用动态列填充Datagrid [英] Filling a Datagrid with dynamic Columns
问题描述
我有一个Datagrid需要动态填充。
表格如下:
id |图像|名称|说明| Name-1 |名称N
前4列是静态的,其他列是动态的。用户应该可以添加任意数量的用户。
我尝试通过在表中将它们相互放在一起来比较多个用户的数据。
现在我有一个列表框,它包含动态生成列的名称和填充静态列的方法。我也可以加载每个用户的数据。现在我需要将它们合并到一个大表中。
主要问题现在是:如何将Userdata和静态内容放在一个datagrid中。 >
至少有三种方法:
- 从代码隐藏手动修改DataGrid的列
- 使用DataTable作为ItemsSource *
-
使用CustomTypeDescriptor
*推荐简单
第一种方法:使用代码隐藏在运行时生成DataGrid的列。这实现起来很简单,但也可能感觉有点黑客,特别是如果你使用MVVM。所以你可以使用固定列的DataGrid:
< DataGrid x:Name =grid>
< DataGrid.Columns>
< DataGridTextColumn Binding ={Binding id}Header =id/>
< DataGridTextColumn Binding ={Binding image}Header =image/>
< /DataGrid.Columns>
< / DataGrid>
当您的名称准备就绪时,通过添加/删除列来修改网格,例如:
//向数据网格添加新列
void AddColumns(string [] newColumnNames)
{
foreach(newColumnNames中的字符串名称)
{
grid.Columns.Add(new DataGridTextColumn {
//绑定到一个字典属性
Binding = new Binding(自定义[+名称+]),
标题=名称
});
}
}
你将要创建一个包装类,应该包含原始类,加上一个字典来包含自定义属性。假设你的主排类是User,那么你会想要一个这样的包装类:
public class CustomUser :user
{
public Dictionary< string,object>自定义{get;组;
public CustomUser():base()
{
Custom = new Dictionary< string,object>();
}
}
填充 ItemsSource
这个新的CustomUser类的集合:
void PopulateRows(User [] users,Dictionary< string,object> [] customProps)
{
var customUsers = users.Select((user,index)=> new CustomUser {
Custom = customProps [index];
});
grid.ItemsSource = customUsers;
}
所以把它绑在一起,例如:
var newColumnNames = new string [] {Name1,Name2};
var users = new User [] {new User {id =First User}};
var newProps = new Dictionary< string,object> [] {
new Dictionary< string,object> {
Name1,First User of First User,
Name2,Second Name of First User,
},
};
AddColumns(newColumnNames);
PopulateRows(users,newProps);
第二种方式:使用 DataTable 。这使得使用定制类型的基础设施,但更容易使用。只需将DataGrid的 ItemsSource
绑定到一个 DataTable.DefaultView
属性:
< DataGrid ItemsSource ={Binding Data.DefaultView}AutoGenerateColumns =True/>
然后,您可以自定义列,例如:
Data = new DataTable();
//创建固定列
Data.Columns.Add(id);
Data.Columns.Add(image);
//创建自定义列
Data.Columns.Add(Name1);
Data.Columns.Add(Name2);
//添加一行作为对象数组
Data.Rows.Add(new object [] {123,image.png,Foo,Bar});
第三种方法:利用.Net类型系统的可扩展性。具体来说,使用 CustomTypeDescriptor
。这允许您在运行时创建自定义类型;这又使您能够告诉DataGrid您的类型具有属性Name1,Name2,...NameN或任何其他您想要的。有关此方法的简单示例,请参阅此处。
I have an Datagrid which needs to get filled dynamicly.
The tablelayout is like:
id | image | name | Description | Name-1 | Name-N
The first 4 columns are static the others are dynamic. The User should be able to add as many users as he wants.
I try to compare data of multiple users by putting them next to each other in the table.
Right now I have an Listbox whitch containes the Names of the dynamic generated Columns and an method that filles the static columns. I also can load the datas for each User. now I need to merge them to one big Table.
The main Problem is now: How to put the "Userdata" and the static content in one datagrid.
There are at least three ways of doing this:
- Modify the DataGrid's columns manually from code-behind
- Use a DataTable as the ItemsSource *
Use a CustomTypeDescriptor
*recommended for simplicity
1st approach: use code-behind to generate the DataGrid's columns at runtime. This is simple to implement, but maybe feels a bit hackish, especially if you're using MVVM. So you'd have your DataGrid with fixed columns:
<DataGrid x:Name="grid">
<DataGrid.Columns>
<DataGridTextColumn Binding="{Binding id}" Header="id" />
<DataGridTextColumn Binding="{Binding image}" Header="image" />
</DataGrid.Columns>
</DataGrid>
When you have your "Names" ready, then modify the grid by adding/removing columns, eg:
// add new columns to the data grid
void AddColumns(string[] newColumnNames)
{
foreach (string name in newColumnNames)
{
grid.Columns.Add(new DataGridTextColumn {
// bind to a dictionary property
Binding = new Binding("Custom[" + name + "]"),
Header = name
});
}
}
You'll want to create a wrapper class, which should contain the original class, plus a dictionary to contain the custom properties. Let's say your main row class is "User", then you'd want a wrapper class something like this:
public class CustomUser : User
{
public Dictionary<string, object> Custom { get; set; }
public CustomUser() : base()
{
Custom = new Dictionary<string, object>();
}
}
Populate the ItemsSource
with a collection of this new "CustomUser" class:
void PopulateRows(User[] users, Dictionary<string, object>[] customProps)
{
var customUsers = users.Select((user, index) => new CustomUser {
Custom = customProps[index];
});
grid.ItemsSource = customUsers;
}
So tying it together, for example:
var newColumnNames = new string[] { "Name1", "Name2" };
var users = new User[] { new User { id="First User" } };
var newProps = new Dictionary<string, object>[] {
new Dictionary<string, object> {
"Name1", "First Name of First User",
"Name2", "Second Name of First User",
},
};
AddColumns(newColumnNames);
PopulateRows(users, newProps);
2nd approach: use a DataTable. This makes use of the custom-type infrastructure under the hood, but is easier to use. Just bind the DataGrid's ItemsSource
to a DataTable.DefaultView
property:
<DataGrid ItemsSource="{Binding Data.DefaultView}" AutoGenerateColumns="True" />
Then you can define the columns however you like, eg:
Data = new DataTable();
// create "fixed" columns
Data.Columns.Add("id");
Data.Columns.Add("image");
// create custom columns
Data.Columns.Add("Name1");
Data.Columns.Add("Name2");
// add one row as an object array
Data.Rows.Add(new object[] { 123, "image.png", "Foo", "Bar" });
3rd approach: make use of the extensibility of .Net's type system. Specifically, use a CustomTypeDescriptor
. This allows you to create a custom type at runtime; which in turn enables you to tell the DataGrid that your type has the properties "Name1", "Name2", ... "NameN", or whatever others you want. See here for a simple example of this approach.
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