WinForm（十一）用户控件

winform+api是一种对接数据模式，在本例中，为了方便，开发两个天生具有与后台api对接的用例控件，并且把他们封闭成单独控件，以供多次使用。

提示：此实例不是生产使用，仅作演示，有不完善地方，重点关注流程和自定义控件。

本例为API Server，用户控件项目，使用控件项目。.

API Server端：

api端主要是根据提交上来的请求，组装成一个sql，查询一个内存sqlite数据库（请注意这里没有做sql注入处理）

using Dapper;using Microsoft.Data.Sqlite;using System.Data;using System.Data.Common;using System.Net;using System.Text;using System.Text.Encodings.Web;using System.Text.Unicode;using System.Web;
var builder = WebApplication.CreateBuilder(args);
var connection = new SqliteConnection("Data Source=InMemorySample;Mode=Memory;Cache=Shared");
await InitDataAsync();async Task InitDataAsync(){    await connection.OpenAsync();    await connection.ExecuteAsync("create table type(ID INTEGER primary key,Name text,Category INTEGER);");    await connection.ExecuteAsync("insert into main.type(ID,Name,Category) values(1,'AliPay',1),(2,'MiroPay',1),(3,'PayPay',2);");    await connection.ExecuteAsync("create table [order](ID INTEGER primary key,Name text,Price real,Quantity integer);");    await connection.ExecuteAsync("insert into [order](ID,Name,Price,Quantity) values(1,'产品A',21.15,12),(2,'产品B',32.45,23),(3,'产品C',43.45,23);");}builder.Services.AddSingleton<IDbConnection>(connection);builder.Services.AddResponseCaching();builder.Services.AddSingleton<IParameService, ParameService>();
var app = builder.Build();
app.UseResponseCaching();app.Use(async (context, next) =>{    context.Response.GetTypedHeaders().CacheControl =        new Microsoft.Net.Http.Headers.CacheControlHeaderValue()        {            Public = true,            MaxAge = TimeSpan.FromHours(1)        };    context.Response.Headers[Microsoft.Net.Http.Headers.HeaderNames.Vary] =        new string[] { "Accept-Encoding" };    await next();});
app.MapGet("/parame/{dataSource}", async (IParameService parameService, string dataSource, string fields, string conditions) =>{    var list = await parameService.GetParamesAsync(dataSource, fields, conditions);    return TypedResults.Json(list, new System.Text.Json.JsonSerializerOptions { PropertyNameCaseInsensitive = false });});app.Run();
public interface IParameService{    Task<IEnumerable<dynamic>> GetParamesAsync(string dataSource, string fields, string conditions);}public class ParameService : IParameService{    private readonly ILogger<ParameService> _logger;    private readonly IDbConnection _db;    public ParameService(ILogger<ParameService> logger, IDbConnection db)    {        _logger = logger;        _db = db;    }    public async Task<IEnumerable<dynamic>> GetParamesAsync(string dataSource, string fields, string conditions)    {          var sql = $"select {fields} from [{dataSource}]";        if (conditions != null && conditions.Length > 0)        {            var whereBuilder = new StringBuilder(" where ");            var conditionArr = conditions.Split(new string[] { "(", "),(", ")" }, StringSplitOptions.RemoveEmptyEntries);            foreach (var condition in conditionArr)            {                var arr = condition.Split(new string[] { "," }, StringSplitOptions.RemoveEmptyEntries);                whereBuilder.Append($" {arr[0]} {arr[1]} '{arr[2]}' and");            }            sql += whereBuilder.ToString().Substring(0, whereBuilder.Length - 3);        }        _logger.LogInformation(sql);        return await _db.QueryAsync<dynamic>(sql);       }}

用户控件端：

用户控件有一个公共部分，分别处理两类控件ListControl和DataGridView控件，思路都是从控件上拿到相应的属性数据，然后组装http请求，取回数据，绑定到控件上。

