Go GUI项目实战：基于fyne开发简易MarkDown

迈不过友情╰ 2024-03-17 10:59 45阅读 0赞

## Go GUI项目实战：基于fyne开发简易MarkDown ##

> fyne是一个用go编写的GUI框架，它上手简单，语法清晰，界面美观。  
> 教程地址：
> 
>  *  https://pkg.go.dev/fyne.io/fyne/v2\#section-readme
>  *  https://www.topgoer.cn/docs/goday/goday-1crdp17nj4v6p

`项目地址`：https://gitee.com/Zifasdfa/ziyiMarkDown

### 1 基础框架搭建 ###

> 首先需要有go的环境【我的本地环境是1.17】
> 
>  *  go环境搭建过程：https://editor.csdn.net/md/?articleId=130175889

package main
    
    import (
    	"fyne.io/fyne/v2"
    	"fyne.io/fyne/v2/app"
    	"fyne.io/fyne/v2/container"
    	_ "fyne.io/fyne/v2/dialog"
    	_ "fyne.io/fyne/v2/storage"
    	"fyne.io/fyne/v2/widget"
    	"github.com/flopp/go-findfont"
    	_ "io/ioutil"
    	"os"
    	"strings"
    )
    
    /*
    	用fyne实现简易版typora
    */
    
    func init() {
        
    	//设置中文字体:解决中文乱码问题
    	fontPaths := findfont.List()
    	for _, path := range fontPaths {
        
    		if strings.Contains(path, "msyh.ttf") || strings.Contains(path, "simhei.ttf") || strings.Contains(path, "simsun.ttc") || strings.Contains(path, "simkai.ttf") {
        
    			os.Setenv("FYNE_FONT", path)
    			break
    		}
    	}
    }
    
    type config struct {
        
    	EditWidget    *widget.Entry    //编辑框
    	PreviewWidget *widget.RichText //预览框【富文本】
    	CurrentFile   fyne.URI
    	SaveMenuItem  *fyne.MenuItem
    }
    
    var cfg config
    
    func main() {
        
    	a := app.New()
    	win := a.NewWindow("Markdown")
    	edit, preview := cfg.makeUI()
    	cfg.createMenuItems(win)
    	//布局选择左右布局，一边是编辑，一边是预览
    	win.SetContent(container.NewHSplit(edit, preview))
    
    	win.Resize(fyne.Size{
        Width: 800, Height: 500})
    	win.CenterOnScreen()
    	win.ShowAndRun()
    }
    
    //初始化界面
    func (app *config) makeUI() (*widget.Entry, *widget.RichText) {
        
    	edit := widget.NewMultiLineEntry()
    	preview := widget.NewRichTextFromMarkdown("")
    	app.EditWidget = edit
    	app.PreviewWidget = preview
    	edit.OnChanged = preview.ParseMarkdown
    
    	return edit, preview
    }
    
    添加过滤器，只能打开.md结尾文件
    //var filter = storage.NewExtensionFileFilter([]string{".md", ".MD"})
    //
    //创建主菜单
    func (app *config) createMenuItems(win fyne.Window) {
        
    	openMenuItem := fyne.NewMenuItem("open...", func() {
        })
    
    	saveMenuItem := fyne.NewMenuItem("Save...", func() {
        })
    	
    	app.SaveMenuItem = saveMenuItem
    	app.SaveMenuItem.Disabled = true
    	saveAsMenuItem := fyne.NewMenuItem("Save as...", func() {
        })
    
    	fileMenu := fyne.NewMenu("File", openMenuItem, saveMenuItem, saveAsMenuItem)
    
    	menu := fyne.NewMainMenu(fileMenu)
    
    	win.SetMainMenu(menu)
    }

### 2 实现另存为功能 ###

>  *  添加过滤器
>  *  实现另存为

package main
    
    import (
    	"fyne.io/fyne/v2"
    	"fyne.io/fyne/v2/app"
    	"fyne.io/fyne/v2/container"
    	 "fyne.io/fyne/v2/dialog"
    	 "fyne.io/fyne/v2/storage"
    	"fyne.io/fyne/v2/widget"
    	"github.com/flopp/go-findfont"
    	_ "io/ioutil"
    	"os"
    	"strings"
    )
    
