Category: Listview item collection

All the items on the ListView control form a collection: the Items collection. These members are discussed next. Add method — This method adds a new item to the Items collection.

The syntax of the Add method is as follows:. You can also specify the index of the image to be used, along with the item and a collection of subitems to be appended to the new item, by using the following form of the Add method:. Finally, you can create a ListViewItem object in your code and then add it to the ListView control by using the following form of the Add method:.

The following statements create a new item, set its individual subitems, and then add the newly created ListViewItem object to the control:.

Each item in the ListView control may have one or more subitems. You can think of the item as the key of a record, and the subitems as the other fields of the record. The subitems are displayed only in Details mode, but they are available to your code in any view. To access the subitems of a given item, use its SubItems collection. The following statements add an item and three subitems to the ListView1 control:.

To access the SubItems collection, you need a reference to the item to which the subitems belong. Displaying the subitems on the control requires some overhead. Subitems are displayed only in Details view mode. However, setting the View property to Details is not enough. You must first create the columns of the Details view, as explained earlier.

The ListView control displays only as many subitems as there are columns in the control. The first column, with the header Company, displays the items of the list. The following columns display the subitems. The first subitem Maria Anders in the preceding example will be displayed under the second header, the second subitem in the same example will be displayed under the third header, and so on. At runtime, the user can rearrange the columns by dragging them with the mouse.

ListItem Object and ListItems Collection of ListView Control - Visual Basic 6

The width of individual columns is specified in pixels, and you can set it to a percentage of the total width of the control, especially if the control is docked to the form. The following code sets up a ListView control with four headers, all having the same width:.The following code example demonstrates how to add items to a ListView.

Call the InitializeListView method from the form's constructor or Load event handler. A ListView. There are two other collections defined within the ListView class that enable you to determine what items are selected within a ListView control. The ListView. SelectedListViewItemCollection class provides properties and methods for determining what items are selected in a ListView control, while the ListView. SelectedIndexCollection class enables you to determine what indexes within the ListView.

In addition to selection collection classes, there are also two classes that enable you to determine what items are checked when the CheckBoxes property of the ListView control is set to true within this collection.

There are a number of ways to add items to the collection. The Add method adds a single item to the collection. To add a number of items to the collection, you create an array of items and pass it to the AddRange method. If you want to insert an item at a specific location in the collection, you can use the Insert method.

To remove items, you can use either the Remove method or the RemoveAt method if you know where the item is located in the collection.

listview item collection

The Clear method enables you to remove all items from the collection instead of using the Remove method to remove a single item at a time. In addition to methods and properties for adding and removing items, the ListView. ListViewItemCollection also provides methods to find items in the collection.

The Contains method enables you to determine whether an item is a member of the collection. Once you know that the item is located in the collection, you can use the IndexOf method to determine where the item is located in the collection.

Initializes a new instance of the ListView. ListViewItemCollection class. Adds an existing ListViewItem to the collection.

Adds an array of ListViewItem objects to the collection. Gets the Type of the current instance. Inserts an existing ListViewItem into the collection at the specified index. Creates a new item with the specified image index and inserts it into the collection at the specified index. Creates a new item with the specified text and image and inserts it in the collection at the specified index.I put a breakpoint on that line.

The reason this particular exception gets thrown is that the content of the element gets applied to the ListView's Items collection. But when using an ItemsControl you must use either the Items property or the ItemsSource property, you can't use both at the same time. Hence when the ItemsSource attribute gets processed an exception is thrown.

listview item collection

You can find out which property the content of an element will get applied to by looking for the ContentPropertyAttribute on the class.

In this case it's defined higher in the class hierarchy, on the ItemsControl:. The intention here was that the ListView's View be set to a local:ImageView so the fix is to explicitly indicate the property to be set. Handles MyBase. Loaded ListViewImages. Zack Peterson. Bulk Delete. Bulk Update. Bulk Merge. Accepted Answer The reason this particular exception gets thrown is that the content of the element gets applied to the ListView's Items collection. In this case it's defined higher in the class hierarchy, on the ItemsControl: [ContentPropertyAttribute "Items" ] The intention here was that the ListView's View be set to a local:ImageView so the fix is to explicitly indicate the property to be set.

C# ListView Tutorial: Windows Forms

Popular Answer I had this same error for a while in a slightly different scenario. View more on Stack Overflow. Prime Library. Not affiliated with Stack Overflow.

SaveChanges vs BulkSaveChanges. Try for free now.Hi peeps, im really stuck with how the collection editor is handeling adding items to the items collection in the listview. I have played about with it see the code below and i have got it all working if i type the code out my self but the collection editor is really giving me some trouble, when i add a new item it still calls ita "listviewitem" but i can see the properties of my ListviewitemGOD - i guess this is because if i do a me.

