Find a value in List<>

Question

i have a problem when i want to find value in List<> but i am not getting the integer value. Here is my code from that i want to find the value in the List .

private void txtnapsaserach_TextChanged(object sender, EventArgs e)
{
    try
    {
       //decimal find = decimal.Parse(txtnapsaserach.Text);

       if (decimal.Parse(txtnapsaserach.Text) > 0)
       {
       List<NapsaTable> _napsatabs = this.napsaTableBindingSource.List as List<NapsaTable>;
       this.napsaTableBindingSource.DataSource = 
        _napsatabs.Where(p =>p.NapsaRate.Equals(txtnapsaserach.Text)).ToList();

       }
    }
    catch (Exception Ex)
    {
    }
}

Is any solution for me . Because this works for me when i try to find string value.

Thanks in advance.

Answer 1

You are comparing string object (text of txtnapsasearch) with float object (value of NapsaRate property) here:

Where(p =>p.NapsaRate.Equals(txtnapsaserach.Text))

Which of course returns false (because objects have different types). Parse text to float instead and use float to filter out napsatabs list:

private void txtnapsaserach_TextChanged(object sender, EventArgs e)
{
     float value;
     if (!float.TryParse(txtnapsaserach.Text, out value))
         return; // return if text cannot be parsed as float number

     if (value > 0)
     {
        var napsatabs = napsaTableBindingSource.List as List<NapsaTable>;
        napsaTableBindingSource.DataSource = 
            napsatabs.Where(p =>p.NapsaRate == value).ToList();
     }
}

BTW be careful with usage of Equals. Here is how Equals implemented for float (and other types)

public override bool Equals(object obj)
{
    if (!(obj is float))
    {
        return false; // your case if obj is string
    }
    float f = (float) obj;
    return ((f == this) || (IsNaN(f) && IsNaN(this)));
}

As you can see, you can pass any object here. But comparison will occur only if passed object also float.