Golang跨平台GUI框架Fyne的使用教程详解

$ mkdir hellofyne
$ cd helloyfyne
$ go mod init hellofyne
$ go get fyne.io/fyne/v2@latest
$ go install fyne.io/fyne/v2/cmd/fyne@latest

$ go run fyne.io/fyne/v2/cmd/fyne_demo@latest

package main

import (
    "fyne.io/fyne/v2/app"
    "fyne.io/fyne/v2/container"
    "fyne.io/fyne/v2/widget"
)

func main() {
    a := app.New()
    w := a.NewWindow("Hello Fyne")
    w.SetContent(widget.NewLabel("Welcome to Fyne!"))
    w.ShowAndRun()
}

w.Resize(fyne.NewSize(100, 100))

btn := widget.NewButton("Create a widnow", func() {
    w2 := a.NewWindow("Window 02")
    w2.Resize(fyne.NewSize(200, 200))
    w2.Show()
})

w.SetContent(btn)

w.SetContent(container.NewHBox(widget.NewButton("Left", func() {
    fmt.Println("Left button clicked")
}), widget.NewButton("Right", func() {
    fmt.Println("Right button clicked")
})))

w.SetContent(container.NewVBox(widget.NewButton("Top", func() {
    fmt.Println("Top button clicked")
}), widget.NewButton("Bottom", func() {
    fmt.Println("Bottom button clicked")
})))

// 标签 Label
label := widget.NewLabel("Label")
// 按钮 Button
button := widget.NewButton("Button", func() {})
// 输入框 Entry
entry := widget.NewEntry()
entry.SetPlaceHolder("Entry")
// 复选框 Check
check := widget.NewCheck("Check", func(bool) {})
// 单选框 Check
radio := widget.NewRadioGroup([]string{"Option 1", "Option 2"}, func(string) {})
// 选择框
selectEntry := widget.NewSelectEntry([]string{"Option A", "Option B"}
// 进度条
progressBar := widget.NewProgressBar()
// 滑块
slider := widget.NewSlider(0, 100)
// 组合框
combo := widget.NewSelect([]string{"Option A", "Option B", "Option C"}, func(string) {})
// 表单项
formItem := widget.NewFormItem("FormItem", widget.NewEntry())
form := widget.NewForm(formItem)
// 手风琴
accordion := widget.NewAccordion(widget.NewAccordionItem("Accordion", widget.NewLabel("Content")))
// Tab 选择
tabs := container.NewAppTabs(
    container.NewTabItem("Tab 1", widget.NewLabel("Content 1")),
    container.NewTabItem("Tab 2", widget.NewLabel("Content 2")),
)

// 弹出对话框示例按钮
dialogButton := widget.NewButton("Show Dialog", func() {
    dialog.ShowInformation("Dialog", "Dialog Content", w)
})

// 滚动布局
content := container.NewVScroll(container.NewVBox(
    label, button, entry, check, radio, selectEntry, progressBar, slider,
    combo, form, accordion, tabs, dialogButton,
))
w.SetContent(content)

type Widget interface {
    CanvasObject
    CreateRenderer() WidgetRenderer
}

type WidgetRenderer interface {
    Destroy()
    Layout(Size)
    MinSize() Size
    Objects() []CanvasObject
    Refresh()
}

type CustomLabel struct {
    widget.BaseWidget
    Text string
}

func NewCustomLabel(text string) *CustomLabel {
    label := &CustomLabel{Text: text}
    label.ExtendBaseWidget(label)
    return label
}

type customWidgetRenderer struct {
    text  *canvas.Text // 使用canvas.Text来绘制文本
    label *CustomLabel
}

func (label *CustomLabel) CreateRenderer() fyne.WidgetRenderer {
    text := canvas.NewText(label.Text, theme.ForegroundColor())
    text.Alignment = fyne.TextAlignCenter

    return &customLabelRenderer{
        text:  text,
        label: label,
    }
}

func (r *customLabelRenderer) MinSize() fyne.Size {
    return r.text.MinSize()
}

func (r *customLabelRenderer) Layout(size fyne.Size) {
    r.text.Resize(size)
}

func (r *customLabelRenderer) Refresh() {
    r.text.Text = r.label.Text
    r.text.Color = theme.ForegroundColor() // 确保文本颜色更新
    r.text.Refresh()
}

func (r *customLabelRenderer) BackgroundColor() color.Color {
    return theme.BackgroundColor()
}

func (r *customLabelRenderer) Objects() []fyne.CanvasObject {
    return []fyne.CanvasObject{r.text}
}

func (r *customLabelRenderer) Destroy() {}

a := app.New()
w := a.NewWindow("Custom Label")

w.SetContent(NewCustomLabel("Hello"))
w.ShowAndRun()

// 创建一个字符串绑定
textBind := binding.NewString()

// 创建一个 Entry，将其内容绑定到 textBind
entry := widget.NewEntryWithData(textBind)

// 创建一个 Label，也将其内容绑定到同一个 textBind
label := widget.NewLabelWithData(textBind)

// 使用容器放置 Entry 和 Label，以便它们都显示在窗口中
content := container.NewVBox(entry, label)

func NewCustomLabelWithData(data binding.String) *CustomLabel {
    label := &CustomLabel{}
    label.ExtendBaseWidget(label)
    data.AddListener(binding.NewDataListener(func() {
        text, _ := data.Get()
        label.Text = text
        label.Refresh()
    }))
    return label
}