What i dont under stand is even though the collection editior has been told to use my collection which holds my listviewitemsGODs it returns normal listviewitems. So to give a simple recap, the collection editor seems to add the items ok but returns normal items and so the code generator does declare the items correctly in the designer code but tries to initialize them like so ListViewItem ""CustomControls.

Addrange New CustomControls. Here is the rest of my code that i think you will need to see to help. End Get. End Property. End Sub. Return GetType CustomControls.

End Function. End Class. Inherits Windows. Return CType MyBase. End Set. The following is a sample to override this method.

C# Tutorial - ListView Control - FoxLearn

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Remove From My Forums. Asked by:. Windows Forms. Windows Forms General. Sign in to vote. Type MyBase.Overview: In the following sections, we first explore the View property, and then investigate how to add items.

There are many different settings for the View property on the ListView. This property determines how the icons in the control are displayed.

In the top screenshot, the setting is LargeIcon. Next we see the SmallIcon setting. Next, we see the List setting on the View property. You can see that the icons are arranged in a vertical line on the left of the control region. Lists are good for sequential data numbered items. Finally, there is a Tile setting. Similar to the tile setting in Windows Explorer, this setting adds whitespace, which may help the visual appearance of the control.

Be careful not to add too much. The Items property is the most important one on the ListView. It enables you to add the data entries.

listview item collection

However: More useful, you can add elements dynamically through C code, as in the Load event handler on the enclosing form. We can add CheckBox controls to every item. To do this, please set the CheckBoxes property to true. The user will then be able to check or uncheck various items in the ListView through the user interface.

Checked: You can set this to true or false to mutate the check programmatically, or read it to see if the user checked the item. Next: Add images to the ImageList by right-clicking on it and selecting properties. Then open the Images Collection Editor dialog box.As with the TreeView control, the ListView control can be populated either at design time or at runtime.

To add items at design time, click the ellipsis button next to the ListItems property in the Properties window. When the ListViewItem Collection Editor dialog box pops up, you can enter the items, including their subitems, as shown in Figure 4. Click the Add button to add a new item. Each item has subitems, which you can specify as members of the SubItems collection. The first subitem the one with zero index is actually the main item of the control.

Notice that you can set other properties such as the color and font for each item, the check box in front of the item that indicates whether the item is selected, and the image of the item. Use this window to experiment with the appearance of the control and the placement of the items, especially in Details view because subitems are visible only in this view. Note that you can add more subitems than there are columns in the control.

Some of the subitems will remain invisible. Unlike the TreeView control, the ListView control allows you to specify a different appearance for each item and each subitem. Almost all ListView controls are populated at runtime. Not only that, but you should be able to add and remove items during the course of the application. The items of the ListView control are of the ListViewItem type, and they expose members that allow you to control the appearance of the items on the control.

These members are as follows:. Checked property — This property controls the status of an item. You can also select an item from within your code by setting its Checked property to True. Font property — This property sets the font of the current item. By default, subitems inherit the style of the basic item. Text property — This property indicates the caption of the current item or subitem.

To retrieve a specific subitem, use a statement such as the following:. To add a new subitem to the SubItems collection, use the Add method, passing the text of the subitem as an argument:. The argument of the Add method can also be a ListViewItem object. Create a ListViewItem, populate it, and then add it to the Items collection as shown here:.

If you want to add a subitem at a specific location, use the Insert method. The Insert method of the SubItems collection accepts two arguments: the index of the subitem before which the new subitem will be inserted, and a string or ListViewItem to be inserted:. Like the ListViewItem objects, each subitem can have its own font, which is set with the Font property.

The items of the ListView control can be accessed through the Items property, which is a collection. As such, it exposes the standard members of a collection, which are described in the following section. Its item has a SubItems collection that contains all the subitems of the corresponding item.

Figure 4. Items idx1. SubItems idx2. Add "subitem's caption". Add "Its first subitem". Add "Its second subitem". Add LI. Insert idxsubitem.Each item in the ListView is called a ListItem object. If you look at Figure 4. The ListItems Collection can be used to cycle through all the objects in the control for processing, just as with any other collection see Listing 4. You can refer to a specific item by number:.

Alternatively you can loop through the collection of ListItems, referring to each by number, as illustrated in Listing 4. Count Msgbox ListView1. ListItems I. Text Next I. Specifying an Index number is discussed later in this section. A more convenient way to reference an item in the list is by Key. The Key property is a string expression—assigned by you as the developer or by the user if you desire —that can also be used to access an item in the list. The Key property is included as part of the Add method discussed later when an item is inserted into the list.

"Items collection must be empty before using ItemsSource."

As a developer you usually know the value for the Key and can access a node directly. It is easier to refer to the node you want by using a meaningful text string than by using the Index property that is determined by Visual Basic.

You can refer to a specific item by number: Msgbox ListView1. ListItems 1. Text Alternatively you can loop through the collection of ListItems, referring to each by number, as illustrated in Listing 4.

Using the TreeView Control. Using the ToolBar Control.


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