塞特不在模特工作

Question

我正在尝试在学习Go时尝试理解MVC架构,并且我试图从控制器中更改模型中的值.

代码现在创建一个只保存字符串的模型,视图显示终端上的字符串,但控制器无法更改它(它获得用户输入没有任何问题).

现在我在终端上的文字是这样的:

Hello World!
asdf //my input
Hello World!

我想得到的输出将是这样的:

Hello World!
asdf //my input
asdf

这是我的文件:

model.go

package models

type IndexModel struct {
    Text string
}

func (m *IndexModel) InitModel() string {
    return m.Text
}

func (m *IndexModel) SetText(newText string) {
    m.Text = newText
}

view.go

package views

import "github.com/jufracaqui/mvc_template/app/models"

type IndexView struct {
    Model    models.IndexModel
}

func (v IndexView) Output() string {
    return v.Model.Text
}

controller.go

package controllers

import "github.com/jufracaqui/mvc_template/app/models"

type IndexController struct {
    Model models.IndexModel
}

func (c IndexController) ChangeText(userInput string) {
    c.Model.SetText(userInput)
}

main.go:

package main

import (
    "bufio"
    "os"

    "fmt"

    "github.com/jufracaqui/mvc_template/app/controllers"
    "github.com/jufracaqui/mvc_template/app/models"
    "github.com/jufracaqui/mvc_template/app/views"
)

func main() {
    handleIndex()
}

func handleIndex() {
    model := models.IndexModel{
        "Hello World!",
    }

    controller := controllers.IndexController{
        model,
    }

    viewIndex := views.IndexView{
        model,
    }

    fmt.Println(viewIndex.Model.Text)

    reader := bufio.NewReader(os.Stdin)
    text, _ := reader.ReadString('\n')
    controller.ChangeText(text)
    fmt.Println(viewIndex.Model.Text)
}

编辑: @JimB回答后我的代码如何结束:

model.go:

package models

type IndexModel struct {
    Text string
}

func (m *IndexModel) InitModel() string {
    return m.Text
}

view.go:

package views

import "github.com/jufracaqui/mvc_template/app/models"

type IndexView struct {
    Model    *models.IndexModel
}

func (v IndexView) Output() string {
    return v.Model.Text
}

controller.go:

package controllers

import "github.com/jufracaqui/mvc_template/app/models"

type IndexController struct {
    Model *models.IndexModel
}

func (c IndexController) ChangeText(userInput string) {
    c.Model.Text = userImput
}

main.go:

package main

import (
    "bufio"
    "os"

    "fmt"

    "github.com/jufracaqui/mvc_template/app/controllers"
    "github.com/jufracaqui/mvc_template/app/models"
    "github.com/jufracaqui/mvc_template/app/views"
)

func main() {
    handleIndex()
}

func handleIndex() {
    model := models.IndexModel{
        "Hello World!",
    }

    m := &model

    controller := controllers.IndexController{
        m,
    }

    viewIndex := views.IndexView{
        m,
    }

    fmt.Println(viewIndex.Model.Text)

    reader := bufio.NewReader(os.Stdin)
    text, _ := reader.ReadString('\n')
    controller.ChangeText(text)
    fmt.Println(viewIndex.Model.Text)
}

Answer 1

IndexController.ChangeText需要一个指针接收器,或者IndexController.Model需要一个指针.您正在调用SetText该SetText值的副本.

如果你期望事物是可变的,那么始终如一地使用指向结构的指针要容易得多,并且当你真正需要时,使显式的struct值成为异常.