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing.Design;using System.Linq;using System.Net.Http;using System.Security.Policy;using System.Text;using System.Text.Json;using System.Threading.Tasks;using System.Web;
namespace GSWControls{    public static class ControlExpand    {        static HttpClient _httpClient = new HttpClient();        public static async Task DBControlInit(this ListControl control, string url, string dataSourceName, List<DBCondition>? conditions)        {            if (!control.IsAncestorSiteInDesignMode)            {                if (!string.IsNullOrWhiteSpace(url) && !string.IsNullOrWhiteSpace(dataSourceName) && !string.IsNullOrWhiteSpace(control.DisplayMember) && !string.IsNullOrWhiteSpace(control.ValueMember))                {                    url = $"{url.TrimEnd('/', '\\')}/{dataSourceName}?fields={Uri.EscapeDataString(control.ValueMember)},{Uri.EscapeDataString(control.DisplayMember)}";                    if (conditions != null && conditions.Count > 0)                    {                        var arr = conditions.Select(s => $"({s.Name},{s.Symbol},{s.Value})").ToArray();                        url += "&conditions=" + Uri.EscapeDataString(string.Join(',', arr));                    }                    var content = await _httpClient.GetStringAsync(url);                    var table = JsonToDataTable(content);                    control.DataSource = table;                }            }        }        static DataTable JsonToDataTable(string json)        {            var table = new DataTable();            var list = JsonSerializer.Deserialize<IList<Dictionary<string, dynamic>>>(json);            var columns = list?.First().Select(d => d.Key);            if (list != null && columns != null)            {                foreach (var item in columns)                {                    table.Columns.Add(item);                }                foreach (var item in list)                {                    table.Rows.Add(item.Values.ToArray());                }            }            return table;        }
        public static async Task DBGridInit(this DataGridView control, string url, string dataSourceName, List<DBCondition>? conditions)        {            if (!control.IsAncestorSiteInDesignMode)            {                if (!string.IsNullOrWhiteSpace(url) && !string.IsNullOrWhiteSpace(dataSourceName) && control.Columns.Count > 0)                {                    var fieldList = new List<string>();                    foreach (DataGridViewColumn column in control.Columns)                    {                        fieldList.Add(column.DataPropertyName);                    }                    url = $"{url.TrimEnd('/', '\\')}/{dataSourceName}?fields={Uri.EscapeDataString(string.Join(',', fieldList))}";                    if (conditions != null && conditions.Count > 0)                    {                        var arr = conditions.Select(s => $"({s.Name},{s.Symbol},{s.Value})").ToArray();                        url += "&conditions=" + Uri.EscapeDataString(string.Join(',', arr));                    }
                    var content = await _httpClient.GetStringAsync(url);                    var table = JsonToDataTable(content);                    control.DataSource = table;                }            }        }    }
    public class DBCondition    {        [Browsable(true)]        [Description("查询条件名称"), Category("数据"), DefaultValue("")]        [DisplayName]        public string? Name { get; set; }        [Browsable(true)]        [Description("条件符号"), Category("数据"), DefaultValue("")]        public string? Symbol { get; set; }        [Browsable(true)]        [Description("查询条件值"), Category("数据"), DefaultValue("")]        public string? Value { get; set; }    }}

DBComBox控件：

using System;using System.Collections.Generic;using System.ComponentModel;using System.Linq;using System.Text;using System.Threading.Tasks;
namespace GSWControls{    [ToolboxItem(true)]    [ToolboxBitmap(typeof(DBComBox), "gcom.png")]    public class DBComBox : ComboBox    {               [Browsable(true)]        [Description("后端Url"), Category("远程数据"), DefaultValue("")]        public string? Url { get; set; }
        [Browsable(true)]        [Description("访问Url后端数据源名称"), Category("远程数据"), DefaultValue("")]        public string? DataSourceName { get; set; }
        [Browsable(true)]        [Description("查询数据源条件参数"), Category("远程数据"), DefaultValue("")]        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]        public List<DBCondition>? Conditions { get; set; } = new List<DBCondition>();
        protected async override void CreateHandle()        {            base.CreateHandle();            if (!string.IsNullOrWhiteSpace(Url) && !string.IsNullOrWhiteSpace(DataSourceName) && Conditions != null)            {                await this.DBControlInit(Url, DataSourceName, Conditions);            }        }    }}

DBDataGridView控件：

using System;using System.Collections.Generic;using System.ComponentModel;using System.Linq;using System.Text;using System.Threading.Tasks;
namespace GSWControls{    [ToolboxItem(true)]    [ToolboxBitmap(typeof(DBDataGridView), "ggrid.png")]    public class DBDataGridView : DataGridView    {                [Browsable(true)]        [Description("后端Url"), Category("远程数据"), DefaultValue("")]        public string? Url { get; set; }                    [Browsable(true)]        [Description("访问Url后端数据源名称"), Category("远程数据"), DefaultValue("")]        public string? DataSourceName { get; set; }
        [Browsable(true)]        [Description("查询数据源条件参数"), Category("远程数据"), DefaultValue("")]        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]        public List<DBCondition>? Conditions { get; set; } = new List<DBCondition>();
        protected async override void CreateHandle()        {            base.CreateHandle();            if (!string.IsNullOrWhiteSpace(Url) && !string.IsNullOrWhiteSpace(DataSourceName) && Conditions != null)            {                await this.DBGridInit(Url, DataSourceName, Conditions);            }        }    }}