    /*
    	用fyne实现简易版typora
    */
    
    func init() {
        
    	//设置中文字体:解决中文乱码问题
    	fontPaths := findfont.List()
    	for _, path := range fontPaths {
        
    		if strings.Contains(path, "msyh.ttf") || strings.Contains(path, "simhei.ttf") || strings.Contains(path, "simsun.ttc") || strings.Contains(path, "simkai.ttf") {
        
    			os.Setenv("FYNE_FONT", path)
    			break
    		}
    	}
    }
    
    type config struct {
        
    	EditWidget    *widget.Entry    //编辑框
    	PreviewWidget *widget.RichText //预览框【富文本】
    	CurrentFile   fyne.URI
    	SaveMenuItem  *fyne.MenuItem
    }
    
    var cfg config
    
    func main() {
        
    	a := app.New()
    	win := a.NewWindow("Markdown")
    	edit, preview := cfg.makeUI()
    	cfg.createMenuItems(win)
    	//布局选择左右布局，一边是编辑，一边是预览
    	win.SetContent(container.NewHSplit(edit, preview))
    
    	win.Resize(fyne.Size{
        Width: 800, Height: 500})
    	win.CenterOnScreen()
    	win.ShowAndRun()
    }
    
    //初始化界面
    func (app *config) makeUI() (*widget.Entry, *widget.RichText) {
        
    	edit := widget.NewMultiLineEntry()
    	preview := widget.NewRichTextFromMarkdown("")
    	app.EditWidget = edit
    	app.PreviewWidget = preview
    	edit.OnChanged = preview.ParseMarkdown
    
    	return edit, preview
    }
    
    //添加过滤器，只能打开.md结尾文件
    var filter = storage.NewExtensionFileFilter([]string{
        ".md", ".MD"})
    
    //创建主菜单
    func (app *config) createMenuItems(win fyne.Window) {
        
    	openMenuItem := fyne.NewMenuItem("open...", func() {
        })
    	//openMenuItem := fyne.NewMenuItem("open...", app.openFunc(win))
    
    	saveMenuItem := fyne.NewMenuItem("Save...", func() {
        })
    	//saveMenuItem := fyne.NewMenuItem("Save...", app.saveFunc(win))
    	app.SaveMenuItem = saveMenuItem
    	app.SaveMenuItem.Disabled = true
    	
    	//另存为
    	saveAsMenuItem := fyne.NewMenuItem("Save as...", app.saveAsFunc(win))
    
    	fileMenu := fyne.NewMenu("File", openMenuItem, saveMenuItem, saveAsMenuItem)
    
    	menu := fyne.NewMainMenu(fileMenu)
    
    	win.SetMainMenu(menu)
    }
    
    //【另存为】功能实现
    func (app *config) saveAsFunc(win fyne.Window) func() {
        
    	return func() {
        
    		saveDialog := dialog.NewFileSave(func(write fyne.URIWriteCloser, err error) {
        
    			if err != nil {
        
    				dialog.ShowError(err, win)
    				return
    			}
    
    			if write == nil {
        
    				//user canceled
    				return
    			}
    
    			if !strings.HasPrefix(strings.ToLower(write.URI().String()), ".md") {
        
    				dialog.ShowInformation("Error", "Please name your file with a .md extension!", win)
    				return
    			}
    
    			//save file
    			write.Write([]byte(app.EditWidget.Text))
    			app.CurrentFile = write.URI()
    			defer write.Close()
    
    			win.SetTitle(win.Title() + "-" + write.URI().Name())
    			app.SaveMenuItem.Disabled = false
    		}, win)
    		saveDialog.SetFileName("untitled.md")
    		saveDialog.SetFilter(filter)
    		saveDialog.Show()
    	}
    }

### 3 实现打开文件功能 ###

package main
    
    import (
    	"fyne.io/fyne/v2"
    	"fyne.io/fyne/v2/app"
    	"fyne.io/fyne/v2/container"
    	"fyne.io/fyne/v2/dialog"
    	"fyne.io/fyne/v2/storage"
    	"fyne.io/fyne/v2/widget"
    	"github.com/flopp/go-findfont"
    	"io/ioutil"
    	"os"
    	"strings"
    )
    
    /*
    	用fyne实现简易版typora
    */
    
    func init() {
        
    	//设置中文字体:解决中文乱码问题
    	fontPaths := findfont.List()
    	for _, path := range fontPaths {
        
    		if strings.Contains(path, "msyh.ttf") || strings.Contains(path, "simhei.ttf") || strings.Contains(path, "simsun.ttc") || strings.Contains(path, "simkai.ttf") {
        
    			os.Setenv("FYNE_FONT", path)
    			break
    		}
    	}
    }
    
    type config struct {
        
    	EditWidget    *widget.Entry    //编辑框
    	PreviewWidget *widget.RichText //预览框【富文本】
    	CurrentFile   fyne.URI
    	SaveMenuItem  *fyne.MenuItem
    }
    
    var cfg config
    
    func main() {
        
    	a := app.New()
    	win := a.NewWindow("Markdown")
    	edit, preview := cfg.makeUI()
    	cfg.createMenuItems(win)
    	//布局选择左右布局，一边是编辑，一边是预览
    	win.SetContent(container.NewHSplit(edit, preview))
    
    	win.Resize(fyne.Size{
        Width: 800, Height: 500})
    	win.CenterOnScreen()
    	win.ShowAndRun()
    }
    
    //初始化界面
    func (app *config) makeUI() (*widget.Entry, *widget.RichText) {
        
    	edit := widget.NewMultiLineEntry()
    	preview := widget.NewRichTextFromMarkdown("")
    	app.EditWidget = edit
    	app.PreviewWidget = preview
    	edit.OnChanged = preview.ParseMarkdown
    
    	return edit, preview
    }
    
    //添加过滤器，只能打开.md结尾文件
    var filter = storage.NewExtensionFileFilter([]string{
        ".md", ".MD"})
    
    //创建主菜单
    func (app *config) createMenuItems(win fyne.Window) {
        
    	//打开文件
    	openMenuItem := fyne.NewMenuItem("open...", app.openFunc(win))
    
    	saveMenuItem := fyne.NewMenuItem("Save...", func() {
        })
    	//saveMenuItem := fyne.NewMenuItem("Save...", app.saveFunc(win))
    	app.SaveMenuItem = saveMenuItem
    	app.SaveMenuItem.Disabled = true
    
    	//另存为
    	saveAsMenuItem := fyne.NewMenuItem("Save as...", app.saveAsFunc(win))
    
    	fileMenu := fyne.NewMenu("File", openMenuItem, saveMenuItem, saveAsMenuItem)
    
    	menu := fyne.NewMainMenu(fileMenu)
    
    	win.SetMainMenu(menu)
    }
    
    //【打开文件】功能
    func (app *config) openFunc(win fyne.Window) func() {
        
    	return func() {
        
    		openDialog := dialog.NewFileOpen(func(read fyne.URIReadCloser, err error) {
        
    			if err != nil {
        
    				dialog.ShowError(err, win)
    				return
    			}
    			if read == nil {
        
    				return
    			}
    			defer read.Close()
    			data, err := ioutil.ReadAll(read)
    			if err != nil {
        
    				dialog.ShowError(err, win)
    				return
    			}
    			app.EditWidget.SetText(string(data))
    			app.CurrentFile = read.URI()
    			win.SetTitle(win.Title() + "-" + read.URI().Name())
    			app.SaveMenuItem.Disabled = false
    		}, win)
    		//添加.md过滤器
    		openDialog.SetFilter(filter)
    		openDialog.Show()
    	}
    }
    
    //【另存为】功能实现
    func (app *config) saveAsFunc(win fyne.Window) func() {
        
    	return func() {
        
    		saveDialog := dialog.NewFileSave(func(write fyne.URIWriteCloser, err error) {
        
    			if err != nil {
        
    				dialog.ShowError(err, win)
    				return
    			}
    
    			if write == nil {
        
    				//user canceled
    				return
    			}
    
    			if !strings.HasPrefix(strings.ToLower(write.URI().String()), ".md") {
        
    				dialog.ShowInformation("Error", "Please name your file with a .md extension!", win)
    				return
    			}
    
