模态弹出窗口应该像你描述的那样工作。你可能对提供标准模态对话框的对话框包感兴趣。如果模态显示不工作，那么对话框也不工作？
我怀疑这个问题是因为你为模态创建了新的窗口，但是要成为一个模态，它必须和你想要它覆盖的内容在同一个窗口上。

经过很多doo最后我有模态弹出工作，也感谢Andy.xyz.我希望有更多的小代码的例子在fyne文档.我张贴我的工作解决方案在这里任何人评论和/或作出改进.与感谢.
代码有一个主窗口和一个按钮，可以打开一个带有关闭模式按钮的模式。

package main
    import (
        "image/color"
        "fyne.io/fyne/v2/app"
        "fyne.io/fyne/v2/canvas"
        "fyne.io/fyne/v2/container"
        "fyne.io/fyne/v2/widget"
    )
    func main() {
        // Create a new Fyne application
        a := app.New()
    
        // Create a new window with a title
        w := a.NewWindow("Pop up demo by DaHerb")
    
        // Create a label widget with a message
        hello := widget.NewLabel("Demo Fyne show popup vs show modal popup")
    
        // Create a button widget to trigger the pop-up
        showPopUpButton := widget.NewButton("Show Pop-up", nil)
    
        // Define content and canvas objects for the pop-up
        content := canvas.NewText("This is the content of the pop-up", 
        color.Black)
    
        // Declare a variable to hold the pop-up widget
        var popup *widget.PopUp
    
        // Define an action when the "Show Pop-up" button is tapped
        showPopUpButton.OnTapped = func() {
            // Create a container for the pop-up content, including a "Close" 
       button
            popUpContent := container.NewVBox(
                content,
                widget.NewButton("Close", func() {
                    popup.Hide() // Function to hide the pop-up
                }),
            )
    
            // Create a modal pop-up using the content and the main window's 
     canvas
            popup = widget.NewModalPopUp(popUpContent, w.Canvas())
    
            // Show the modal pop-up
            popup.Show()
        }
    
        // Set the main window's content to include the label and the Show-Pop- 
         up button
        w.SetContent(container.NewVBox(
            hello,
            showPopUpButton,
        ))
        // Show the main window and run the application
        w.ShowAndRun()
    }

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