当我在Wpf应用程序中绑定数据表时，我正在获取空数据网格 [英] I Am Getting Null Data Grid, When I Bind With Datatable In Wpf Application
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问题描述
当我使用linq lambda表达式绑定wpf中的datagrid时，它会填充数据网格，但是当我尝试将此linq结果转换为datatable时，我的代码下面填充null datagrid，我尝试了....
var join = dm.Export_Matrilas_s
.Where（ rh = > rh.Material_type == 5 ）
.Join（dm.Parti_Infos， p = > p.Parti_Id，w = > w.Parti_Id，（p，w）= > new {p.Export_Matrilas_id，p.Material_type，p.Owncom，w .Organization，p。日期}）
.Join（dm.Own_Company_Infos，r = > r.Owncom，y = > y.Company_Id，（r，y）= > new { r，y.Organization_Name}）
.Join（dm.Material_Types，n = > nrMaterial_type，b = > b.Id，（n，t）= > new {nr Export_Matrilas_id，t.Meterial_Name，n.Organization_Name，nrOrganization，nrDate}）
.ToList（）;
DataTable gettbl = ToDataTable（ join ）;
mygride.DataContext = gettbl.DefaultView;
这里我使用方法转换为datatable
public DataTable ToDataTable< T>（IList< T>数据） // T是任何泛型类型
{
PropertyDescriptorCollection props = TypeDescriptor.GetProperties（ typeof （T））;
DataTable table = new DataTable（）;
for （ int i = 0 ; i < props.Count; i ++）
{
PropertyDescriptor prop = props [i];
// table.Columns.Add（prop.DisplayName，prop.PropertyType）;
table.Columns.Add（prop.DisplayName，Nullable.GetUnderlyingType（prop.PropertyType）?? prop.PropertyType）;
}
object [] values = new 对象 [props.Count];
DataRow行;
foreach （ var 记录 in data）
{
row = table.NewRow（）;
for （ int i = 0 ; i < table.Columns.Count; i ++）
{
values [i] = props [i] .GetValue（record） ）！= null ？道具[i] .GetValue（记录）：DBNull.Value;
}
table.Rows.Add（row）;
}
table.Rows.Add（values）;
return 表;
}
这是我的xaml代码：
< UserControl x：类 = Iqbal_Silks.Export_Tanee_Records
xmlns = http://schemas.microsoft.com/winfx/2006/xaml/presentation
< span class =code-attribute>
< span class =code-attribute> xmlns：x = http://schemas.microsoft。 com / winfx / 2006 / xaml
xmlns：mc = http://schemas.openxmlformats.org/markup-compatibility / 2006
< span class =code-attribute> xmlns：d = http://schemas.microsoft.com/expression/blend/2008
< span class =code-attribute> 高度 = 700 宽度 = 900 >
< UserControl.Resources >
< span class =code-keyword>< ResourceDictionary Source = ../ Themes / Dictionary1.xaml / >
< < span class =code-leadattribute> / UserControl.Resources >
< 网格 >
< DataGrid x：名称 = mygride 保证金 = 3,243,10,64 AutoGenerateColumns = False AlternatingRowremoved = AliceBlue VerticalContentAlignment = 中心 CanUserResizeRows = False HorizontalContentAlignment = 中心 ScrollViewer.PanningMode = VerticalFirst IsReadOnly = True >
< DataGrid.Columns >
< DataGridTextColumn 标题 = 导出ID 宽度 = 自动 绑定 = {Binding Export_Matrilas_id} / >
< DataGridTextColumn 标题 = 材料 宽度 = 自动 绑定 = {Binding Meterial_Name} / >
< DataGridTextColumn 标题 = 公司 宽度 = 自动 < span class =code-attribute> Binding = {Binding Organization_Name} < span class =code-keyword> / > ;
< DataGridTextColumn 标题 = 客户端 宽度 = 自动 绑定 = {Binding Organization} / >
< DataGridTextColumn 标题 = 日期 宽度 = 自动 绑定 = {Binding Date} / >
< / DataGrid.Columns >
< / DataGrid >
< 按钮 < span class =code-attribute>内容 = Excel记录 x：名称 = btnviewchallan_Copy 样式 = {StaticResource Hdrclose} HorizontalAlignment = 左 保证金 = 616,641,0,0 VerticalAlignment = Top 宽度 = 94 高度 = 27 单击 = BtnviewchallanCopyClick / >
< StackPanel 方向 = 水平 HorizontalAlignment = 拉伸 保证金 = 10,644,768,32 >
< 按钮 名称 = btnFirstPage 内容 = << 点击 = btnFirstPage_Click / >
< 按钮 名称 = btnPreviousPage Conte nt = < 点击 = btnPreviousPage_Click < span class =code-keyword> / >
< 标签 名称 = lblPageIndex 内容 = {Binding ElementName = root，
Path = PageIndex，UpdateSourceTrigger = PropertyChanged} 宽度 = < span class =code-keyword> Auto / >
< < span class =code-leadattribute>标签 内容 = / >
< 标签 名称 = lblPageNumber 内容 = {Binding ElementName = root，
Path = NumberOfPages，UpdateSourceTrigger = PropertyChanged} 宽度 = 自动 / >
< 按钮 名称 = btnNextPage 内容 = < span class =code-keyword>> 点击 = btnNextPage_Click / >
< 按钮 名称 = btnLastPage 内容 = >> 点击 = btnLastPage_Click / >
< / StackPanel >
< / Grid >
解决方案
< blockquote>
我认为你的 ToDataTable 方法在 foreach 循环中有一个错误。试试这个版本。
public DataTable ToDataTable< t>（IList< t>数据） // T是任何泛型类型
{
PropertyDescriptorCollection props = TypeDescriptor。 GetProperties（ typeof （T））;
DataTable table = new DataTable（）;
for （ int i = 0 ; i < props.Count; i ++）
{
PropertyDescriptor prop = props [i];
// table.Columns.Add（prop.DisplayName，prop.PropertyType）;
table.Columns.Add（prop.DisplayName，Nullable.GetUnderlyingType（prop.PropertyType）?? prop.PropertyType）;
}
object [] values = new 对象 [props.Count];
foreach （ var 记录 in data）
{
for （ int i = 0 ; i < table.Columns.Count; i ++）
{
values [i] =道具[i] .GetValue（记录）！= null ？道具[i] .GetValue（记录）：DBNull.Value;
}
table.Rows.Add（values）;
}
return 表;
}
When I bind datagrid in wpf with of linq lambda expression its fill datagrid but when I try to convert this linq result in datatable then its fill null datagrid below my code which I tried ....