    			//save file
    			write.Write([]byte(app.EditWidget.Text))
    			app.CurrentFile = write.URI()
    			defer write.Close()
    
    			win.SetTitle(win.Title() + "-" + write.URI().Name())
    			app.SaveMenuItem.Disabled = false
    		}, win)
    		saveDialog.SetFileName("untitled.md")
    		saveDialog.SetFilter(filter)
    		saveDialog.Show()
    	}
    }

### 4 实现保存功能 ###

package main
    
    import (
    	"fyne.io/fyne/v2"
    	"fyne.io/fyne/v2/app"
    	"fyne.io/fyne/v2/container"
    	"fyne.io/fyne/v2/dialog"
    	"fyne.io/fyne/v2/storage"
    	"fyne.io/fyne/v2/widget"
    	"github.com/flopp/go-findfont"
    	"io/ioutil"
    	"os"
    	"strings"
    )
    
    /*
    	用fyne实现简易版typora
    */
    
    func init() {
        
    	//设置中文字体:解决中文乱码问题
    	fontPaths := findfont.List()
    	for _, path := range fontPaths {
        
    		if strings.Contains(path, "msyh.ttf") || strings.Contains(path, "simhei.ttf") || strings.Contains(path, "simsun.ttc") || strings.Contains(path, "simkai.ttf") {
        
    			os.Setenv("FYNE_FONT", path)
    			break
    		}
    	}
    }
    
    type config struct {
        
    	EditWidget    *widget.Entry    //编辑框
    	PreviewWidget *widget.RichText //预览框【富文本】
    	CurrentFile   fyne.URI
    	SaveMenuItem  *fyne.MenuItem
    }
    
    var cfg config
    
    func main() {
        
    	a := app.New()
    	win := a.NewWindow("Markdown")
    	edit, preview := cfg.makeUI()
    	cfg.createMenuItems(win)
    	//布局选择左右布局，一边是编辑，一边是预览
    	win.SetContent(container.NewHSplit(edit, preview))
    
    	win.Resize(fyne.Size{
        Width: 800, Height: 500})
    	win.CenterOnScreen()
    	win.ShowAndRun()
    }
    
    //初始化界面
    func (app *config) makeUI() (*widget.Entry, *widget.RichText) {
        
    	edit := widget.NewMultiLineEntry()
    	preview := widget.NewRichTextFromMarkdown("")
    	app.EditWidget = edit
    	app.PreviewWidget = preview
    	edit.OnChanged = preview.ParseMarkdown
    
    	return edit, preview
    }
    
    //添加过滤器，只能打开.md结尾文件
    var filter = storage.NewExtensionFileFilter([]string{
        ".md", ".MD"})
    
    //创建主菜单
    func (app *config) createMenuItems(win fyne.Window) {
        
    	//打开文件
    	openMenuItem := fyne.NewMenuItem("open...", app.openFunc(win))
    
    	//保存文件
    	saveMenuItem := fyne.NewMenuItem("Save...", app.saveFunc(win))
    	app.SaveMenuItem = saveMenuItem
    	app.SaveMenuItem.Disabled = true
    
    	//另存为
    	saveAsMenuItem := fyne.NewMenuItem("Save as...", app.saveAsFunc(win))
    
    	fileMenu := fyne.NewMenu("File", openMenuItem, saveMenuItem, saveAsMenuItem)
    
    	menu := fyne.NewMainMenu(fileMenu)
    
    	win.SetMainMenu(menu)
    }
    
    
    //【保存文件】功能
    func (app *config) saveFunc(win fyne.Window) func() {
        
    	return func() {
        
    		if app.CurrentFile != nil {
        
    			write, err := storage.Writer(app.CurrentFile)
    			if err != nil {
        
    				dialog.ShowError(err, win)
    				return
    			}
    
    			write.Write([]byte(app.EditWidget.Text))
    			defer write.Close()
    		}
    	}
    }
    
    //【打开文件】功能
    func (app *config) openFunc(win fyne.Window) func() {
        
    	return func() {
        
    		openDialog := dialog.NewFileOpen(func(read fyne.URIReadCloser, err error) {
        
    			if err != nil {
        
    				dialog.ShowError(err, win)
    				return
    			}
    			if read == nil {
        
    				return
    			}
    			defer read.Close()
    			data, err := ioutil.ReadAll(read)
    			if err != nil {
        
    				dialog.ShowError(err, win)
    				return
    			}
    			app.EditWidget.SetText(string(data))
    			app.CurrentFile = read.URI()
    			win.SetTitle(win.Title() + "-" + read.URI().Name())
    			app.SaveMenuItem.Disabled = false
    		}, win)
    		//添加.md过滤器
    		openDialog.SetFilter(filter)
    		openDialog.Show()
    	}
    }
    
    //【另存为】功能实现
    func (app *config) saveAsFunc(win fyne.Window) func() {
        
    	return func() {
        
    		saveDialog := dialog.NewFileSave(func(write fyne.URIWriteCloser, err error) {
        
    			if err != nil {
        
    				dialog.ShowError(err, win)
    				return
    			}
    
    			if write == nil {
        
    				//user canceled
    				return
    			}
    
    			if !strings.HasPrefix(strings.ToLower(write.URI().String()), ".md") {
        
    				dialog.ShowInformation("Error", "Please name your file with a .md extension!", win)
    				return
    			}
    
    			//save file
    			write.Write([]byte(app.EditWidget.Text))
    			app.CurrentFile = write.URI()
    			defer write.Close()
    
    			win.SetTitle(win.Title() + "-" + write.URI().Name())
    			app.SaveMenuItem.Disabled = false
    		}, win)
    		saveDialog.SetFileName("untitled.md")
    		saveDialog.SetFilter(filter)
    		saveDialog.Show()
    	}
    }
    
    //安装打包程序
    //go install fyne.io/fyne/v2/cmd/fyne@latest
    //fyne package -appVersion 1.0.0 --name MarkDown -appID=.41234  -releas

### 5 全部代码 ###

package main
    
    import (
    	"fyne.io/fyne/v2"
    	"fyne.io/fyne/v2/app"
    	"fyne.io/fyne/v2/container"
    	"fyne.io/fyne/v2/dialog"
    	"fyne.io/fyne/v2/storage"
    	"fyne.io/fyne/v2/widget"
    	"github.com/flopp/go-findfont"
    	"io/ioutil"
    	"os"
    	"strings"
    )
    
    /*
    	用fyne实现简易版typora
    */
    
    func init() {
        
    	//设置中文字体:解决中文乱码问题
    	fontPaths := findfont.List()
    	for _, path := range fontPaths {
        
    		if strings.Contains(path, "msyh.ttf") || strings.Contains(path, "simhei.ttf") || strings.Contains(path, "simsun.ttc") || strings.Contains(path, "simkai.ttf") {
        
    			os.Setenv("FYNE_FONT", path)
    			break
    		}
    	}
    }
    
    type config struct {
        
    	EditWidget    *widget.Entry    //编辑框
    	PreviewWidget *widget.RichText //预览框【富文本】
    	CurrentFile   fyne.URI
    	SaveMenuItem  *fyne.MenuItem
    }
    
    var cfg config
    
    func main() {
        
    	a := app.New()
    	win := a.NewWindow("Markdown")
    	edit, preview := cfg.makeUI()
    	cfg.createMenuItems(win)
    	//布局选择左右布局，一边是编辑，一边是预览
    	win.SetContent(container.NewHSplit(edit, preview))
    
    	win.Resize(fyne.Size{
        Width: 800, Height: 500})
    	win.CenterOnScreen()
    	win.ShowAndRun()
    }
    
    //初始化界面
    func (app *config) makeUI() (*widget.Entry, *widget.RichText) {
        
    	edit := widget.NewMultiLineEntry()
    	preview := widget.NewRichTextFromMarkdown("")
    	app.EditWidget = edit
    	app.PreviewWidget = preview
    	edit.OnChanged = preview.ParseMarkdown
    
    	return edit, preview
    }
    
    //添加过滤器，只能打开.md结尾文件
    var filter = storage.NewExtensionFileFilter([]string{
        ".md", ".MD"})
    
