一个用go写的模拟mp3文字界面播放程序

痛定思痛。 2022-01-30 10:29 139阅读 0赞

这里的技巧在于学习如何定义数据结构，更新数据结构，在哪里用指针或是地址来更新。

manger.go

package library
    
    import "errors"
    
    type MusicEntry struct {
    	Id     string
    	Name   string
    	Artist string
    	Source string
    	Type   string
    }
    
    type MusicManager struct {
    	musics []MusicEntry
    }
    
    func NewMusicManager() *MusicManager {
    	return &MusicManager{make([]MusicEntry, 0)}
    }
    
    func (m *MusicManager) Len() int {
    	return len(m.musics)
    }
    
    func (m *MusicManager) Get(index int) (music *MusicEntry, err error) {
    	if index < 0 || index >= len(m.musics) {
    		return nil, errors.New("Index out of range.")
    	}
    	return &m.musics[index], nil
    }
    
    func (m *MusicManager) Find(name string) *MusicEntry {
    	if len(m.musics) == 0 {
    		return nil
    	}
    
    	for _, m := range m.musics {
    		if m.Name == name {
    			return &m
    		}
    	}
    	return nil
    }
    
    func (m *MusicManager) Add(music *MusicEntry) {
    	m.musics = append(m.musics, *music)
    }
    
    func (m *MusicManager) Remove(index int) *MusicEntry {
    	if index < 0 || index >= len(m.musics) {
    		return nil
    	}
    
    	removedMusic := &m.musics[index]
    
    	if index < len(m.musics)-1 {
    		m.musics = append(m.musics[:index-1], m.musics[index+1:]...)
    	} else if index == 0 {
    		m.musics = make([]MusicEntry, 0)
    	} else {
    		m.musics = m.musics[:index-1]
    	}
    
    	return removedMusic
    }
    
    func (m *MusicManager) RemoveByName(name string) *MusicEntry {
    	if len(m.musics) == 0 {
    		return nil
    	}
    
    	for _, m := range m.musics {
    		if m.Name == name {
    			return &m
    		}
    	}
    	return nil
    }

play.go

package mp
    
    import "fmt"
    
    type Player interface {
    	Play(source string)
    }
    
    func Play(source, mtype string) {
    	var p Player
    
    	switch mtype {
    	case "MP3":
    		p = &MP3Player{}
    	case "WAV":
    		p = &WAVPlayer{}
    	default:
    		fmt.Println("Unsupported music type", mtype)
    		return
    	}
    	p.Play(source)
    }

mp3.go

package mp
    
    import (
    	"fmt"
    	"time"
    )
    
    type MP3Player struct {
    	stat     int
    	progress int
    }
    
    func (p *MP3Player) Play(source string) {
    	fmt.Println("Playing MP3 music", source)
    
    	p.progress = 0
    
    	for p.progress < 100 {
    		time.Sleep(100 * time.Millisecond)
    		fmt.Print(".")
    		p.progress += 10
    	}
    
    	fmt.Println("\nFinished playing", source)
    }

mplayer.go

// SMP project main.go
    package main
    
    import (
    	"bufio"
    	"fmt"
    	"os"
    	"strconv"
    	"strings"
    
    	"SMP/mlib"
    	"SMP/mp"
    )
    
    var lib *library.MusicManager
    var id int = 1
    var ctrl, signal chan int
    
    func handleLibCommands(tokens []string) {
    	switch tokens[1] {
    	case "list":
    		for i := 0; i < lib.Len(); i++ {
    			e, _ := lib.Get(i)
    			fmt.Println(i+1, ":", e.Name, e.Artist, e.Source, e.Type)
    		}
    	case "add":
    		{
    			if len(tokens) == 6 {
    				id++
    				lib.Add(&library.MusicEntry{strconv.Itoa(id),
    					tokens[2], tokens[3], tokens[4], tokens[5]})
    			} else {
    				fmt.Println("USAGE: lib add <name><artist><source><type>")
    			}
    		}
    	case "remove":
    		if len(tokens) == 3 {
    			lib.RemoveByName(tokens[2])
    		} else {
    			fmt.Println("USAGE: lib remove <name>")
    		}
    	default:
    		fmt.Println("Unrecognized lib command: ", tokens[1])
    	}
    }
    
    func handlePlayCommand(tokens []string) {
    	if len(tokens) != 2 {
    		fmt.Println("USAGE: play <name>")
    		return
    	}
    
    	e := lib.Find(tokens[1])
    	if e == nil {
    		fmt.Println("The music ", tokens[1], " does not exist.")
    		return
    	}
    
    	mp.Play(e.Source, e.Type)
    }
    
    func main() {
    	fmt.Println(`
    		Enter following commands to control the player:
    		lib list -- View the existing music lib
    		lib add <name><artist><source><type> -- Add a music to the music lib
    		lib remove <name> -- Remove the specified music from the lib
    		play <name> -- Play the specified music
    	`)
    
    	lib = library.NewMusicManager()
    	r := bufio.NewReader(os.Stdin)
    
    	for {
    		fmt.Print("Enter command-> ")
    		rawLine, _, _ := r.ReadLine()
    		line := string(rawLine)
    		if line == "q" || line == "e" {
    			break
    		}
    		tokens := strings.Split(line, " ")
    		if tokens[0] == "lib" {
    			handleLibCommands(tokens)
    		} else if tokens[0] == "play" {
    			handlePlayCommand(tokens)
    		} else {
    			fmt.Println("Unrecognized command: ", tokens[0])
    		}
    	}
    }

![img_b47a52ab2bf54d4bd5e968ce7989fb7e.png][]

[img_b47a52ab2bf54d4bd5e968ce7989fb7e.png]: /images/20220130/72420eb8945a4475a59b4f87e8c1d5f7.png