可见列

TreeList允许您以编程方式隐藏它的一些列。

在本文中:

• 基础知识
• 笔记
• 例子
  • 在按钮单击上切换列的可见性
  • 带有模板的隐藏树列表列
  • 隐藏一个基于条件的树列表列

基础知识

要隐藏TreeList列，请设置其可见参数假．要根据特定条件隐藏列，您可以传递，例如，三元运算符或返回的方法保龄球-应用程序可以根据其逻辑(如屏幕大小)提供表达式。

@*通过设置Visible参数为false隐藏Id TreeList列*@         @code {public List Data {get;设置;}公共类雇员{公共列表<雇员> DirectReports {get;设置;}公共int Id{获取;设置;}公共字符串名称{获取;设置;}公共字符串EmailAddress{获取; set; } public DateTime HireDate { get; set; } } public int LastId { get; set; } = 1; protected override async Task OnInitializedAsync() { Data = await GetTreeListData(); } async Task> GetTreeListData() { List data = new List(); for (int i = 1; i < 15; i++) { Employee root = new Employee { Id = LastId, Name = $"root: {i}", EmailAddress = $"{i}@example.com", HireDate = DateTime.Now.AddYears(-i), DirectReports = new List() }; data.Add(root); LastId++; for (int j = 1; j < 4; j++) { int currId = LastId; Employee firstLevelChild = new Employee { Id = currId, Name = $"first level child {j} of {i}", EmailAddress = $"{currId}@example.com", HireDate = DateTime.Now.AddDays(-currId), DirectReports = new List(), }; root.DirectReports.Add(firstLevelChild); LastId++; for (int k = 1; k < 3; k++) { int nestedId = LastId; // populate the parent's collection firstLevelChild.DirectReports.Add(new Employee { Id = LastId, Name = $"second level child {k} of {j} and {i}", EmailAddress = $"{nestedId}@example.com", HireDate = DateTime.Now.AddMinutes(-nestedId) }); ; LastId++; } } } return await Task.FromResult(data); } }

笔记

不可见的列(可见= " false ")会有以下行为:

• 不会是可编辑的．
• 模板不会被渲染。
  • 当使用行模板列的可见性应该由行模板本身的应用程序实现——树列表只能切换标题的可见性。

例子

在本节中，你会看到以下例子:

• 在按钮单击上切换列的可见性
• 带有模板的隐藏树列表列
• 隐藏一个基于条件的树列表列

在按钮单击上切换列的可见性

的值可见参数，这将切换列。

切换一个列的可见性将保持其在树列表中的原始顺序。*@ 
 切换Id列的可见性 
         @code {public bool isVisible {get;设置;} = true;public List Data {get;设置;}公共类雇员{公共列表<雇员> DirectReports {get;设置; } public int Id { get; set; } public string Name { get; set; } public string EmailAddress { get; set; } public DateTime HireDate { get; set; } } public int LastId { get; set; } = 1; protected override async Task OnInitializedAsync() { Data = await GetTreeListData(); } async Task> GetTreeListData() { List data = new List(); for (int i = 1; i < 15; i++) { Employee root = new Employee { Id = LastId, Name = $"root: {i}", EmailAddress = $"{i}@example.com", HireDate = DateTime.Now.AddYears(-i), DirectReports = new List() }; data.Add(root); LastId++; for (int j = 1; j < 4; j++) { int currId = LastId; Employee firstLevelChild = new Employee { Id = currId, Name = $"first level child {j} of {i}", EmailAddress = $"{currId}@example.com", HireDate = DateTime.Now.AddDays(-currId), DirectReports = new List(), }; root.DirectReports.Add(firstLevelChild); LastId++; for (int k = 1; k < 3; k++) { int nestedId = LastId; // populate the parent's collection firstLevelChild.DirectReports.Add(new Employee { Id = LastId, Name = $"second level child {k} of {j} and {i}", EmailAddress = $"{nestedId}@example.com", HireDate = DateTime.Now.AddMinutes(-nestedId) }); ; LastId++; } } } return await Task.FromResult(data); } }

带有模板的隐藏树列表列

当使用特定于单元格的模板时，它们根本不会被呈现。但是，如果您正在使用RowTemplate，请确保在那里也处理列的可见性。

@* Name列的模板将不会被渲染*@           @code {public List Data {get;设置;}公共类雇员{公共列表<雇员> DirectReports {get;设置;}公共int Id{获取;设置;}公共字符串名称{获取; set; } public string EmailAddress { get; set; } public DateTime HireDate { get; set; } } public int LastId { get; set; } = 1; protected override async Task OnInitializedAsync() { Data = await GetTreeListData(); } async Task> GetTreeListData() { List data = new List(); for (int i = 1; i < 15; i++) { Employee root = new Employee { Id = LastId, Name = $"root: {i}", EmailAddress = $"{i}@example.com", HireDate = DateTime.Now.AddYears(-i), DirectReports = new List() }; data.Add(root); LastId++; for (int j = 1; j < 4; j++) { int currId = LastId; Employee firstLevelChild = new Employee { Id = currId, Name = $"first level child {j} of {i}", EmailAddress = $"{currId}@example.com", HireDate = DateTime.Now.AddDays(-currId), DirectReports = new List(), }; root.DirectReports.Add(firstLevelChild); LastId++; for (int k = 1; k < 3; k++) { int nestedId = LastId; // populate the parent's collection firstLevelChild.DirectReports.Add(new Employee { Id = LastId, Name = $"second level child {k} of {j} and {i}", EmailAddress = $"{nestedId}@example.com", HireDate = DateTime.Now.AddMinutes(-nestedId) }); ; LastId++; } } } return await Task.FromResult(data); } }

隐藏一个基于条件的树列表列

这个例子展示了根据数据中的简单条件隐藏列。您可以将其更改为使用其他视图模型数据—例如屏幕尺寸、存储的用户首选项或任何其他逻辑。

@* Id列被隐藏，因为TreeList的数据包含1 *@        @code {public List Data {get;设置;}公共类雇员{公共列表<雇员> DirectReports {get;设置;}公共int Id{获取;设置;}公共字符串名称{获取; set; } public string EmailAddress { get; set; } public DateTime HireDate { get; set; } } public int LastId { get; set; } = 1; protected override async Task OnInitializedAsync() { Data = await GetTreeListData(); } async Task> GetTreeListData() { List data = new List(); for (int i = 1; i < 15; i++) { Employee root = new Employee { Id = LastId, Name = $"root: {i}", EmailAddress = $"{i}@example.com", HireDate = DateTime.Now.AddYears(-i), DirectReports = new List() }; data.Add(root); LastId++; for (int j = 1; j < 4; j++) { int currId = LastId; Employee firstLevelChild = new Employee { Id = currId, Name = $"first level child {j} of {i}", EmailAddress = $"{currId}@example.com", HireDate = DateTime.Now.AddDays(-currId), DirectReports = new List(), }; root.DirectReports.Add(firstLevelChild); LastId++; for (int k = 1; k < 3; k++) { int nestedId = LastId; // populate the parent's collection firstLevelChild.DirectReports.Add(new Employee { Id = LastId, Name = $"second level child {k} of {j} and {i}", EmailAddress = $"{nestedId}@example.com", HireDate = DateTime.Now.AddMinutes(-nestedId) }); ; LastId++; } } } return await Task.FromResult(data); } }

另请参阅

• 现场演示:TreeList列