    //创建主菜单
    func (app *config) createMenuItems(win fyne.Window) {
        
    	openMenuItem := fyne.NewMenuItem("open...", app.openFunc(win))
    
    	saveMenuItem := fyne.NewMenuItem("Save...", app.saveFunc(win))
    	app.SaveMenuItem = saveMenuItem
    	app.SaveMenuItem.Disabled = true
    	saveAsMenuItem := fyne.NewMenuItem("Save as...", app.saveAsFunc(win))
    
    	fileMenu := fyne.NewMenu("File", openMenuItem, saveMenuItem, saveAsMenuItem)
    
    	menu := fyne.NewMainMenu(fileMenu)
    
    	win.SetMainMenu(menu)
    }
    
    //【保存文件】功能
    func (app *config) saveFunc(win fyne.Window) func() {
        
    	return func() {
        
    		if app.CurrentFile != nil {
        
    			write, err := storage.Writer(app.CurrentFile)
    			if err != nil {
        
    				dialog.ShowError(err, win)
    				return
    			}
    
    			write.Write([]byte(app.EditWidget.Text))
    			defer write.Close()
    		}
    	}
    }
    
    //【打开文件】功能
    func (app *config) openFunc(win fyne.Window) func() {
        
    	return func() {
        
    		openDialog := dialog.NewFileOpen(func(read fyne.URIReadCloser, err error) {
        
    			if err != nil {
        
    				dialog.ShowError(err, win)
    				return
    			}
    			if read == nil {
        
    				return
    			}
    			defer read.Close()
    			data, err := ioutil.ReadAll(read)
    			if err != nil {
        
    				dialog.ShowError(err, win)
    				return
    			}
    			app.EditWidget.SetText(string(data))
    			app.CurrentFile = read.URI()
    			win.SetTitle(win.Title() + "-" + read.URI().Name())
    			app.SaveMenuItem.Disabled = false
    		}, win)
    		//添加.md过滤器
    		openDialog.SetFilter(filter)
    		openDialog.Show()
    	}
    }
    
    //【另存为】功能实现
    func (app *config) saveAsFunc(win fyne.Window) func() {
        
    	return func() {
        
    		saveDialog := dialog.NewFileSave(func(write fyne.URIWriteCloser, err error) {
        
    			if err != nil {
        
    				dialog.ShowError(err, win)
    				return
    			}
    
    			if write == nil {
        
    				//user canceled
    				return
    			}
    
    			if !strings.HasPrefix(strings.ToLower(write.URI().String()), ".md") {
        
    				dialog.ShowInformation("Error", "Please name your file with a .md extension!", win)
    				return
    			}
    
    			//save file
    			write.Write([]byte(app.EditWidget.Text))
    			app.CurrentFile = write.URI()
    			defer write.Close()
    
    			win.SetTitle(win.Title() + "-" + write.URI().Name())
    			app.SaveMenuItem.Disabled = false
    		}, win)
    		saveDialog.SetFileName("untitled.md")
    		saveDialog.SetFilter(filter)
    		saveDialog.Show()
    	}
    }
    
    //安装打包程序
    //go install fyne.io/fyne/v2/cmd/fyne@latest
    //fyne package -appVersion 1.0.0 --name MarkDown -appID=.41234  -releas

### 6 打包 ###

//安装打包程序
    go install fyne.io/fyne/v2/cmd/fyne@latest
    
    //执行打包命令
    fyne package -appVersion 1.0.0 --name MarkDown -appID=.41234  -release
    
    //运行app
    .\MarkDown

### 7 问题解决（fyne中文乱码问题） ###

//安装依赖库
    go get "github.com/flopp/go-findfont"

在main.go中添加初始化代码：

func init() {
        
    	//设置中文字体:解决中文乱码问题
    	fontPaths := findfont.List()
    	for _, path := range fontPaths {
        
    		if strings.Contains(path, "msyh.ttf") || strings.Contains(path, "simhei.ttf") || strings.Contains(path, "simsun.ttc") || strings.Contains(path, "simkai.ttf") {
        
    			os.Setenv("FYNE_FONT", path)
    			break
    		}
    	}
    }

### 8 发布 ###

> 对于mac系统的朋友来说，如果要想让打包之后的软件可以发给别人运行而不报错，则需要注册一个苹果开发者账号，并且使用付费版（一年大概100$），然后下载一个XCode，通过配置让XCode给我们打包好的软件签名。
> 
>  *  其他版本的os类似