|
I thought that you had found the solution, but no. I still get the same problem.
|
|
|
|
|
Doubtful. I use this all the time in a module I created for the application I architected at work. And calling ListView.Items.Clear clears only the items - not the columns as well like ListView.Clear would - which happens on many events in my application and all four views retain their behavior when doing so.
What else are you doing in your ListView? Something else is garbling the list items.
Microsoft MVP, Visual C#
My Articles
|
|
|
|
|
I drop files onto the listView control, and the fullpath to each file is stored into a member ArrayList, the listView shows the file names and their associated icon which is extracted at runtime and placed into an imageList. The index's for the listView, ArrayList and imageList are all kept in sync.
Here's my code, first the InitializeComponent part for the listView:
this.listView1.AllowDrop = true;<br />
this.listView1.CheckBoxes = true;<br />
this.listView1.LabelWrap = false;<br />
this.listView1.LargeImageList = this.imageList1;<br />
this.listView1.Location = new System.Drawing.Point(24, 24);<br />
this.listView1.Name = "listView1";<br />
this.listView1.Size = new System.Drawing.Size(224, 224);<br />
this.listView1.SmallImageList = this.imageList1;<br />
this.listView1.TabIndex = 2;<br />
this.listView1.View = System.Windows.Forms.View.SmallIcon;<br />
this.listView1.DragDrop += new System.Windows.Forms.DragEventHandler(this.listView1_DragDrop);<br />
this.listView1.DragEnter += new System.Windows.Forms.DragEventHandler(this.listView1_DragEnter);
then the two events for Drag 'n' Drop:
private void listView1_DragEnter(object sender, System.Windows.Forms.DragEventArgs e)<br />
{<br />
if(e.Data.GetDataPresent(DataFormats.FileDrop))<br />
e.Effect = DragDropEffects.All;<br />
else<br />
e.Effect = DragDropEffects.None;<br />
}<br />
<br />
private void listView1_DragDrop(object sender, System.Windows.Forms.DragEventArgs e)<br />
{<br />
string[] s = (string[]) e.Data.GetData(DataFormats.FileDrop, false);<br />
for(int i = 0; i < s.Length; i++)<br />
{<br />
<br />
if (!m_szFullFilePaths.Contains (s[i]))<br />
{<br />
<br />
int j = listView1.Items.Count;<br />
m_szFullFilePaths.Capacity = j+1;<br />
m_szFullFilePaths.Add (s[i]);<br />
Regex reg = new Regex (@"\\");<br />
string[] p = reg.Split (s[i]);<br />
listView1.Items.Add(p[p.Length - 1]);<br />
<br />
Icon ico = ExtractIcon.GetIcon (s[i],true, false);<br />
imageList1.Images.Add (ico);<br />
listView1.Items[j].ImageIndex = j;<br />
}<br />
}<br />
}
And finally the button click event for the "Clear" button, so that a fresh selection of files can be made:
private void btnClearLV_Click(object sender, System.EventArgs e)<br />
{<br />
listView1.Items.Clear ();<br />
m_szFullFilePaths.Clear ();<br />
m_szFullFilePaths.Capacity = 0;<br />
imageList1.Images.Clear ();<br />
}
Heres hoping someone can spot the problem, cause I can't.
|
|
|
|
|
One important module of our application that I wrote uses this concept - only in a much better way. Instead of storing the paths in a separate ArrayList, just use the ListViewItem.Tag property. It's there for any use you need. Second, design your icon/filetype lookup so that it caches the information. Why use SHGetFileInfo (well, that's what I use anyway) for files you have already discovered? In fact, the Windows shell does this very thing with a system image list that caches all the icon for file types. If you want, I could send you my implementation. It works on the same principals as what Windows Explorer does and is incredibly fast.
Also, quit messing with the ArrayList.Capacity. This is only used to determine when the capacity should be increased. The default behavior is to double the capacity (best deterministic algorithm) when the count is the same as ahte capacity.
The reason you're probably seeing this "sparsly" placed icons is because you have LabelWrap set to false. The ListView class (and the List View common control it encapsulates) uses fixed-width columns to display items. If an item's text go beyond that, the item's text is spanned however many columns is required to show the full text. This virtual column is not pushed to make room. You'll see this behavior in Windows Explorer as well, for like I mentioned, the ListView class encapsulates the List View common control that Windows Explorer uses.
Microsoft MVP, Visual C#
My Articles
|
|
|
|
|
Thanks for the very helpful advice, I will put it into action latter. I am sure this will resolve the issue.
Thanks
|
|
|
|
|
I am populating a listView with items, and associating each item with an image in an imageList. The listView.View property is set as:
listView.View = View.SmallIcon;
When I add the initial set of items all is fine and the items are listed down the control, but when I use:
listView.Clear();
and re-populate the listView with the same method as before, the items are not listed down the control but are all over the place! Is there a bug or have I not set a property somewhere?
H E L P please
|
|
|
|
|
Hello,
I need to pass an array of strings to a COM object implemented in VB. The Interop interface wants a ref System.Array. How can I convert my String[] to this format in the fastest way possible?
Rickard
|
|
|
|
|
Its already an array:
string[] strs = "a d g v g r d".Split(' ');
Array a = strs;
Mazy
"Improvisation is the touchstone of wit." - Molière
|
|
|
|
|
Take a look at this post. I think it solves your problem.
|
|
|
|
|
I want to open a DAO Recordset
Database tempDB;
Recordset rstbl;
rstbl = tempDB.OpenRecordset("SELECT Name FROM myTblNames", DAO.RecordsetTypeEnum.dbOpenTable, DAO.RecordsetOptionEnum.dbReadOnly , DAO.LockTypeEnum.dbPessimistic );
Error is Invalid argument
|
|
|
|
|
Why are you using DAO? First of all, it was superceeded long ago by ADO. And since this is the C# forum, I can only assume you're using C#. So why aren't you using ADO.NET? It's a hell of a lot easier in .NET applications and has many benefits over plain ADO (like easy parameterized queries, data adapters, and more).
You can find more information about ADO.NET in the .NET Framework SDK: Accessing Data using ADO.NET[^]. There's also several technical articles in MSDN with examples: ADO.NET[^].
Microsoft MVP, Visual C#
My Articles
|
|
|
|
|
If taken a deep look into this hooking article: http://www.codeproject.com/csharp/NetWin32Hooks.asp?target=hook[^]. I had a problem with creating a global hook. The problem with creating a global hook, as some of you might know, is that the hook proc must reside in a seperate library so that it can be loading into all the running processes on the system. The author of the article above has testing just that with a .NET library and claims that it just doesn't work. I came up with a solution that I'm very close to finishing.
Basically I created a C++ library that implements all the hooking and exposes the functions so I can call them. For the .NET application to be able to get the events I resend them to the HWND that is passes when the hook is first installed. I can get the hook to work without a hitch if I call it from another C++ test application. However when I use P/Invoke to call the install function the hook isn't installed globally like expected but only hooks messages in the current thread. (In the C++ test application the hook works globally without a hitch) What am I doing wrong in this case? What is the right way to call the install function? If I can't get this to work I'll have to fall back to creating a C++ exe that will install the hook and initialize the HWND to resend events to.
|
|
|
|
|
Sounds like you're either P/Invoking the method wrong, or not passing the right parameter. Some code fragments (such as the P/Invoked method and the calling method) would help. Otherwise, you're not providing any information with which we can help you. Simply saying "it doesn't work" helps none.
Besides, you'd be better off asking this in the forum for that article, though asking here isn't exactly wrong (just that your question is specific to that article).
Microsoft MVP, Visual C#
My Articles
|
|
|
|
|
I know what are interfaces and what is the logic behind them, but I've never used them practically in any project.
Now I actually want to start incorporating them in my programms practically anc actually in a reasonable way.
I just want to know why should I use them instead of simply using classes? How are they useful when releasing new versions of our products?
Can you please provide me any link, where I can study and learn more about them? notice: practically
Regards!
|
|
|
|
|
I give you some point, you can't inherit from two class in C# but you can inherit from one class and as many as interface you waqnt. Is that enough reason forusing them in OOP world?
Mazy
"Improvisation is the touchstone of wit." - Molière
|
|
|
|
|
So, why interfaces are widely used in VC++, while it is possible to do multiple inheriting there?
|
|
|
|
|
They're great for writing plugins
"if you vote me down, I shall become more powerful than you can possibly imagine" - Michael P. Butler.
Support Bone
It's a weird Life
|
|
|
|
|
|
- Interfaces lets you make multiple inherance.
The best examples are IList,ICollection,IEnumerate from the System.Collections namespace.
- Interfaces makes you focus on design before starting to actually do any coding. Ok, an example.
Consider you need to develop a product that manages customers, products and orders (classic example). Note that when starting to design the product, you do not know "implementation" details like how the data will be stored, etc...
The problem is sufficiently simple we don't have to go through UML and stuff but we can use interfaces to defines the relationships between the objects
public interface ICustomer
{
string Name {get;}
}
public interface IProduct
{
string Name {get;}
}
public interface IOrder
{
ICustomer Customer {get;}
IProduct Product {get;}
int Quantity {get;}
}
Here you can see the relationships between ICustomer, IProduct and IOrder. It is important to note that you have not written any "line of code" yet. You have just defined the objects. After that, you can implement the interface for database data, XMl file etc...
:=)
Jonathan de Halleux.
www.dotnetwiki.org
|
|
|
|
|
there's a couple reasons I use an interface. one of the biggest is so that I can write a function that can handle a generic reference of a class
here's an example I used it for
I created an ILookupTable interface that had methods like
Add(), Edit(), Delete(), SortUp(), SortDown() etc.
and then created several classes that implmented this interface
StateLookupTable,
TelephoneTypeLookupTable,
AddressTypeLookupTable
From there I could create one GUI that handled maintaining my lookup tables. When I needed to pass a class as a parameter, I would have a call like: public void MyCall(ILookupTable table)
and I knew I could call all of the properties and methods in that interface without actually having to know which particular class I was working with.
|
|
|
|
|
I have a two formed application in C#. I need to know how to get an integer from the initial form, to the second one.
|
|
|
|
|
What is the desired behavior of the two forms, i.e., what order will they be displayed, will the both be open at the same time, should one disappear...
Anyway, you might try passing the value from the first form to the constructor of the new form.
|
|
|
|
|
|
Something like this:
namespace FormConstructorParam
{
public class OverloadedConstructor : System.Windows.Forms.Form
{
private System.ComponentModel.Container components = null;
private int _value;
public OverloadedConstructor()
{
InitializeComponent();
}
public OverloadedConstructor(int someValue)
{
InitializeComponent();
_value = someValue;
}
}
}
then, when you create the instance of the form, you do this:
OverloadedConstructor oneForm = new OverloadedConstructor(1);
or this:
OverloadedConstructor anotherForm = new OverloadedConstructor();
|
|
|
|
|
The value could also be stored in a field or a property of either one or both of the forms...
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
