列表及导入导出

建立BasePagedListVM主要有以下几部

1. 定义继承自BasePagedListVM的类，将关联的Model作为泛型变量

2. 重写GetSearchQuery函数，将查询语句和逻辑写在这个函数里

3. 重写InitGridHeader函数，这个函数定义列表显示的列

4. 重写InitGridAction函数，这个函数定义列表中需要出现的操作按钮

下面以学校模型为例，展示如何编写一个简单的ListVM，学校模型的定义可以参考第一个模块

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, "删除", "",dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.Details, "详细","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.BatchEdit, "批量修改","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.BatchDelete, "批量删除","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.Import, "导入","", 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;
    }
}
    

上面代码建立了一个简单的ListVM，它没有任何搜索条件，默认每页20行查询所有School的数据，并使用输出列表同样的逻辑来完成导出Excel。同时它定义了新建，修改等按钮

RecordsPerPage属性可以设置每页行数，默认是20行，NeedPage属性可以设定是否要进行分页

MakeStandardExportAction的作用是在列表上生成一个导出按钮

MakeGridHeaderAction的作用是在列表上增加一个操作列，操作列中出现的按钮是在InitGridAction中定义的所有ShowInRow为true的动作。当使用MakeStandardAction创建默认动作时，修改，删除和详细都是每行显示的

在Controller中使用BasePagedListVM的步骤也是一目了然，请看下面的例子

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

必须使用CreateVM函数来创建ViewModel，而不要直接new。CreateVM函数会将当前Controller的Session，ModelState等信息传递给VM，并进行一些框架内部的操作

上面的例子并没有任何搜索条件，真实场景中这种情况是很少的，要在列表中加入搜索条件，有两个步骤

1. 定义一个继承自BaseSearcher的类，将搜索条件作为类的属性，并把ListVM类的第二个泛型变量设定为这个Searcher

2. 在GetSearchQuery函数中使用Searcher的数据来编写查询语句

比如建立一个下面的Searcher用于搜索学校数据

public class SchoolSearcher : BaseSearcher
{
    [Display(Name = "学校编码")]
    public String SchoolCode { get; set; }
    [Display(Name = "学校名称")]
    public String SchoolName { get; set; }
    [Display(Name = "学校类型")]
    public SchoolTypeEnum? SchoolType { get; set; }
}
    

然后修改SchoolListVM，将它的定义和SchoolSearcher关联 public class SchoolListVM : BasePagedListVM<School, SchoolSearcher>

最后修改GetSearchQuery，使用Searcher的数据

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数，用来替换where语句，并优化生成的查询语句

实际情况中，我们并不总是输出数据库中的原始数据，很多时候我们需要对原有数据进行加工，转换，或者显示数据库中并不存在的新列

请看下面的例子

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, "删除", "",dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.Details, "详细","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.BatchEdit, "批量修改","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.BatchDelete, "批量删除","", dialogWidth: 800),
            this.MakeStandardAction("School", GridActionStandardTypesEnum.Import, "导入","", 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;}
}
    

上面代码中，我们新建了School_View类，用于扩展School来显示模型中并不存在的字段

然后我们通过在列上调用SetFormat方法来指定一个函数用于返回这列需要显示的数据

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们生成一些按钮显示在列表中，如果返回string的话，比如我们需要根据某列数据生成一个按钮，点击按钮后弹出指定url的窗口，可能需要开发人员编写大量js

ColumnFormatInfo提供了很多扩展函数方便开发人员生成各种按钮，比如MakeDialogButton，MakeScriptButton，MakeDownloadButton等

以下例子演示了一个SetFormat的函数，它根据用户的照片ID，生成两个按钮，一个用来下载，一个用来弹出窗口直接显示照片

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),
    };
}
    

在项目中，我们还经常遇到使用grid来批量编辑数据的情况，

请看下面的例子

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="张三", 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="赵六", 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;
        }
    }
    

上面代码中，我们首先指定了DetailGridPrix字段，这个字段是告诉框架提交之后应该将数据保存在哪里，比如我们设定DetailGridPrix="Students"，那么提交的时候，框架会使用Students[0].Id,Students[0].Name,Students[1].Id,Students[1].Name这种形式来提交数据

然后在InitGridAction方法中，我们定义了两个按钮，分别是AddRow和RemoveRow类型。这两个按钮负责动态给Grid添加或者删除行

最后再InitGridHeader方法中，我们使用SetEditType方法给每一列定义需要使用的控件