What I tried:
MarkUP:
<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
<asp:Label ID="Label1" runat="server" AssociatedControlID="TextBox2" Text="Label"></asp:Label>
<asp:SliderExtender ID="SliderExtender1" TargetControlID="TextBox2" BoundControlID="Label1" Maximum="200" Minimum="100" runat="server">
</asp:SliderExtender>
Code Behind:
protected void setImageWidth()
{
int imageWidth;
if (Label1.Text != null)
{
imageWidth = 1 * Convert.ToInt32(Label1.Text);
Image1.Width = imageWidth;
}
}
After running the page on a browser, I get the System.FormatException
: Input string was not in a correct format.
The problem is with line
imageWidth = 1 * Convert.ToInt32(Label1.Text);
Label1.Text
may or may not be int. Check.
Use Int32.TryParse(value, out number)
instead. That will solve your problem.
int imageWidth;
if(Int32.TryParse(Label1.Text, out imageWidth))
{
Image1.Width= imageWidth;
}
Because Label1.Text
is holding Label
which can't be parsed into integer, you need to convert the associated textbox's text to integer
imageWidth = 1 * Convert.ToInt32(TextBox2.Text);
If using TextBox2.Text
as the source for a numeric value, it must first be checked to see if a value exists, and then converted to integer.
If the text box is blank when Convert.ToInt32
is called, you will receive the System.FormatException
. Suggest trying:
protected void SetImageWidth()
{
try{
Image1.Width = Convert.ToInt32(TextBox1.Text);
}
catch(System.FormatException)
{
Image1.Width = 100; // or other default value as appropriate in context.
}
}
Replace with
imageWidth = 1 * Convert.ToInt32(Label1.Text);
Source: Stackoverflow.com