var join = dm.Export_Matrilas_s
.Where(rh => rh.Material_type == 5)
.Join(dm.Parti_Infos, p => p.Parti_Id, w => w.Parti_Id, (p, w) => new { p.Export_Matrilas_id, p.Material_type, p.Owncom, w.Organization, p.Date })
.Join(dm.Own_Company_Infos, r => r.Owncom, y => y.Company_Id, (r, y) => new { r, y.Organization_Name })
.Join(dm.Material_Types, n => n.r.Material_type, b => b.Id, (n, t) => new { n.r.Export_Matrilas_id, t.Meterial_Name, n.Organization_Name, n.r.Organization, n.r.Date })
.ToList();
DataTable gettbl = ToDataTable(join);
mygride.DataContext = gettbl.DefaultView;
Here I convert into datatable using method
public DataTable ToDataTable<T>(IList<T> data)// T is any generic type
{
PropertyDescriptorCollection props = TypeDescriptor.GetProperties(typeof(T));
DataTable table = new DataTable();
for (int i = 0; i < props.Count; i++)
{
PropertyDescriptor prop = props[i];
// table.Columns.Add(prop.DisplayName,prop.PropertyType);
table.Columns.Add(prop.DisplayName, Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType);
}
object[] values = new object[props.Count];
DataRow row;
foreach (var record in data)
{
row = table.NewRow();
for (int i = 0; i < table.Columns.Count; i++)
{
values[i] = props[i].GetValue(record) != null ? props[i].GetValue(record) : DBNull.Value;
}
table.Rows.Add(row);
}
table.Rows.Add(values);
return table;
}
Here is my xaml code:
<UserControl x:Class="Iqbal_Silks.Export_Tanee_Records"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
Height="700" Width="900">
<UserControl.Resources>
<ResourceDictionary Source="../Themes/Dictionary1.xaml"/>
</UserControl.Resources>
<Grid >
<DataGrid x:Name="mygride" Margin="3,243,10,64" AutoGenerateColumns="False" AlternatingRowremoved="AliceBlue" VerticalContentAlignment="Center" CanUserResizeRows="False" HorizontalContentAlignment="Center" ScrollViewer.PanningMode="VerticalFirst" IsReadOnly="True">
<DataGrid.Columns>
<DataGridTextColumn Header="Export ID" Width="Auto" Binding="{Binding Export_Matrilas_id}"/>
<DataGridTextColumn Header="Materials " Width="Auto" Binding="{Binding Meterial_Name}" />
<DataGridTextColumn Header="Company" Width="Auto" Binding="{Binding Organization_Name}"/>
<DataGridTextColumn Header="Client" Width="Auto" Binding="{Binding Organization}"/>
<DataGridTextColumn Header="Date" Width="Auto" Binding="{Binding Date}"/>
</DataGrid.Columns>
</DataGrid>
<Button Content="Excel Records" x:Name="btnviewchallan_Copy" Style="{StaticResource Hdrclose}" HorizontalAlignment="Left" Margin="616,641,0,0" VerticalAlignment="Top" Width="94" Height="27" Click="BtnviewchallanCopyClick" />
<StackPanel Orientation="Horizontal" HorizontalAlignment="Stretch" Margin="10,644,768,32">
<Button Name="btnFirstPage" Content="<<" Click="btnFirstPage_Click"/>
<Button Name="btnPreviousPage" Content="<" Click="btnPreviousPage_Click"/>
<Label Name="lblPageIndex" Content="{Binding ElementName=root,
Path=PageIndex, UpdateSourceTrigger=PropertyChanged}" Width="Auto"/>
<Label Content="of"/>
<Label Name="lblPageNumber" Content="{Binding ElementName=root,
Path=NumberOfPages, UpdateSourceTrigger=PropertyChanged}" Width="Auto"/>
<Button Name="btnNextPage" Content=">" Click="btnNextPage_Click"/>
<Button Name="btnLastPage" Content=">>" Click="btnLastPage_Click"/>
</StackPanel>
</Grid> 解决方案
I think your
ToDataTablemethod has a bug in theforeachloop. Try this version.public DataTable ToDataTable<t>(IList<t> data)// T is any generic type { PropertyDescriptorCollection props = TypeDescriptor.GetProperties(typeof(T)); DataTable table = new DataTable(); for (int i = 0; i < props.Count; i++) { PropertyDescriptor prop = props[i]; // table.Columns.Add(prop.DisplayName,prop.PropertyType); table.Columns.Add(prop.DisplayName, Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType); } object[] values = new object[props.Count]; foreach (var record in data) { for (int i = 0; i < table.Columns.Count; i++) { values[i] = props[i].GetValue(record) != null ? props[i].GetValue(record) : DBNull.Value; } table.Rows.Add(values); } return table; }
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