[英]C# WPF MVVM - Merge multiple csv to datagrid
我一直在研究这个小程序,它需要获取CSV文件的文件输入,将它们存储在列表框中,然后自动更新datagrid。 当添加更多文件时,datagrid需要使用新文件数据进行扩展并在其旁边添加。
在DataGridViewModel中,我的csv合并代码为:
public class DataGridViewModel
{
static public DataGridModel _dataGridModel = new DataGridModel();
public static void ReturnDataTableForGridView()
{
DataTable mainTable = new DataTable();
//-- #3 Test merge
foreach (var item in SidePanelViewModel.GetPathFileList())
{
DataTable dataTable = new DataTable();
try
{
string[] Lines = File.ReadAllLines(item.Filepath);
string[] Fields;
Fields = Lines[0].Split(new char[] { ';' });
int Cols = Fields.GetLength(0);
//1st row skal være kolonne navn;
for (int X = 0; X < Cols; X++)
dataTable.Columns.Add(Fields[X].ToLower(), typeof(string));
DataRow Row;
for (int T = 1; T < Lines.GetLength(0); T++)
{
Fields = Lines[T].Split(new char[] { ';' });
Row = dataTable.NewRow();
for (int f = 0; f < Cols; f++)
Row[f] = Fields[f];
dataTable.Rows.Add(Row);
}
//-- Merges every files(tables) into one.
mainTable.Merge(dataTable);
}
catch (Exception)
{
return null;
}
}
//-- Sets the datatablemerger which raises the propertychanged
_dataGridModel.DatatableMerger = mainTable;
}
}
DataGridModel类
public class DataGridModel : INotifyPropertyChanged
{
DataTable _dataTableMerger { get; set; } = new DataTable();
public DataTable DatatableMerger
{
get
{
return _dataTableMerger;
}
set
{
_dataTableMerger = value;
OnPropertychanged("DatatableMerger");
}
}
public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertychanged([CallerMemberName] string caller = "")
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(caller));
}
}
dataGridview类
public DataGridView()
{
InitializeComponent();
}
XAML代码:
<DataGrid x:Name="MainDataGrid" Grid.Row="1" VerticalAlignment="Stretch" Height="auto" ItemsSource="{Binding Path=DatatableMerger, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, NotifyOnSourceUpdated=True}" >
</DataGrid>
</Grid>
<UserControl.DataContext>
<Model:DataGridModel/>
</UserControl.DataContext>
当前输出:
希望的输出:
我的朋友以一个例子帮助了我。
跟随ansvar:
XAML中的DataContext错误。 您的视图必须与ViewModel而不是Model保持一致。
如果运行MVVM,则在后面的“视图”代码中使用按钮单击事件是错误的。 它必须在ViewModel中完成。
除此之外,您的CSV解析器是错误的工具。 一旦字段包含分号,换行符,或者如果将komma用作字段分隔符而不是分号,则它将中断。
阅读更多有关等的内容。有关CSV文件的RFC规范,请在这里使用或使用可以正确解析文件的库。 例如 ExcelDataReader ANd,如果您希望将其放入数据表; ExcelDataReader.DataSet
关于功能和正确绑定的示例,请参见以下说明:
MainWindow.cs
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
}
XAML
<Window.DataContext>
<local:DataGridViewModel/>
</Window.DataContext>
<Grid>
<DataGrid Margin="0,0,0,35" ItemsSource="{Binding DatatableMerger}"/>
<Button Content="Add rows" Margin="0,0,10,10" Command="{Binding AddRowsButtonClickCommand}" Height="20" VerticalAlignment="Bottom" HorizontalAlignment="Right" Width="75"/>
</Grid>
DataGridModel.cs
public class DataGridModel
{
public DataTable DatatableMerger { get; set; }
}
DataGridViewModel.cs
public class DataGridViewModel : INotifyPropertyChanged
{
private readonly DataGridModel _dataGridModel = new DataGridModel();
public DataTable DatatableMerger => _dataGridModel.DatatableMerger;
public ICommand AddRowsButtonClickCommand => new DelegateCommand(o => ReturnDataTableForGridView());
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyName) => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
public void ReturnDataTableForGridView()
{
var dt = new DataTable();
dt.Columns.Add("Foo");
dt.Columns.Add("Bar");
dt.Columns.Add("Baz");
for (var i = 0; i < 5; i++)
dt.Rows.Add($"Value {i}", i, DateTime.Now.AddSeconds(i));
_dataGridModel.DatatableMerger = dt;
OnPropertyChanged(nameof(DatatableMerger));
}
}
委托命令
public class DelegateCommand : ICommand
{
private readonly Predicate<object> _canExecute;
private readonly Action<object> _execute;
public event EventHandler CanExecuteChanged;
public DelegateCommand(Action<object> execute) : this(execute, null) { }
public DelegateCommand(Action<object> execute, Predicate<object> canExecute)
{
_execute = execute;
_canExecute = canExecute;
}
public bool CanExecute(object parameter)
{
if (_canExecute is null)
return true;
return _canExecute(parameter);
}
public void Execute(object parameter)
{
_execute(parameter);
}
public void RaiseCanExecuteChanged()
{
CanExecuteChanged?.Invoke(this, EventArgs.Empty);
}
}
并为合并功能。 使用YourMainTableName = Mergetables(Table1,table2)调用函数;
public DataTable MergeTables(DataTable Table1, DataTable Table2)
{
DataTable Mergetable = new DataTable();
foreach (DataColumn d in Table1.Columns)
{
Mergetable.Columns.Add(d.ColumnName);
}
foreach (DataColumn d in Table2.Columns)
{
Mergetable.Columns.Add(d.ColumnName);
}
int Table1Cols = Table1.Columns.Count;
int Table1Rows = Table1.Rows.Count;
int Table2Cols = Table2.Columns.Count;
int Table2Rows = Table2.Rows.Count;
DataRow row2;
bool end = false;
int RowCount = 0;
while (!end)
{
end = true;
if (RowCount < Table1Rows || RowCount < Table2Rows)
{
end = false;
row2 = Mergetable.NewRow();
if (RowCount < Table1Rows)
{
for (int col = 0; col < Table1Cols; col++)
{
row2[col] = Table1.Rows[RowCount][col];
}
}
if (RowCount < Table2Rows)
{
for (int col = 0; col < Table2Cols; col++)
{
row2[col + Table1Cols] = Table2.Rows[RowCount][col];
}
}
Mergetable.Rows.Add(row2);
}
RowCount++;
}
return Mergetable;
}
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