如何在 golang 的 fyne 中循环 fyne.CanvasObject

Question

问题是。我有 NewVScroll 在 NewVScroll 我有 NewVBoxLayout 在 NewVBoxLayout 我有 NewButton 。 问题是当我按下 NewButton 它应该循环 NewVScroll 然后循环 NewVBoxLayout 找到 NewButton 。但我不知道如何在 fyne 中做到这一点，因为我无法循环 var v1 fyne.CanvasObject

错误是：cannot range over v1 (variable of type fyne.CanvasObject)

这是代码

package main

import (
    "fmt"

    "fyne.io/fyne/v2"
    "fyne.io/fyne/v2/app"
    "fyne.io/fyne/v2/container"
    "fyne.io/fyne/v2/layout"
    "fyne.io/fyne/v2/widget"
)

var cEntries *fyne.Container

func FindObject(object fyne.CanvasObject, objects []fyne.CanvasObject) (int, bool) {
    for k1, v1 := range objects {
        for _, v2 := range v1 {// the problem is here. i can't loop over fyne.CanvasObject
            if v2 == object {
                return k1, true
            }
        }
    }
    return 0, false
}

func w1() *fyne.Container {
    wb := widget.NewButton("", nil)

    wb.OnTapped = func() {
        index, isin := FindObject(wb, cEntries.Objects)
        fmt.Println(index, isin)
    }

    return container.New(layout.NewVBoxLayout(), wb)
}

func main() {
    a := app.New()
    w := a.NewWindow("")

    wbAdd := widget.NewButton("+", nil)
    cEntries = container.New(layout.NewVBoxLayout(), wbAdd, w1())

    wbAdd.OnTapped = func() {
        cEntries.Add(w1())
    }

    wsEntries := container.NewVScroll(cEntries)

    w.SetContent(wsEntries)
    w.ShowAndRun()
}

Answer 1

该对象是一个容器，因此通常您可以迭代 v1.(*fyne.Container).Objects。

但是看起来您可以避免在代码中循环，因为按钮总是引用添加按钮时设置的索引 - 因此您可以将当前的 index（长度）传递给 w1 然后增加它。

Answer 2

你不需要循环 NewVBoxLayout 因为它是 fyne.CanvasObject 然后如果你想要知道包含此小部件 NewButton 的布局索引，您只需在中搜索 NewVBoxLayout 即可NewVScroll 这是代码

package main

import (
    "fmt"

    "fyne.io/fyne/v2"
    "fyne.io/fyne/v2/app"
    "fyne.io/fyne/v2/container"
    "fyne.io/fyne/v2/layout"
    "fyne.io/fyne/v2/widget"
)

var cEntries *fyne.Container

func FindObject(object fyne.CanvasObject, objects []fyne.CanvasObject) (int, bool) {
    for k1, v1 := range objects {
        if v1 == object {
            return k1, true
        }
    }
    return 0, false
}

func w1() *fyne.Container {
    wb := widget.NewButton("", nil)
    c := container.New(layout.NewVBoxLayout(), wb)
    wb.OnTapped = func() {
        index, isin := FindObject(c, cEntries.Objects)
        fmt.Println(index, isin)
    }

    return c
}

func main() {
    a := app.New()
    w := a.NewWindow("")

    wbAdd := widget.NewButton("+", nil)
    cEntries = container.New(layout.NewVBoxLayout(), wbAdd, w1())

    wbAdd.OnTapped = func() {
        cEntries.Add(w1())
    }

    wsEntries := container.NewVScroll(cEntries)

    w.SetContent(wsEntries)
    w.ShowAndRun()
}

在这段代码中看到您创建了处理按钮的容器，然后搜索包含此按钮的容器

如何在 golang 的 fyne 中循环 fyne.CanvasObject

how to loop over fyne.CanvasObject in fyne in golang

go

fyne