate the problem. My concern is how to fix it when the updates to the underlying data rows could be happening anywhere (on another form, perhaps.)
I would really like to still receive updates, inserts, deletes, etc. to my data source. I have tried just binding to an array of DataRows severed from the DataTable, but this causes additional headaches.
Just add a BindingContext to the ComboBox :
this.comboBox1.DataSource = this.myData.DefaultView;
this.comboBox1.BindingContext = new BindingContext();
this.comboBox1.ValueMember = "ID";
this.comboBox1.DisplayMember = "Name";
By the way, try not keeping auto-generated names for your widgets (comboBox1, ...), it is dirty. :-P
The only promising solution I see at this time is to bind the combo box to a detached data source and then update it every time the "real" DataView changes. Here is what I have so far. Seems to be working, but (1) it's a total hack, and (2) it will not scale well at all.
In form declaration:
private DataView shadowView;
In form initialization:
this.comboBox1.DisplayMember = "Value";
this.comboBox1.ValueMember = "Key";
this.shadowView = new DataView(GlobalData.TheGlobalTable, null, "LastModified DESC", DataViewRowState.CurrentRows);
this.shadowView.ListChanged += new ListChangedEventHandler(shadowView_ListChanged);
this.ResetComboBoxDataSource(null);
And then the hack:
private void shadowView_ListChanged(object sender, ListChangedEventArgs e)
{
this.ResetComboBoxDataSource((int)this.comboBox1.SelectedValue);
}
private void ResetComboBoxDataSource(int? selectedId)
{
int selectedIndex = 0;
var detached = new KeyValuePair<int, string>[this.shadowView.Count];
for (int i = 0; i < this.shadowView.Count; i++)
{
int id = (int)this.shadowView[i]["ID"];
detached[i] = new KeyValuePair<int, string>(id, (string)this.shadowView[i]["Name"]);
if (id == selectedId)
{
selectedIndex = i;
}
}
this.comboBox1.DataSource = detached;
this.comboBox1.SelectedIndex = selectedIndex;
}
Must detach event handler in Dispose:
this.shadowView.ListChanged -= new ListChangedEventHandler(shadowView_ListChanged);
Your example sorts the data on the column it updates. When the update occurs, the order of the rows changes. The combobox is using the index to keep track of it's selected items, so when the items are sorted, the index is pointing to a different row. You'll need to capture the value of comboxBox1.SelectedItem before updating the row, and set it back once the update is complete:
DataRowView selected = (DataRowView)this.comboBox1.SelectedItem;
this.myData.Rows[0]["LastModified"] = DateTime.Now;
this.comboBox1.SelectedItem = selected;
From an architecture perspective, the SelectedItem must be cleared when rebinding the DataSource because the DataBinder don't know if your SelectedItem will persist or not.
From a functional perspective, the DataBinder may not be able to ensure that your SelectedItem from you old DataSource is the same in your new DataSource (it can be a different DataSource with the same SelectedItem ID).
Its more an application feature or a custom control feature than a generic databinding process.
IMHO, you have theses choices if you want to keep the SelectedItem on rebind :
Create a reusable custom control / custom DataBinder with a persistance option which try to set the SelectedItem with all your data validation (using a DataSource / item identification to ensure the item validity)
Persist it specifically on your Form using the Form/Application context (like ViewState for ASP.NET).
Some controls on the .NET market are helping you by rebinding (including selections) the control from their own persisted DataSource if the DataSource is not changed and DataBind not recalled. That's the best pratice.
I've been using WinForms databinding to display data from a database mapped with Fluent NHibernate, and that's been working great.
For example, I can just set a DataGridView's DataSource property from an entity's IList property, and voila - there's all the data!
But now I need to start adding and saving new data rows, and that's not going so well. I thought I'd be able to just enable the grid's AllowUserToAddRows property, and new rows would get added to the underlying IList in the entity, but that didn't work.
Then, after a little searching, I tried setting the DataSource property to a BindingList that was populated from the IList, but that's not being updated with new rows either.
During the course of my searches, I also came upon a few people reporting difficulty with WinForms and DataBinding in general, which makes me wonder if I should pursue that approach any further.
