如何从列表框中检索selecteditems的值？

This is my first UWP app and I'm sure I just missing something very simple.

这是我的第一个UWP应用程序,我确信我只是遗漏了一些非常简单的东西。

I am trying to build an openfilepicker allowing users to select which file types are to be included (.JPEG, .BMP etc) via a listbox. My problem is the value returned from my listbox is invalid. The value returned is "my solution name.page name.Classname" not the value that the user has selected in the list box (for example .JPEG").

我正在尝试构建一个openfilepicker,允许用户通过列表框选择要包含的文件类型(.JPEG,.BMP等)。我的问题是我的列表框返回的值无效。返回的值是“my solution name.page name.Classname”,而不是用户在列表框中选择的值(例如.JPEG“)。

XAML:

        <ListBox x:Name="lstPhotoType" Height="197" SelectionMode="Multiple" FontSize="12" VerticalAlignment="Top" Background="{x:Null}" SelectionChanged="lstPhotoType_SelectionChanged" >
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <Grid VerticalAlignment="Top">
                        <TextBlock x:Name="pictureType" Text="{Binding pType, Mode=TwoWay}" HorizontalAlignment="Left" TextWrapping="Wrap" VerticalAlignment="Top" FontWeight="Bold" FontSize="12"/>
                    </Grid>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>

My c# code:

我的c#代码:

       //Start creating the fileopenpicker.
        FileOpenPicker fileOpenPicker = new FileOpenPicker();
        fileOpenPicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;

        //Count the number of selected photos files.
        int count = lstPhotoType.SelectedItems.Count();

        //If 1 of  more photo type/s has been selected - build openpicker filetypefilter.
        if (count > 0)
        {
            foreach (object listBoxItem in lstPhotoType.SelectedItems)
            {
               // string value = Convert.ToString(listBoxItem);
                fileOpenPicker.FileTypeFilter.Add(listBoxItem.ToString());
            }
        }

Any suggestions would be greatly appreciated.

任何建议将不胜感激。

Edit 1

My class code for PictureTypes

我的PictureTypes的类代码

    public class PictureTypes
    {
        public string pType { get; set; }
    }

    string[] arrayoftypes = new string[5] { "*All", ".BMP", ".JPEG", ".JPG", ".PNG"};

    public void makePictureTypeList()
    {
        for (int i = 0; i < 5; i++)
        {
            //Create a new instace of the PictureTypes class
            PictureTypes obj = new PictureTypes();

            //build array of data
            obj.pType = arrayoftypes[i];

            //Add the the picture types into the listbox
            lstPhotoType.Items.Add(obj);
        }
    }

2 个解决方案

#1

You should be able to cast the items in the SelectedItems collection to your type where the "pType" property is defined and access this property directly:

您应该能够将SelectedItems集合中的项目转换为定义了“pType”属性的类型,并直接访问此属性:

if (count > 0)
{
    foreach (PictureTypes listBoxItem in lstPhotoType.SelectedItems.OfType<PictureTypes>())
    {
        fileOpenPicker.FileTypeFilter.Add(listBoxItem.pType);
    }
}

Or you could use the dynamic type:

或者您可以使用动态类型:

if (count > 0)
{
    foreach (dynamic listBoxItem in lstPhotoType.SelectedItems)
    {
        fileOpenPicker.FileTypeFilter.Add(listBoxItem.pType);
    }
}

Thanks mm8, but debugging still shows pType as "my solution name.page name.Classname

谢谢mm8,但调试仍然显示pType为“我的解决方案名称.page name.Classname

What does "debugging" mean in this case? This will get you the currently selected string values:

在这种情况下,“调试”是什么意思?这将获得当前选择的字符串值:

private void lstPhotoType_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        int count = lstPhotoType.SelectedItems.Count();
        if (count > 0)
        {
            foreach (PictureTypes listBoxItem in lstPhotoType.SelectedItems.OfType<PictureTypes>())
            {
                string value = listBoxItem.pType; //<- value = ".BMP" or ".JPG", etc.
            }
        }
    }

#2

Try this: to get selected item value.

试试这个:获取所选项目值。

string text = listBoxItem.GetItemText(listBoxItem.SelectedItem);

EDIT

Try below approach this should work:

尝试以下方法,这应该工作:

int index;
string  item;
foreach (int i in lstPhotoType.SelectedIndices)
{
    index = lstPhotoType.SelectedIndex;
    item = lstPhotoType.Items[i].ToString ();
    MessageBox.Show(item);
}

#1