datarow

问题 I need to add data to datatable and show it in a gridview. After entering each item, gridview should update automatically. DataTable obj_dt_grdvw = new DataTable(); DataRow obj_dt_row = obj_dt_grdvw.NewRow(); obj_dt_grdvw.Columns.Add("_Pur_Product_Id", typeof(string)); obj_dt_grdvw.Columns.Add("Product_pur_Name", typeof(string)); obj_dt_row["_Pur_Product_Id"] = _Pur_Product_Id; obj_dt_row["Product_pur_Name"] = Product_pur_Name; obj_dt_grdvw.Rows.Add(obj_dt_row); return obj_dt_grdvw; After

问题 default column get for a dataRow in .designer.cs is like public partial class Fi_securityRow : global::System.Data.DataRow { [global::system.diagnostics.debuggernonusercodeattribute()] [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Data.Design.TypedDataSetGenerator", "4.0.0.0")] public override System.DateTime Exp_dt { get { try { return ((global::System.DateTime)(this[this.tableFi_security.Exp_dtColumn])); } catch (global::System.InvalidCastException e) { throw new global:

问题 I have gridview1 on sample.asp page. It has about 15 rows. What i want to do is: If i click on a row (say row 7) in the gridview1, it should update a few other rows (say rows 2,3,4) in the same gridview . On clicking the row, I want to call the function UpdateOnClick() that is already present in the sample.asp.cs file. This function should change the values in the desired rows on the same gridview. I want to update a few other rows on the same gridview how can i achieve this? 回答1: You can

问题 C# Assigning a value to DataRow["haswhatnots"] = hasWhatnots is awful slow. hasWhatnots is a boolean value. I have profiled this line and with 560000 hits the execution time is 82 seconds. Of course the profiler has some effect on the performance, but still the performance of this is grazy slow! Any hints on the issue. The DataRow is part of a DataTable which is bound to BindingSource that is bound to DataGridView.Datasource. 回答1: (edit: only just saw that you are data-binding) The first

问题 Currently, I am using a SqlDataReader loaded up with a simple database 'Select' query. Each row represents a domain object, so I inflate each object like this: Dim loadedItems As New List(Of Item) Dim dr As SqlDataReader = GetItemsDataReader() While dr.Read() Dim item As Item = GetItemFromData(dr) loadedItems.Add(item) End While The GetItemFromData method I wrote looks something like this: Private Function GetItemFromData(dr As SqlDataReader) As Item Dim loadedItem As New Item() loadedItem.ID

问题 I have DataTable object with next data: Id Value 1 val1 3 val2 2 val3 I'm selecting one row next way: table.Select("Id=1"); This query gives me row 1 val1 And next I want to take the row next to selected one, i.e. row 3 val2 Can I do this somehow? Is it possible? Maybe there is something like row's position in a table, that I can use to select next row by incrementing this value? 回答1: DataTable.Rows.IndexOf() is the only thing that I can think of. How: var rows=table.Select("Id=1"); var

问题 I'm writing a small app to do a little processing on some cells in a CSV file I have. I've figured out how to read and write CSV files with a library I found online, but I'm having trouble: the library parses CSV files into a DataTable, but, when I try to change a cell of the table, it isn't saving the change in the table! Below is the code in question. I've separated the process into multiple variables and renamed some of the things to make it easier to debug for this question. Code Inside

问题 I use a extension method to check a DataRowField for null public static string GetValue(this System.Data.DataRow Row, string Column) { if (Row[Column] == DBNull.Value) { return null; } else { return Row[Column].ToString(); } } Now I wonder if i could make this more generic. In my case the return type is always string but the Column could also be Int32 or DateTime Something like public static T GetValue<T>(this System.Data.DataRow Row, string Column, type Type) 回答1: public static T value<T>

问题 I am trying to extract values from a datagrid, by iterating through all the rows of the datagrid foreach (DataRow drv in PGIPortfolio.Items) { // DataRow row = drv.Row; string acname = drv["Portfolio"].ToString(); string paramt = drv["Par Amount"].ToString(); MessageBox.Show(acname); } But it is giving me an InvalidCastException at DataRow drv. Could someone tell me what changes I should make so it works? The datagrid has a binding, and it is being populated by a stored procedure from ms sql

问题 I have a datatable with one column: this.callsTable.Columns.Add("Call", typeof(String)); I then want to add a row to that datatable, but want to give a specific index, the commented number is the desired index: this.callsTable.Rows.Add("Legs"); //11 Update: Must be able to handle inputting hundreds of rows with unique indexes. The index must be what is defined by me no matter if there are enough rows in the table or not for the insertat function. 回答1: You can use DataTable.Rows.InsertAt