为什么默认情况下我的winform列表视图项不显示？

Question

I have a winforms app and i have listview. Through the visual designer, I add a bunch of items and set the "checked" property to true on all of the items. When i start my app none of the items are selected which seems odd.

Even after I tried adding this code:

         for (int i = 0; i < listView1.Items.Count; i++)
        {
            listView1.Items[i].Selected = true;
        }

when i startup my app (its a vsto app), none of the items are selected. I am choosing LargeIconView (not sure if that makes a difference)

How can i default a listview to have all items checked by default at startup?

Answer 1

The reason your code isn't working is because the ListView control doesn't have focus. Two things you could do are to

1) Set the TabIndex property of the control to be the lowest on the form (likely 0)

2) Select the ListView programmatically

private void Form1_Load(object sender, EventArgs e)
{
   listView1.Select();
   for (int i = 0; i < listView1.Items.Count; i++)
   {
       listView1.Items[i].Selected = true;
   }
}

Answer 2

The checked property is relevant only if the ListView's property of CheckBoxes is set to True. Checked is not the same thing as Selected.

Your code to select all the items works for me. But perhaps, as keyboardP suggests, your issue is related to Focus. Edited : Yes, it only works because I am testing it and this is the only control on my form.

Answer 3

"How can i default a listview to have all items checked by default at startup?"

Change:

        listView1.Items[i].Selected = true;

To:

        listView1.Items[i].Checked = true;

Not sure why the setting isn't "sticking" if you already set them all to checked thru the IDE. Are you modifying the contents of the ListView when the form is loading?