Question

我在文本框中有这个号码“84,8441546842904”如何在按钮点击事件中转换为84,8或84,84？

Answer 1

如果这意味着您要解析该值并将其四舍五入到一定数量的小数位：

double value = Math.Round(double.Parse(textbox.Text), 2);

将解析文本并将其四舍五入到小数点后两位。解析时可能需要使用System.Globalization.CultureInfo对象来考虑本地区域文化的数字格式。

请参阅http://msdn.microsoft.com/en-us/library/75ks3aby.aspx

Answer 2

看起来你似乎试图将数字修剪为1或2精度（不是'，'在某些国家用作美国'。'？）。如果这是您所追求的，您可以使用Double.Parse将其转换为Double，然后查看描述为here的字符串格式选项，将其格式化回文本框。

Answer 3

我使用这种函数来验证用户输入。

此问题的解决方法也尊重用户文化数字格式！

namespace Your_App_Namespace
{

public static class Globals
{
    public static double safeval = 0; // variable to save former value!

    public static bool isPositiveNumeric(string strval, System.Globalization.NumberStyles NumberStyle)
    // checking if string strval contains positive number in USER CULTURE NUMBER FORMAT!
    {
        double result;
        boolean test;
        if (strval.Contains("-")) test = false;
        else test = Double.TryParse(strval, NumberStyle, System.Globalization.CultureInfo.CurrentCulture, out result);
               // if (test == false) MessageBox.Show("Not positive number!");
        return test;
    }

    public static string numstr2string(string strval, string nofdec)
    // conversion from numeric string into string in USER CULTURE NUMBER FORMAT!
    // call example numstr2string("12.3456", "0.00") returns "12.34"
    {
        string retstr = 0.ToString(nofdec);
        if (Globals.isPositiveNumeric(strval, System.Globalization.NumberStyles.Number)) retstr = double.Parse(strval).ToString(nofdec);
        else retstr = Globals.safeval.ToString(nofdec);
        return retstr;
    }

    public static string number2string(double numval, string nofdec)
    // conversion from numeric value into string in USER CULTURE NUMBER FORMAT!
    // call example number2string(12.3456, "0.00") returns "12.34"
    {
        string retstr = 0.ToString(nofdec);
        if (Globals.isPositiveNumeric(numval.ToString(), System.Globalization.NumberStyles.Number)) retstr = numval.ToString(nofdec);
        else retstr = Globals.safeval.ToString(nofdec);
        return retstr;
    }
}

// Other Your_App_Namespace content

}

    // This is the way how to use those functions

    // function to call when TextBox GotFocus
    private void textbox_clear(object sender, System.Windows.RoutedEventArgs e)
    {
        TextBox txtbox = e.OriginalSource as TextBox;
        // save original value
        Globals.safeval = double.Parse(txtbox.Text);
        txtbox.Text = "";
    }

    // function to call when TextBox LostFocus
    private void textbox_change(object sender, System.Windows.RoutedEventArgs e)
    {
        TextBox txtbox = e.OriginalSource as TextBox;
        // text from textbox into sting with checking and string format
        txtbox.Text = Globals.numstr2string(txtbox.Text, "0.00");
    }

Answer 4

double i = 0;
if (double.TryParse(tbxNumber.Text,out i)) {
    MessageBox.Show("number is " + i.ToString());
}

从文本框中删除数字

4 个答案: