根据swagger.json生成flutter model，暂无空安全支持

一般的服务端类型都有泛型支持，对于flutter来说虽然也支持泛型，但是在序列化这里却始终存在问题,flutter不允许用反射，对于flutter项目的开发来说除了画页面，可能最烦人的就是跟服务端打交道的时候对对象创建以及序列化，虽然目前网上也有通过json to dart之类的在线工具根据json生成model,但一个项目中那么多类，都这么做一遍太费劲，在有上下级类的情况下需要手动去一个个的调整，烦人，于是写了一个小工具通过 swagger.json 生成flutter model。

1，首先在C#中 我们知道可以的可以生成代码的有razor模板和T4模板，我是基于.net 5开发的于是就顺其自然的使用了当下流行的razor模板来生成代码

在代码引入类库RazorEngine.NetCore

 var config = new TemplateServiceConfiguration();
config.Language = Language.CSharp; // CSharp.NET as template language.
config.AllowMissingPropertiesOnDynamic = true;
config.CachingProvider = new DefaultCachingProvider(t => { });
config.EncodedStringFactory = new HtmlEncodedStringFactory(); // Html encoding.
config.Debug = false;
var service = RazorEngineService.Create(config);
var enummodel= File.ReadAllText("fluttermodel.cshtml");
var  result = Engine.Razor.RunCompile(enummodel, "fluttermodel", null, modelsinfo[i]);

result 就是根据模板生成的最终代码，代码量非常少，代码生成中最主要的地方在于传入template的model，model中需要定义一个dart类中需要用到的所有信息，

2 template fluttermodel.cshtml

@using flutter_model_genrate_swagger;
@using System.Linq;
@using System.Text;
@{
    var modeldes = "";
    if (!string.IsNullOrEmpty(Model.Description))
    {
        modeldes = string.Concat("///", Model.Description);
    }
    var modelparams = "";//参数

    var package = "";
    if (Model.Package != null && Model.Package.Count > 0)
    {
        foreach (var pk in Model.Package)
        {
            package += string.Concat("import '", pk, ".dart';
");
        }
    }
}


@Raw(package)
@Raw(modeldes)
class @Model.Name {
@foreach (var proptey in Model.ModelPropties)
{
    if (!string.IsNullOrEmpty(proptey.Description))
    { 
        @Raw(string.Concat("///", proptey.Description,"
"))   
    }
    @switch (proptey.Type)
    {
        case "array":
            @{
                string type = string.Concat("List<", @proptey.SubType, ">");
            }
            @Raw(type) @proptey.LowCaseName@(";")
            break;
        case "integer":
            @("int ") @proptey.LowCaseName@(";")
            break;
        case "string":
            @("String ") @proptey.LowCaseName@(";")
            break;
        case "boolean":
            @("bool ") @proptey.LowCaseName@(";")
            break;
        case "number":
            if (proptey.Format == "double")
            {
                @("double ") @proptey.LowCaseName@(";")
            }
            else
            {
                @Raw("///类型不确定")
                @("double ") @proptey.LowCaseName@(";")
            }
            break;
        default:
            @Raw(proptey.Type + " ")@proptey.LowCaseName@(";")
            break;
    }
    @Raw("
");
    if (string.IsNullOrEmpty(modelparams))
    {
        modelparams += string.Concat("this.", proptey.LowCaseName);
    }
    else
    {
        modelparams += string.Concat(",this.", proptey.LowCaseName);
    }
}
@Model.Name @("({")@modelparams@("});")
@Raw("
")
@Model.Name@Raw(".fromJson(Map<String, dynamic> json) {") @Raw("
")
@foreach (var proptey in Model.ModelPropties)
{
    @switch (proptey.Type)
    {
        case "array":
            @{
                string type = string.Concat("List<", @proptey.SubType, ">");
            }
            @Raw("if (json['")@proptey.Name@Raw("'] != null) {")@Raw("
")
            @proptey.LowCaseName@Raw("=[];")@Raw("
")
            @Raw("json['")@proptey.Name@Raw("'].forEach((v) {")@Raw("
")
            @if (proptey.SubTypeDes == "baseType")
            {
                @proptey.LowCaseName@(".add(v);")@Raw("
")
            }
            else
            {
                @proptey.LowCaseName@(".add(")@proptey.SubType@Raw(".fromJson(v));")@Raw("
")
            }
            @Raw("});
")
            @Raw(" } else {
")
            @proptey.LowCaseName@Raw("=[];
")
            @Raw("}
")
            break;
        case "integer":
        case "string":
        case "boolean":
        case "number":
            @proptey.LowCaseName@("=")@Raw("json['") @proptey.Name@Raw("'];")
            break;
        default:
            //判断类型的
            if (proptey.TypeDes == "object")
            {
                @proptey.LowCaseName@Raw("=json['")@proptey.Name@Raw("']!=null? ")@proptey.Type@Raw(".fromJson(json['")@proptey.Name@Raw("']) : null;
")
            }
            else
            {
                @proptey.LowCaseName@("=")@Raw("json['") @proptey.Name@Raw("'];")
            }
            break;
    }
    @Raw("
");
}
}
@Raw("Map<String, dynamic> toJson() { 
")
@Raw("final Map<String, dynamic> data = new Map<String, dynamic>();
")
@foreach (var proptey in Model.ModelPropties)
{
    switch (proptey.Type)
    {
        case "integer":
        case "string":
        case "boolean":
        case "number":
            @Raw("data['")@proptey.Name@Raw("'] = this.")@proptey.LowCaseName@Raw(";
")
            break;
        case "array":
            //data['Data'] = this.data.map((v) => v.toJson()).toList();
            @Raw("if (this.")@proptey.LowCaseName@Raw(" != null) { 
")

            @if (proptey.SubTypeDes == "baseType")
            {
                @Raw("data['")@proptey.Name@Raw("'] = this.")@proptey.LowCaseName@Raw(".toList();
")
            }
            else
            {
                @Raw("data['")@proptey.Name@Raw("'] = this.")@proptey.LowCaseName@Raw(".map((v) => v.toJson()).toList();
")
            }
            @Raw("}
")

            break;//普通对象
        default:
            if (proptey.TypeDes == "object")
            {

                @Raw("if (this.")@proptey.LowCaseName@Raw(" != null) { 
")
                @Raw("data['")@proptey.Name@Raw("'] = this.")@proptey.LowCaseName@Raw(".toJson();
")
                @Raw("}
")
            }
            else
            {
                @Raw("data['")@proptey.Name@Raw("'] = this.")@proptey.LowCaseName@Raw(";
")
            }
            break;
    }
}
@Raw("return data;
")
@Raw("}
")

}

3 传入template的类定义

public enum ModelInfoType
    { 
        Obj,
        Enum
    }
    public class ModelInfo
    {
        public ModelInfo() {
            ModelPropties = new List<ModelPropty>();
        }
        public ModelInfoType Type { get; set; }
        public string Name { get; set; }
        public string Description { get; set; }
        public List<ModelPropty> ModelPropties { get; set; }

        public string LowCaseName
        {
            get
            {
                if (string.IsNullOrEmpty(Name) || Name.Length < 2)
                {
                    return Name;
                }
                else
                { 
                    return Name.Substring(0, 1).ToLower() + Name.Substring(1);
                }
            }
        }
        public List<string> Package
        {
            get
            {
                if (this.ModelPropties.Count == 0)
                {
                    return null;
                }
                else
                {
                    var result = new List<string>();
                    foreach (var item in ModelPropties)
                    {
                        if (item.Type == "array")//包含arry
                        {
                            if (string.IsNullOrEmpty(item.SubType))
                            {
                                if (!ServiceAgent.BaseTypes.Contains(item.Type))
                                {
                                    result.Add(item.Type.Substring(0, 1).ToLower() + item.Type.Substring(1));
                                }
                               
                            }
                            else
                            {
                                if (!ServiceAgent.BaseTypes.Contains(item.SubType.ToLower()))
                                {
                                    result.Add(item.SubType.Substring(0, 1).ToLower() + item.SubType.Substring(1));
                                }
                            }
                        }
                        else if (!ServiceAgent.BaseTypes.Contains(item.Type))//基础类型外
                        {
                            result.Add(item.Type.Substring(0, 1).ToLower() + item.Type.Substring(1));
                        }
                    }
                    return result;
                }
            }
        }


    }

    public class ModelPropty
    { 
        public string Name { get; set; }
        /// <summary>
        /// List<....> | 具体类型
        /// </summary>
        public string Type { get; set; }
        /// <summary>
        /// 如果是arry，这里是arry的子类，
        /// </summary>
        public string SubType { get; set; }
        /// <summary>
        /// 子类描述
        /// </summary>
        public string SubTypeDes { get; set; }
        /// <summary>
        /// 类型描述
        /// </summary>
        public string TypeDes { get; set; }
        public string Format { get; set; }

        public string Description { get; set; }

        public string LowCaseName
        {
            get
            {
                if (string.IsNullOrEmpty(Name)|| Name.Length<2)
                {
                    return Name;
                }
                else
                {
                    return Name.Substring(0, 1).ToLower() + Name.Substring(1);
                }
            }
        }
    }

4 接下去的事情就简单了，把swagger.json下载到本地，用system.text.json解析拿到swagger.json中的所有model,挨个生成

5 最后调用flutter format {文件夹位置} 将所有生成的model类格式化一遍，如果这里发生错误，手动执行以下命令就大功告成了。

6 最后附上项目地址： https://gitee.com/zzf_1/flutter-model-genrate-swagger

release版本下载地址：https://gitee.com/zzf_1/flutter-model-genrate-swagger/tags 【release版本稍微有点大，但是release版本不需要.net环境，对于专职flutter的开发人员来说这个应该会比较有用】