c#--control text box can only enter integers (including decimals)

//control controls Enter a positive number (including decimals)        Private voidTxt_weight_keypress (Objectsender, KeyPressEventArgs e) {            //The first step: Determine whether the input is a digital--char. Isnumber (E.keychar)//if it is a number, you can enter (E. Handled = false;)//if it is not a number, determine if it is a decimal point            if(Char. Isnumber (E.keychar)) {e.handled=false; }            Else            {                //determines whether the input is a decimal point, or a period in the Chinese state, or a backspace//if it is a decimal point, the loop determines whether each character is a decimal point, if there is no input if there is no input allowed//If the BACKSPACE key, allow input--if (E.keychar = = ' \b ')//if it is not a decimal point and is not a backspace key, the input is not allowed                if(E.keychar = = Convert.tochar (". ") || E.keychar = = Convert.tochar ("."))                {                    intI_d =0;  for(inti =0; i < txt_Weight.Text.Length; i++)                    {                        if(Txt_Weight.Text.Substring (I,1) ==".") {e.handled=true; I_d++; return; }                    }                    if(I_d = =0)                    {
E.keychar = Convert.tochar (".");                        /Set the key input value to "." E.handled=false; }                }                Else if(E.keychar = ='\b') {e.handled=false; }                Else{e.handled=true; }            }        }

c#--control text box can only enter integers (including decimals)