Question

我想在WPF C＃应用程序中添加一项功能，允许用户执行以下操作：

当您按下按钮时，会在画布的角落创建一个文本框，当您完成输入并再次按下该按钮时，下一次单击将在画布上设置此文本框的新位置。

我尝试编写代码但看起来不太稳定，而且我得到了一个错误，如下所示：

int i = 0;

System.Windows.Point currentPoint = new System.Windows.Point();

private void button1_Click(object sender, RoutedEventArgs e, System.Windows.Input.MouseEventArgs e2)
{
    i = i + 1;
    if (i == 1)
    {
        TextBlock TB = new TextBlock();
        TB.Text = "Successfull";
        TB.Background = Brushes.White;
        TB.Name = "TextB";
        myCanvas.Children.Add(TB);

        Canvas.SetLeft(TB, 10);
        Canvas.SetTop(TB, 10);
    }

    if (i == 2)
    {
        Thread.Sleep(500);
        while (e2.LeftButton != MouseButtonState.Pressed)
        {
             Thread.Sleep(50);
        }
        if (e2.LeftButton == MouseButtonState.Pressed)
        {
            currentPoint = e2.GetPosition(this);
            Canvas.SetLeft(TB, currentPoint.X);
            Canvas.SetTop(TB, currentPoint.Y);
        }
        i=0;
    }

}

但是我在“if”语句中声明了我的文本框（TB），所以当我尝试修改它的位置时，它被认为是未知的Canvas.SetLeft(TB, currentPoint.X); 。如果我在外面声明它，即使没有按下按钮，也会创建文本框。有什么想法吗？

此外，如果您有另一种看起来不那么难看的解决方案，请随时分享！

Answer 1

潜力（但老实说，快速和肮脏的），解决方案可能是以下MainWindow.xaml：

<Window x:Class="CanvasTextBox.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto" />
        <RowDefinition Height="*" />
    </Grid.RowDefinitions>
    <Button Grid.Row="0" Click="OnButtonClick" >Click Me</Button>
    <Canvas Grid.Row="1" Background="LightSkyBlue" 
            x:Name="PositioningCanvas"
            PreviewMouseUp="OnPreviewMouseUp">
        <TextBox x:Name="TextBox" Visibility="Collapsed" MinWidth="80" />
    </Canvas>
</Grid>

使用MainWindow.cs：

    public MainWindow()
    {
        InitializeComponent();
    }

    private bool isTextEditing;

    private void OnButtonClick(object sender, RoutedEventArgs e)
    {
        if (!isTextEditing)
        {
            TextBox.Visibility = Visibility.Visible;
            isTextEditing = true;
        }
        else
        {
            isTextEditing = false;
        }
    }

    private void OnPreviewMouseUp(object sender, MouseButtonEventArgs e)
    {
        // As long as your TextBox.Visibility is Collapsed and the user is in 'textEditing' after the
        // first click, don't handle clicks in the Canvas
        if (!isTextEditing && TextBox.Visibility == Visibility.Visible)
        {
            Point clickPoint = e.GetPosition(PositioningCanvas);
            Canvas.SetTop(TextBox, clickPoint.Y);
            Canvas.SetLeft(TextBox, clickPoint.X);
        }
    }

将文本框添加到用户选择的位置的wpf画布（C＃）

1 个答案: