Question

我使用的是适用于Windows Phone的相同类型的代码，但现在在WPF桌面应用程序中使用它。

这会读取一个目录，然后读取目录中的每个xml，然后读取xml并将详细信息广告到_item类。

它似乎正在向_item添加每个单独的项目（比如它从目录中读取3 xml），但是列表中填充了三个具有相同细节的项目 - （从它读取的最后一个xml）。我在这里做错了什么？

enter image description here

C＃

foreach (string fileNameXML in fileEntries)
            {

                    //read 1 xml at a time.
                    XmlDocument doc = new XmlDocument();
                    doc.Load(fileNameXML);
                    XmlNodeList nodes = doc.DocumentElement.SelectNodes("/Job");
                    foreach (XmlNode node in nodes)
                    {
                        _item.Input = node.SelectSingleNode("Input").InnerText;
                        _item.OutputFolder = node.SelectSingleNode("OutputFolder").InnerText;
                        _item.OutputFile = node.SelectSingleNode("OutputFile").InnerText;
                        _item.Format = node.SelectSingleNode("Format").InnerText;
                        _item.Name = node.SelectSingleNode("Name").InnerText;
                        _item.Effects = node.SelectSingleNode("Effect").InnerText;
                        _item.Type = node.SelectSingleNode("Type").InnerText;
                        _item.Output = _item.OutputFolder + _item.OutputFile + "." + _item.Format.ToLower();

                       lstBoxQueue.Items.Add(_item);

                    }
                }

            }

XAML：

 <ListBox Name="lstBoxQueue"  BorderBrush="{x:Null}" Background="#FFA09F9F" ScrollViewer.HorizontalScrollBarVisibility="Disabled" ScrollViewer.VerticalScrollBarVisibility="Visible">
                        <ListBox.ItemTemplate>
                            <DataTemplate>
                        <Grid Height="80" Width="629" HorizontalAlignment="Left" Background="#FFCDCDCD" >
                            <Border BorderBrush="Gray" BorderThickness="1"/>
                            <TextBlock Text="Job name: "  Margin="9,10,432,49" FontWeight="Bold" Foreground="#FF323232" FontSize="12" />
                            <TextBlock Foreground="Black" HorizontalAlignment="Left" MinWidth="50" FontSize="10" TextWrapping="Wrap" Text="{Binding Input}" Margin="76,33,0,0"  VerticalAlignment="Top" MaxWidth="270" MaxHeight="15"/>
                            <TextBlock Foreground="Black" HorizontalAlignment="Left" FontSize="10" TextWrapping="Wrap" Text="{Binding Output}" Margin="77,54,0,0"  MinWidth="100" MaxWidth="270" VerticalAlignment="Top"  />
                            <TextBlock Foreground="Black" HorizontalAlignment="Left" MinWidth="50" FontSize="10" TextWrapping="Wrap" Text="{Binding Name}" Margin="76,12,0,0"  VerticalAlignment="Top" />
                            <TextBlock Foreground="Black" HorizontalAlignment="Left" FontSize="10" TextWrapping="Wrap" Text="{Binding Effects}" Margin="374,31,0,0"  MinWidth="100" MaxWidth="270" VerticalAlignment="Top" Height="40"  />
                            <TextBlock Foreground="Black" HorizontalAlignment="Left" FontSize="10" TextWrapping="Wrap" Text="{Binding Type}" Margin="374,11,0,0"  MinWidth="100" MaxWidth="270" VerticalAlignment="Top" Height="15"  />
                            <Button Content="More Info.." Width="80" Height="25" Margin="538,10,11,45"/>
                            <Button Content="Cancel Job" Width="80" Height="25" Click="ClickCancelJob" Margin="539,43,10,12"/>


                            <TextBlock  Text="Output: " Margin="25,52,414,7" FontWeight="SemiBold" Foreground="#FF323232"/>
                            <TextBlock Text="Effects: " Margin="351,29,102,30" FontWeight="SemiBold" Foreground="#FF323232"/>
                            <TextBlock Text="Input: " Margin="33,30,430,29" FontWeight="SemiBold" Foreground="#FF323232"/>
                            <TextBlock Text="Export Type: " Margin="318,10,100,49" FontWeight="SemiBold" Foreground="#FF323232"/>
                        </Grid>
                          </DataTemplate>
                        </ListBox.ItemTemplate>
                    </ListBox>

项目类：

class XMLItems
    {
        //Accessor class for properties of jobs. Enables all pages to access the job properties.
        private string _input;
        private string _outputFolder;
        private string _outputFile;
        private string _output;
        private string _name;
        private string _effects;
        private string _type;
        private string _format;

        public string Input
        {
            get { return _input; }
            set { _input = value; }
        }

        public string OutputFolder
        {
            get { return _outputFolder; }
            set { _outputFolder = value; }
        }

        public string OutputFile
        {
            get { return _outputFile; }
            set { _outputFile = value; }
        }

        public string Output
        {
            get { return _output; }
            set { _output = value; }
        }

        public string Name
        {
            get { return _name; }
            set { _name = value; }
        }

        public string Effects
        {
            get { return _effects; }
            set { _effects = value; }
        }
        public string Type
        {
            get { return _type; }
            set { _type = value; }
        }

        public string Format
        {
            get { return _format; }
            set { _format = value; }
        }
    }

Answer 1

您的foreach每次都会添加相同的_item引用，并在下次循环运行时对其进行修改。结果很可能是最后一份工作在所有职位上都显示出来。

在内部_item循环中将foreach创建为局部变量，这样每个项目都独立于最后一个：

foreach (string fileNameXML in fileEntries)
{
    //read 1 xml at a time.
    XmlDocument doc = new XmlDocument();
    doc.Load(fileNameXML);
    XmlNodeList nodes = doc.DocumentElement.SelectNodes("/Job");
    foreach (XmlNode node in nodes)
    {
        var item = new MyItem(); // Whatever type _item was.

        item.Input = node.SelectSingleNode("Input").InnerText;
        item.OutputFolder = node.SelectSingleNode("OutputFolder").InnerText;
        item.OutputFile = node.SelectSingleNode("OutputFile").InnerText;
        item.Format = node.SelectSingleNode("Format").InnerText;
        item.Name = node.SelectSingleNode("Name").InnerText;
        item.Effects = node.SelectSingleNode("Effect").InnerText;
        item.Type = node.SelectSingleNode("Type").InnerText;
        item.Output = item.OutputFolder + item.OutputFile + "." + item.Format.ToLower();

       lstBoxQueue.Items.Add(item);
    }
}

列表框未按预期更新

1 个答案: