bh002- Blazor hybrid / Maui 使用ORM和数据库快速教程

news2024/9/20 14:46:37

接上篇 bh002- Blazor hybrid / Maui 保存设置快速教程

源码

10. 添加引用

Index.razor.cs

添加引用

using FreeSql.DataAnnotations;
#if WINDOWS
using Windows.Storage;
#endif

11. 简单使用freesql ORM 初始化数据,添加数据

public partial class Index
{

    [DisplayName("用户名")]
    [Required(ErrorMessage = "请输入用户名")]
    public string NewUsername { get; set; }
    List<Users> UserList { get; set; }
    string Dbpath { get; set; }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender)
            {
                StateHasChanged();
            }

            //添加这句
            await OrmTestAsync();
        }
    }


    async Task OrmTestAsync()
    {
#if WINDOWS
        string dbpath = Path.Combine(ApplicationData.Current.LocalFolder.Path, "hybrid.db");
#elif ANDROID || IOS || MACCATALYST
        string dbpath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Personal), "hybrid.db");
#else
        string dbpath = "hybrid.db";
#endif 

        Fsql = new FreeSql.FreeSqlBuilder()
             .UseConnectionString(FreeSql.DataType.Sqlite, $"Data Source={dbpath};")
             //调试sql语句输出
             .UseMonitorCommand(cmd => System.Console.WriteLine(cmd.CommandText + Environment.NewLine))
             //自动同步实体结构到数据库，FreeSql不会扫描程序集，只有CRUD时才会生成表。
             .UseAutoSyncStructure(true)
            .UseNoneCommandParameter(true)
            .Build();

        if (Fsql.Select<Users>().Count() < 1)
        {
            var itemList = Users.GenerateDatas();
            Fsql.Insert<Users>().AppendData(itemList).ExecuteAffrows();
        }

        UserList= await Fsql.Select<Users>().ToListAsync();

        Dbpath = dbpath;

        StateHasChanged();

    }

    async Task Add()
    {
        Fsql.Insert(new Users() { Username = NewUsername , FullName = "试用用户"}).ExecuteAffrows();

        UserList = await Fsql.Select<Users>().ToListAsync();

        StateHasChanged();
    }

}

12. 用户表实体类

源码工程为了简单起见,都暂时放在同一个文件里面.


/// <summary>
/// 用户表
/// </summary>
public class Users
{

    [Column(IsIdentity = true, IsPrimary = true)]
    [DisplayName("序号")]
    public Guid UserID { get; set; }

    //[Column(IsPrimary = true)]
    [DisplayName("用户名")]
    [Required]
    public string Username { get; set; }

    [DisplayName("真实姓名")]
    [Required]
    public string FullName { get; set; }

    [DisplayName("启用")]
    public bool? Enable { get; set; } = false;

    public static List<Users> GenerateDatas()
    {
        var ItemList = new List<Users>()
        {
            new Users {
                Username = "root" ,
                FullName="超级用户",
                Enable =false
                },
            new Users {
                Username = "admin" ,
                FullName="管理员",
                Enable =true
                },
            new Users {
                Username = "guest" ,
                FullName="游客",
                Enable =false
                },
            new Users {
                Username = "user" ,
                FullName="正式用户",
                Enable =true
                },
        };

        return ItemList;
    }
}

13. 列表数据

Index.razor

<hr />

添加用户:
<InputText @bind-Value="NewUsername" />
<button @onclick="Add">添加</button>


@if (UserList != null)
{
    @foreach (var item in UserList)
    {
        <p><b>@item.FullName</b> <h5>@item.Username</h5></p>
    }
}

Dbpath: @Dbpath