|
Form activeForm = this.ActiveMdiChild as Form;
string title = activeForm.Text;
MessageBox.Show(title);
when i'm use this code the following is displayed "Object reference not set to an instance of an object." that point out the first line............please any one can help me.......
|
|
|
|
|
Sounds like you have a null value somewhere. Can you post the section of code that's giving you trouble?
|
|
|
|
|
If you step through this code in your debugger you will be able to see if there is a valid ActiveMdiChild to set into the variable.
Veni, vidi, abiit domum
|
|
|
|
|
based on what I see it must be that you activeForm has not be initialized and is null. Without more code can't be certain.
|
|
|
|
|
please help me,friend
i want enter key search in textbox then click on the button and display data in DataGridView
tank you friends
|
|
|
|
|
|
You forgot to ask how to save data in a database. I suggest you try the how to[^]'s and some tutorials; it won't be very fun to learn it by asking every task in a forum.
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
|
|
|
|
|
please help me,friend
i want enter key search in textbox then click on the button and display data in DataGridView
tank you friends
|
|
|
|
|
Try this link:
http://msdn.microsoft.com/en-us/library/aeez5k4f.aspx
|
|
|
|
|
hi friends
i want display data from table(sql server) in the dataGridView
tanke you
|
|
|
|
|
|
hi friends
How i can delete data from data base(sql server) in C#?????
|
|
|
|
|
this is simple script to delete using webform asp.net C#
here is my code:
1. adding connection in Web.config
Web.config
==========
<connectionStrings>
<add name="myConnection" providerName="System.Data.SqlClient" connectionString="server=.\SQLEXPRESS;Initial Catalog=MyDB;Integrated Security=True"/>
</connectionStrings>
2. in default.aspx
default.aspx
============
added namespace:
using System.Data.SqlClient;
using System.Configuration;
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
string connProvider = ConfigurationManager.ConnectionStrings["myConnection"].ToString();
using (SqlConnection cnn = new SqlConnection(connProvider))
{
cnn.Open();
string userid = "1";
string query = "Delete Users Where UserID = '" + userid + "'";
using (SqlCommand cmd = new SqlCommand(query, cnn))
{
cmd.ExecuteNonQuery();
}
}
}
}
hope this help. (Update)= this code not recommended for develop, you can try it for learn and you can improve your code.
regard,
Ade Ruyani
modified 24-Dec-13 3:49am.
|
|
|
|
|
Reason for my downvote: Do not concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Use Parametrized queries instead. Even in a simple example like this, it takes hardly any extra work to do it properly!
Never underestimate the power of stupid things in large numbers
--- Serious Sam
|
|
|
|
|
Thank you sam, this is just a simple code, whether they can improve they're code using store procedure or else.
|
|
|
|
|
Ade.Ruyani.Z wrote: this is just a simple code It is still a bad example, because it leads to careless coding.
Veni, vidi, abiit domum
|
|
|
|
|
int RowsAffected = 0;
using(SqlConnection cn = new SqlConnection(ConnectionStringHere))
{
cn.Open();
using(SqlCommand cmd = new SqlCommand())
{
cmd.Connection = cn;
cmd.CommandType = CommandType.Text;
cmd.CommandText = "Delete from tablename where id = @id";
cmd.Parameters.AddWithValue("@id",id);
RowsAffected = cmd.ExecuteNonQuery();
}
}
Every day, thousands of innocent plants are killed by vegetarians.
Help end the violence EAT BACON
|
|
|
|
|
|
hi friends
How i can delete data from data base(sql server) in C#?????
|
|
|
|
|
|
I am using Visual Studio 2010 with Sql server Express Edition 2005 as backend DB. I've a form with DataGridView with following columns:
OrderID
ProductID
UnitPrice
Quantity
Total
DataGridView is bind to Dataset Table, "Total" is a Calculated column which I've added using following code:
column = new DataColumn();
column.DataType = Type.GetType("System.Double");
column.ColumnName = "Total";
ds.Tables[0].Columns.Add(column);
ds.Tables[0].Columns["Total"].Expression = "UnitPrice * Quantity";
Code works fine, it calculate the Total by multiplying UnitPrice to Quantity. The problem is this calculation is made when I move to new row. What I need is to it calculate Total when there is any change in UnitPrice or Quantity.
Is it possible? Any ideas/Suggestions will be highly appreciated.
Regards
Ahmed
|
|
|
|
|
Have you tried to update the values in the CellLeave event for your datagrid.
|
|
|
|
|
No, can you give me some sample code please?
|
|
|
|
|
after looking a little more, it may be better to use the cellvaluechanged event...
sample
(note this was tested only in C# win32.forms, and the column ValueTypes are strings):
private void dataGrid_CellValueChanged(object sender, DataGridViewCellEventArgs e) {
if ((e.RowIndex >= 0) && e.ColumnIndex != DataGrid.Columns["Total"].Index) {
int r = e.RowIndex;
int Qty = 0;
int.TryParse((string)DataGrid["Quantity", r].Value, out Qty);
double Price = 0D;
double.TryParse((string)DataGrid["UnitPrice", r].Value, out Price);
DataGrid["Total", r].Value = Price * Qty;
}
}
modified 24-Dec-13 19:07pm.
|
|
|
|
|
This helps a lot....big thanks...
|
|
|
|