Question

我正在使用WPF制作一个小应用程序，将两个测量值（以英寸为单位）转换为最终的平方英尺答案。然后在我点击＆＃34;计算＆＃34;按钮，它应该将信息添加到ListView。到目前为止，我能够计算出最终的平方英尺，然后在点击“计算”之后将一行信息添加到列表中。按钮无法再添加到ListView。如何将多行不同信息添加到ListView？

C＃：

public partial class MainWindow : Window
{
    List<Dimension> dimensionList = new List<Dimension>();

    public MainWindow()
    {
        InitializeComponent();

    }

    private void calculate_bttn_Click(object sender, RoutedEventArgs e)
    {
        Calculate();           
    }

    private void Calculate()
    {
        //----get height from textbox-------------------print height to console----//
        int height = Int32.Parse(height_TB.Text); Console.WriteLine("Height: " + height);

        //----get width from textbox--------------------print width to console----// 
        int width = Int32.Parse(width_TB.Text); Console.WriteLine("Widht: " + width);

        //----converting square inches into square feet----//
        int toSquareInches = height * width;
        int toSquareFeet = toSquareInches / 144;

        //----create new dimension----//
        Dimension dim = new Dimension();

        //----set dimension properties----////
        dim.height = height;
        dim.width = width;
        dim.sqrInches = toSquareInches;
        dim.sqrFeet = toSquareFeet;

        //----add new dimension to dimensionList----//
        dimensionList.Add(dim);

        //----set binding source for listview----//
        listView.ItemsSource = dimensionList;

        //----display final square footage----//
        total_label.Content = "Total: " + toSquareFeet.ToString() + " square feet";
    }
}


class Dimension
{
    public int height { get; set; }
    public int width { get; set; }   
    public int sqrInches { get; set; }
    public int sqrFeet { get; set; }

    public override string ToString()
    {
        return "height:" + height.ToString() + " width:" + width.ToString() + " Sqr inches:" + sqrInches.ToString() + " Sqr Feet:" + sqrFeet.ToString(); ;
    }
}

XAML：

<Window x:Class="Conversion.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:local="clr-namespace:Conversion"
    mc:Ignorable="d"
    Title="Converter" Height="337.333" Width="397.667">
    <Grid Margin="0,0,2,0">
        <TextBox x:Name="height_TB" HorizontalAlignment="Left" Height="23" Margin="10,16,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120"/>
        <TextBox x:Name="width_TB" HorizontalAlignment="Left" Height="23" Margin="10,44,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120"/>
        <Label x:Name="total_label" Content="Total:" HorizontalAlignment="Left" Margin="10,97,0,0" VerticalAlignment="Top"/>
        <Button x:Name="calcuate_bttn" Content="CALCULATE" HorizontalAlignment="Left" Margin="10,72,0,0" VerticalAlignment="Top" Width="120" Click="calculate_bttn_Click"/>
        <Label x:Name="height_label" Content="height" HorizontalAlignment="Left" Margin="135,12,0,0" VerticalAlignment="Top"/>
        <Label x:Name="width_label" Content="width" HorizontalAlignment="Left" Margin="135,40,0,0" VerticalAlignment="Top" RenderTransformOrigin="-0.111,-2.413"/>
        <ListView x:Name="listView" HorizontalAlignment="Left" Height="168" Margin="10,128,0,0" VerticalAlignment="Top" Width="368">
            <ListView.View>
                <GridView>
                    <GridViewColumn/>
                </GridView>
            </ListView.View>
        </ListView>

    </Grid>
</Window>

Answer 1

您的原始代码已添加多个项目，但未通知用户界面更改。显示的是一项，因为当您设置ItemsSource时，它会导致属性更改为触发（从null到dimensionList）。在您的后续点击中，您设置了相同的集合（dimensionList），该集合不会通知该属性已更改，因为它是同一个对象。

您可以使用ObservableCollection，只要在集合中添加或删除新的Dimension，就可以通知用户界面。

public partial class MainWindow : Window
{
    ObservableCollection<Dimension> dimensionList = new ObservableCollection<Dimension>();

    public MainWindow()
    {
        InitializeComponent();
        //----set binding source for listview----//
        listView.ItemsSource = dimensionList;
    }

    private void calculate_bttn_Click(object sender, RoutedEventArgs e)
    {
        Calculate();           
    }

    private void Calculate()
    {
        //----get height from textbox-------------------print height to console----//
        int height = Int32.Parse(height_TB.Text); Console.WriteLine("Height: " + height);

        //----get width from textbox--------------------print width to console----// 
        int width = Int32.Parse(width_TB.Text); Console.WriteLine("Widht: " + width);

        //----converting square inches into square feet----//
        int toSquareInches = height * width;
        int toSquareFeet = toSquareInches / 144;

        //----create new dimension----//
        Dimension dim = new Dimension();

        //----set dimension properties----////
        dim.height = height;
        dim.width = width;
        dim.sqrInches = toSquareInches;
        dim.sqrFeet = toSquareFeet;

        //----add new dimension to dimensionList----//
        dimensionList.Add(dim);        

        //----display final square footage----//
        total_label.Content = "Total: " + toSquareFeet.ToString() + " square feet";
    }
}

新条目后更新列表视图

1 个答案: