[英]Check if TextBox input is a decimal number or not - C#
My Goal: I want textbox to accept the decimal numbers like 123.45 or 0.45 or 1004.72. 我的目标:我希望文本框接受十进制数字,例如123.45或0.45或1004.72。 If the user types in letters like a or b or c, the program should display a message alerting the user to input only numbers.
如果用户键入字母,例如a或b或c,程序将显示一条消息,提醒用户仅输入数字。
My Problem: My code only checks for numbers like 1003 or 567 or 1. It does not check for decimal numbers like 123.45 or 0.45. 我的问题:我的代码仅检查数字1003或567或1。它不检查十进制数字123.45或0.45。 How do I make my text box check for decimal numbers?
如何使我的文本框检查十进制数字? Following is my code:
以下是我的代码:
namespace Error_Testing
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
string tString = textBox1.Text;
if (tString.Trim() == "") return;
for (int i = 0; i < tString.Length; i++)
{
if (!char.IsNumber(tString[i]))
{
MessageBox.Show("Please enter a valid number");
return;
}
}
//If it get's here it's a valid number
}
}
}
I am a newbie and Thanks for your help in advance. 我是新手,感谢您的提前帮助。 :)
:)
use Decimal.TryParse
to check if the string entered is decimal or not. 使用
Decimal.TryParse
来检查输入的字符串是否为十进制。
decimal d;
if(decimal.TryParse(textBox1.Text, out d))
{
//valid
}
else
{
//invalid
MessageBox.Show("Please enter a valid number");
return;
}
decimal.Tryparse对于包含“,”字符的字符串返回true,例如,类似“ 0,12”的字符串返回true。
private void txtrate_TextChanged_1(object sender, EventArgs e)
{
double parsedValue;
decimal d;
// That Check the Value Double or Not
if (!double.TryParse(txtrate.Text, out parsedValue))
{
//Then Check The Value Decimal or double Becouse The Retailler Software Tack A decimal or double value
if (decimal.TryParse(txtrate.Text, out d) || double.TryParse(txtrate.Text, out parsedValue))
{
purchase();
}
else
{
//otherwise focus on agin TextBox With Value 0
txtrate.Focus();
txtrate.Text = "0";
}
}
else
{
// that function will be used for calculation Like
purchase();
/* if (txtqty.Text != "" && txtrate.Text != "")
{
double rate = Convert.ToDouble(txtrate.Text);
double Qty = Convert.ToDouble(txtqty.Text);
amt = rate * Qty;
}*/
}`enter code here`
}
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