建立BasePagedListVM主要有以下幾部

1. 定義繼承自BasePagedListVM的類(lèi)，將關(guān)聯(lián)的Model作為泛型變量

2. 重寫(xiě)GetSearchQuery函數(shù)，將查詢語(yǔ)句和邏輯寫(xiě)在這個(gè)函數(shù)里

3. 重寫(xiě)InitGridHeader函數(shù)，這個(gè)函數(shù)定義列表顯示的列

4. 重寫(xiě)InitGridAction函數(shù)，這個(gè)函數(shù)定義列表中需要出現(xiàn)的操作按鈕

下面以學(xué)校模型為例，展示如何編寫(xiě)一個(gè)簡(jiǎn)單的ListVM，學(xué)校模型的定義可以參考第一個(gè)模塊

public class SchoolListVM : BasePagedListVM<School, BaseSearcher>
{
    protected override List<GridAction> InitGridAction()
    {
        return new List<GridAction>
        {
            this.MakeStandardAction("School", GridActionStandardTypesEnum.Create, "新建","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.Edit, "修改","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.Delete, "刪除", "",dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.Details, "詳細(xì)","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.BatchEdit, "批量修改","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.BatchDelete, "批量刪除","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.Import, "導(dǎo)入","", dialogWidth: 800),
            this.MakeStandardExportAction(null,false,ExportEnum.Excel)
        };
    }
    protected override IEnumerable<IGridColumn<School>> InitGridHeader()
    {
        return new List<GridColumn<School>>{
            this.MakeGridHeader(x => x.SchoolCode),
            this.MakeGridHeader(x => x.SchoolName),
            this.MakeGridHeader(x => x.SchoolType),
            this.MakeGridHeaderAction(width: 200)
        };
    }
    public override IOrderedQueryable<School> GetSearchQuery()
    {
        var query = DC.Set<School>().OrderBy(x => x.ID);
        return query;
    }
}
    

上面代碼建立了一個(gè)簡(jiǎn)單的ListVM，它沒(méi)有任何搜索條件，默認(rèn)每頁(yè)20行查詢所有School的數(shù)據(jù)，并使用輸出列表同樣的邏輯來(lái)完成導(dǎo)出Excel。同時(shí)它定義了新建，修改等按鈕

RecordsPerPage屬性可以設(shè)置每頁(yè)行數(shù)，默認(rèn)是20行，NeedPage屬性可以設(shè)定是否要進(jìn)行分頁(yè)

MakeStandardExportAction的作用是在列表上生成一個(gè)導(dǎo)出按鈕

MakeGridHeaderAction的作用是在列表上增加一個(gè)操作列，操作列中出現(xiàn)的按鈕是在InitGridAction中定義的所有ShowInRow為true的動(dòng)作。當(dāng)使用MakeStandardAction創(chuàng)建默認(rèn)動(dòng)作時(shí)，修改，刪除和詳細(xì)都是每行顯示的

在Controller中使用BasePagedListVM的步驟也是一目了然，請(qǐng)看下面的例子

#region 搜索
[ActionDescription("搜索")]
public ActionResult Index()
{
    var vm = CreateVM<SchoolListVM>();
    return PartialView(vm);
}
#endregion
    

必須使用CreateVM函數(shù)來(lái)創(chuàng)建ViewModel，而不要直接new。CreateVM函數(shù)會(huì)將當(dāng)前Controller的Session，ModelState等信息傳遞給VM，并進(jìn)行一些框架內(nèi)部的操作

上面的例子并沒(méi)有任何搜索條件，真實(shí)場(chǎng)景中這種情況是很少的，要在列表中加入搜索條件，有兩個(gè)步驟

1. 定義一個(gè)繼承自BaseSearcher的類(lèi)，將搜索條件作為類(lèi)的屬性，并把ListVM類(lèi)的第二個(gè)泛型變量設(shè)定為這個(gè)Searcher

2. 在GetSearchQuery函數(shù)中使用Searcher的數(shù)據(jù)來(lái)編寫(xiě)查詢語(yǔ)句

比如建立一個(gè)下面的Searcher用于搜索學(xué)校數(shù)據(jù)

public class SchoolSearcher : BaseSearcher
{
    [Display(Name = "學(xué)校編碼")]
    public String SchoolCode { get; set; }
    [Display(Name = "學(xué)校名稱")]
    public String SchoolName { get; set; }
    [Display(Name = "學(xué)校類(lèi)型")]
    public SchoolTypeEnum? SchoolType { get; set; }
}
    

然后修改SchoolListVM，將它的定義和SchoolSearcher關(guān)聯(lián) public class SchoolListVM : BasePagedListVM<School, SchoolSearcher>

最后修改GetSearchQuery，使用Searcher的數(shù)據(jù)

public override IOrderedQueryable<School> GetSearchQuery()
{
    var query = DC.Set<School>()
        .CheckContain(Searcher.SchoolCode, x=>x.SchoolCode)
        .CheckContain(Searcher.SchoolName, x=>x.SchoolName)
        .CheckEqual(Searcher.SchoolType, x=>x.SchoolType)
        .OrderBy(x => x.ID);
    return query;
}
    

CheckContain，CheckEqual等是框架提供的便捷函數(shù)，用來(lái)替換where語(yǔ)句，并優(yōu)化生成的查詢語(yǔ)句

實(shí)際情況中，我們并不總是輸出數(shù)據(jù)庫(kù)中的原始數(shù)據(jù)，很多時(shí)候我們需要對(duì)原有數(shù)據(jù)進(jìn)行加工，轉(zhuǎn)換，或者顯示數(shù)據(jù)庫(kù)中并不存在的新列

請(qǐng)看下面的例子

public class SchoolListVM : BasePagedListVM<School_View, SchoolSearcher>
{
    protected override List<GridAction> InitGridAction()
    {
        return new List<GridAction>
        {
            this.MakeStandardAction("School", GridActionStandardTypesEnum.Create, "新建","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.Edit, "修改","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.Delete, "刪除", "",dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.Details, "詳細(xì)","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.BatchEdit, "批量修改","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.BatchDelete, "批量刪除","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.Import, "導(dǎo)入","", dialogWidth: 800),
            this.MakeStandardExportAction(null,false,ExportEnum.Excel)
        };
    }
    protected override IEnumerable<IGridColumn<School_View>> InitGridHeader()
    {
        return new List<GridColumn<School_View>>{
            this.MakeGridHeader(x => x.SchoolCode),
            this.MakeGridHeader(x => x.SchoolName),
            this.MakeGridHeader(x => x.SchoolType),
            this.MakeGridHeader(x => x.Total).SetFormat(TotalFormat),
            this.MakeGridHeaderAction(width: 200)
        };
    }
    private string TotalFormat(School_View entity, object val)
    {
        return entity.SchoolCode + "," + entity.SchoolName + "," + entity.SchoolType;
    }
    public override IOrderedQueryable<School_View> GetSearchQuery()
    {
        var query = DC.Set<School>()
            .CheckContain(Searcher.SchoolCode, x=>x.SchoolCode)
            .CheckContain(Searcher.SchoolName, x=>x.SchoolName)
            .CheckEqual(Searcher.SchoolType, x=>x.SchoolType)
            .Select(x => new School_View
            {
                ID = x.ID,
                SchoolCode = x.SchoolCode,
                SchoolName = x.SchoolName,
                SchoolType = x.SchoolType
            })
            .OrderBy(x => x.ID);
        return query;
    }
}
public class School_View : School{
    public string Total {get;set;}
}
    

上面代碼中，我們新建了School_View類(lèi)，用于擴(kuò)展School來(lái)顯示模型中并不存在的字段

然后我們通過(guò)在列上調(diào)用SetFormat方法來(lái)指定一個(gè)函數(shù)用于返回這列需要顯示的數(shù)據(jù)

SetFormat接受的方法可以直接返回string，也可以返回List<ColumnFormatInfo>

ColumnFormatInfo的作用主要是方便我們生成一些按鈕顯示在列表中，如果返回string的話，比如我們需要根據(jù)某列數(shù)據(jù)生成一個(gè)按鈕，點(diǎn)擊按鈕后彈出指定url的窗口，可能需要開(kāi)發(fā)人員編寫(xiě)大量js

ColumnFormatInfo提供了很多擴(kuò)展函數(shù)方便開(kāi)發(fā)人員生成各種按鈕，比如MakeDialogButton，MakeScriptButton，MakeDownloadButton等

以下例子演示了一個(gè)SetFormat的函數(shù)，它根據(jù)用戶的照片ID，生成兩個(gè)按鈕，一個(gè)用來(lái)下載，一個(gè)用來(lái)彈出窗口直接顯示照片

private List<ColumnFormatInfo> PhotoIdFormat(FrameworkUser_View entity, object val)
{
    return new List<ColumnFormatInfo>
    {
        ColumnFormatInfo.MakeDownloadButton(ButtonTypesEnum.Button,entity.PhotoId),
        ColumnFormatInfo.MakeViewButton(ButtonTypesEnum.Button,entity.PhotoId,640,480),
    };
}
    

在項(xiàng)目中，我們還經(jīng)常遇到使用grid來(lái)批量編輯數(shù)據(jù)的情況，

請(qǐng)看下面的例子

public class StudentListVm : BasePagedListVM<Student,StudentSearcher>
    {
        public StudentListVm()
        {
            DetailGridPrix = "Students";
        }
        protected override List<GridAction> InitGridAction()
        {
            return new List<GridAction>
            {
                this.MakeStandardAction("Employee", GridActionStandardTypesEnum.AddRow, ""),
                this.MakeStandardAction("Employee", GridActionStandardTypesEnum.RemoveRow, ""),
            };
        }
        protected override IEnumerable<IGridColumn<Student>> InitGridHeader()
        {
            return new List<GridColumn<Student>>{
                this.MakeGridHeader(x => x.LoginName).SetEditType(EditTypeEnum.TextBox),
                this.MakeGridHeader(x => x.Name).SetEditType(EditTypeEnum.TextBox),
                this.MakeGridHeader(x => x.Sex).SetEditType(EditTypeEnum.ComboBox, typeof(Models.SexEnum).ToListItems(pleaseSelect:true)),
                this.MakeGridHeader(x => x.CellPhone).SetEditType(EditTypeEnum.TextBox),
                this.MakeGridHeader(x=>x.IsValid).SetEditType(EditTypeEnum.CheckBox)
            };
        }
        public override IOrderedQueryable<Student> GetSearchQuery()
        {
            List<Student> data = new List<Student>
            {
                new Student{ LoginName = "zhangsan", Name="張三", Sex= Models.SexEnum.Male, CellPhone="13012213483", ExcelIndex = 0, IsValid = true, ID = new Guid("6F5C2D15-4871-4083-B269-06F456A4F1B6")},
                new Student{ LoginName = "lisi", Name="李四", Sex= Models.SexEnum.Male, CellPhone="13075829654", ExcelIndex = 1, IsValid = false, ID = new Guid("9C7BC358-B8BD-4547-AFC1-11BF6F2B608B")},
                new Student{ LoginName = "wangwu", Name="王五", Sex= Models.SexEnum.Male, CellPhone="13098635100", ExcelIndex = 2, IsValid = true, ID = new Guid("3BF9217C-1ACF-4D80-9899-42CFDA4C8746")},
                new Student{ LoginName = "zhaoliu", Name="趙六", Sex= Models.SexEnum.Female, CellPhone="13035698123", ExcelIndex = 3, IsValid = false, ID = new Guid("0C7F6A24-A08D-46BD-86AC-6B6A391A9F04")},
            };
            var query = data.AsQueryable().Where(x=>
                    (string.IsNullOrEmpty(Searcher.LoginName) || x.LoginName.Contains(Searcher.LoginName)) &&
                    (string.IsNullOrEmpty(Searcher.Name) || x.Name.Contains(Searcher.Name)) &&
                    (Searcher.Sex == null || x.Sex == Searcher.Sex) 
                )
                .OrderBy(x => x.ExcelIndex);
            return query;
        }
    }
    

上面代碼中，我們首先指定了DetailGridPrix字段，這個(gè)字段是告訴框架提交之后應(yīng)該將數(shù)據(jù)保存在哪里，比如我們?cè)O(shè)定DetailGridPrix="Students"，那么提交的時(shí)候，框架會(huì)使用Students[0].Id,Students[0].Name,Students[1].Id,Students[1].Name這種形式來(lái)提交數(shù)據(jù)

然后在InitGridAction方法中，我們定義了兩個(gè)按鈕，分別是AddRow和RemoveRow類(lèi)型。這兩個(gè)按鈕負(fù)責(zé)動(dòng)態(tài)給Grid添加或者刪除行

最后再I(mǎi)nitGridHeader方法中，我們使用SetEditType方法給每一列定義需要使用的控件