Is the DataBinding approach worth continuing? If so, can anyone suggest where I'm going wrong?
Or is it better to just handle all the DataGridView events associated with adding a new row, and writing my own code to add new objects to the IList property in my entity?
Other suggestions? (though I don't think switching to WPF is going to be an option, no matter how much better the databinding may be)
Can you load (or copy) your nHibernate entities into a generic List? If so, I have had good success in with two-way binding using a DataGridView bound to a generic List.
The key points are:
The generic list contains list objects where each is an instance of your custom class.
Your custom class must implement public properties for each of the fields to bind. Public fields didn't work for me.
Use a BindingSource to wrap the actual generic list.
The BindingSOurce allows you to set the AllowNew property to true. Binding directly to the List almost works, but the DataGridVieww does not display the "New row" line, even if AllowUsersToAddRows = true.
For example, add this code to a Form with a dataGridView1:
private List<MyObject> m_data = new List<MyObject>();
private BindingSource m_bs =new BindingSource();
private void Form1_Load(object sender, EventArgs e)
{
m_data.Add(new MyObject(0,"One",DateTime.Now));
m_data.Add(new MyObject(1, "Two", DateTime.Now));
m_data.Add(new MyObject(2, "Three", DateTime.Now));
m_bs.DataSource = m_data;
m_bs.AllowNew = true;
dataGridView1.DataSource = m_bs;
dataGridView1.AutoGenerateColumns = true;
dataGridView1.AllowUserToAddRows = true;
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
for (int i = 0; i < m_data.Count ; i++)
{
Console.WriteLine(string.Format("{0} {1} {2}", m_data[i].ID, m_data[i].Name, m_data[i].DOB));
}
}
}
public class MyObject
{
// Default ctor, required for adding new rows in DataGridView
public MyObject()
{
}
public MyObject(int id, string name, DateTime dob)
{
ID = id;
Name = name;
DOB = dob;
}
private int m_id;
public int ID
{
get
{
return m_id;
}
set
{
m_id = value;
}
}
private string m_name;
public string Name
{
get
{
return m_name;
}
set
{
m_name = value;
}
}
private DateTime m_dob;
public DateTime DOB
{
get
{
return m_dob;
}
set
{
m_dob = value;
}
}
}
When the form closes, the contents of the bound List are printed to the Output window.
I'm developing a Windows Forms application in VS2008. I want to display a unknown, but small number of DataGridViews on a form, using code like this:
foreach (QueryFilter f in Query.Filter)
{
DataGridView grid = CreateGridView(String.Format("GridView{0}", filters.Count));
grid.Location = new System.Drawing.Point(3, 9 + (filters.Count * grid.Height + 9));
BindingList<QueryFilterNode> nodes = new BindingList<QueryFilterNode>();
foreach (QueryFilterNode node in f)
nodes.Add(node);
grid.DataSource = nodes;
panel1.Controls.Add(grid);
filters.Add(nodes);
}
The grid(s) are added to the panel, but the data inside is not displayed. My guess is setting the DataSource property doesn't actualy bind the grid, because (for example) the dataGridView_ColumnAdded event is not fired.
QueryFilter and QueryFilterNode are just POCO's and contain data of course.
For completeness sake the construction of the DataGridView:
private DataGridView CreateGridView(string name)
{
DataGridView grid = new DataGridView();
grid.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
grid.Name = name;
grid.Size = new System.Drawing.Size(484, 120);
grid.ColumnAdded += new System.Windows.Forms.DataGridViewColumnEventHandler(this.dataGridView_ColumnAdded);
return grid;
}
Hmm, it seems it was my own mistake.
QueryFilterNode, used as datasource ( BindingList<QueryFilterNode> ) wasn't a POCO but a datacontract. Snippet:
[DataContract(Name = "QueryFilterNode")]
public class QueryFilterNode
{
[DataMember(IsRequired = true)]
public string FieldCode;
For some reason these cannot be databound. I used a simple class like this in my BindingList and it just worked.
class QueryFilterNodeSimple
{
public string FieldCode
{ get; set; }