检查 TextBox 输入是否为十进制数 - C#
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Check if TextBox input is a decimal number or not - C#
提问by Smith
My Goal:I want textbox to accept the decimal numbers like 123.45 or 0.45 or 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.
我的目标：我希望文本框接受十进制数字，如 123.45 或 0.45 或 1004.72。如果用户键入 a 或 b 或 c 等字母，程序应显示一条消息，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. How do I make my text box check for decimal numbers? Following is my code:
我的问题：我的代码只检查像 1003 或 567 或 1 这样的数字。它不检查像 123.45 或 0.45 这样的十进制数字。如何让我的文本框检查十进制数字？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，提前感谢您的帮助。:)
采纳答案by user2711965
use Decimal.TryParseto check if the string entered is decimal or not.
用于Decimal.TryParse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;
}
回答by arun
decimal.Tryparse returns true for string containing "," character and for example string like "0,12" returns true.
decimal.Tryparse 对于包含“,”字符的字符串返回真，例如像“0,12”这样的字符串返回真。
回答by KIRAN PRAJAPATI
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`
}
