ASP.NET GridView how to cancel update - asp.net

I have GridView with connected SqlDataSource and I want cancel updating row when my condition is false in OnRowUpdating event? How to do it? Thank you.

try
protected void Page_Load(object sender, EventArgs e)
{
GridView1.RowUpdating += new GridViewUpdateEventHandler(GridView1_RowUpdating);
}
void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
e.Cancel = true;
}

Related

asp.net: Create Handles clause for control class

Is there a way that I force all TextBoxes (as an example) .. on an asp.net form, to go through the same routine, during a "postback" event or onchange event?
Here is example code.
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
textBox1.TextChanged += new EventHandler(textBox_TextChanged);
textBox2.TextChanged += new EventHandler(textBox_TextChanged);
}
}
protected void textBox_TextChanged(object sender, EventArgs e)
{
}

How to Bind Data Source to Button Click Event in ASP.net

How do i bind a datasource to a button ,when i run this the grid view does not populate.
C# CODE
protected void Button1_Click(object sender, EventArgs e)
{
GridView1.DataSource = SqlDataSource1;
GridView1.DataBind();
}
You're setting the wrong property.
protected void Button1_Click(object sender, EventArgs e)
{
GridView1.DataSourceObject = SqlDataSource1;
GridView1.DataBind();
}

Initial selection for a DropDownList overriding user selection

I'm trying to set an initial selection for a DropDownList by calling: drop.SelectedIndex = 5 in Page_Load.
This works, but then if I change the selection manually and want to save the form, I'm still getting the initial selection instead of the new selection when calling drop.SelectedValue. What's wrong?
You have forgotten you check if(!IsPostback). Otherwise you will select the 6th item again on postbacks before the SelectedIndexChanged event is triggered (or a button-click event):
protected void Page_Load(Object sender, EventArgs e)
{
if(!IsPostBack) // do this only on the initial load and not on postbacks
dropDwonList1.SelectedIndex = 5;
}
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
//set up data here
}
}
if (Page.IsPostBack)
{
//do page reload logic in here
}
protected void foo(object sender, EventArgs e)
{
//get your selected value here
}
Try this code
You should be using if(!IsPostback) in the Page_Load function.
protected void Page_Load(Object sender, EventArgs e)
{
if(!IsPostBack)
{
drop.SelectedIndex = 5;
//yourcode
}
}
Through this your problem will be solved

How to optimize code if ViewState turned off?

protected void Page_Init(object sender, EventArgs e)
{ }
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
DropDownList1.DataSource = SomeObject.GetData();
DropDownList1.DataBind();
} }
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
var selvalue = DropDownList1.SelectedValue;
DoSomething(selvalue);
}
Please some body help me to make works properly this code if ViewState turned off.
If you turn the viewstate off, then you need to rebind the data on every trip to the server and before the page initializes.
Example of a dropdownlist without viewstate

ASP.NET Profile

I have this:
protected void Page_Load(object sender, EventArgs e)
{
nome_Txt.Text = Profile.dados_pessoais.nome;
}
protected void save_Click(object sender, EventArgs e)
{
Profile.dados_pessoais.nome = nome_Txt.Text;
}
If Profile.dados_pessoais.nome is empty, nome_txt.Text is empty too. When I change nome_Txt.Text to teste for example, when I click on the button nome_Txt.Text is empty.
What am I doing wrong?
The Page_Load event run before the button click event so you always assign the text box to empty value.
To solve this, don't populate the textbox when you are in a Postback:
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
nome_Txt.Text = Profile.dados_pessoais.nome;
}
}
As also stated in a comment, you probably have to save the profile after changing it otherwise it won't be saved when you next load the page:
protected void save_Click(object sender, EventArgs e)
{
Profile.dados_pessoais.nome = nome_Txt.Text;
Profile.Save()
}

Resources