WPF数字和字符串处理，日期处理

字符串

字符串占位符拼接

string.Format("[{0}] {1}", 10, "abc")

UUID

Guid.NewGuid().ToString()

时间戳

TimeSpan ts = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0);
string timestr = Convert.ToInt64(ts.TotalMilliseconds).ToString();

结果类似于

1648866151124

时间戳

/// <summary>
/// 返回一个时间戳到毫秒
/// </summary>
/// <returns>
/// </returns>
public static long Timestamp()
{
    TimeSpan ts = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0);
    long timestr = Convert.ToInt64(ts.TotalMilliseconds);
    return timestr;
}

/// <summary>
/// 返回一个时间戳到秒
/// </summary>
/// <returns>
/// </returns>
public static long TimestampTotalSeconds()
{
    TimeSpan ts = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0);
    long timestr = Convert.ToInt64(ts.TotalSeconds);
    return timestr;
}

日期格式化

DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss:ffff dddd"); // => 2016-05-09 13:09:55:2350 星期一

可用于路径

string timestr = DateTime.Now.ToString("yyyy-MM-dd-HH-mm-ss-ffff");
Console.WriteLine(timestr);

结果类似于

2022-04-02-10-05-02-3485

MD5

/*
*┌────────────────────────────────────────────────┐
*│　描    述：MD5Uitls
*│　作    者：剑行者
*│　版    本：1.0
*│　创建时间：2023/2/9 16:59:55
*└────────────────────────────────────────────────┘
*/

namespace ZUtils
{
    public class MD5Uitls
    {
        /// <summary>
        /// 字符串MD5加密
        /// </summary>
        /// <param name="Text">要加密的字符串</param>
        /// <returns>密文</returns>
        public static string MD5(string Text)
        {
            byte[] buffer = System.Text.Encoding.Default.GetBytes(Text);
            try
            {
                System.Security.Cryptography.MD5CryptoServiceProvider check;
                check = new System.Security.Cryptography.MD5CryptoServiceProvider();
                byte[] somme = check.ComputeHash(buffer);
                string ret = "";
                foreach (byte a in somme)
                {
                    if (a < 16)
                        ret += "0" + a.ToString("X");
                    else
                        ret += a.ToString("X");
                }
                return ret.ToLower();
            }
            catch
            {
                throw;
            }
        }
    }
}

字符串与字符互转

private string getVerfyCode()
{
  string mystr = DateTime.Now.ToString("yyyyMMddHH");
  char[] cArr = mystr.ToCharArray();
  Array.Reverse(cArr);
  mystr = "xhkj" + new string(cArr);
  mystr = MD5Uitls.MD5(mystr);
  if (mystr.Length >= 6)
  {
    mystr = mystr.Substring(0, 6);
  }
  return mystr;
}

字符串=>字符数组

char[] cArr = mystr.ToCharArray();

字符数组=>字符串

new string(cArr);

字符串数组是否包含

string[] strArr = { "小明", "小红" };
bool isContain = ((IList)strArr).Contains("小明");

Double保留几位小数

不四舍五入

只要求保留2位不四舍五入

public static double GetDouuble2f(double num)
{
    int temp = (int)(num * 100);
    return 1.0d * temp / 100;
}

四舍五入

方式1

Math.Round(0.55555,2)

方式2

decimal d=decimal.Round(decimal.Parse("0.55555"),2);

方式3

public static double GetDouuble2f(double num)
{
    //fN  保留N位，四舍五入 
    return double.Parse(num.ToString("f2"));
}

方式4

string  result  =  String.Format("{0:N2}",0.55555);//2位 
string  result  =  String.Format("{0:N3}",0.55555);//3位

方式5

double s = 55.55555;
string result = s.ToString("#0.00");//点后面几个0就保留几位 55.56

方式6

double dValue = 95.12567;
int iValue = 100;
string strValue = "95.12567";
string result = "";

result = Convert.ToDouble(dValue).ToString("0.00");//保留小数点后两位,结果为95.13
result = Convert.ToDouble(iValue).ToString("0.00");//100.00
result = Convert.ToDouble(strValue).ToString("0.00");//95.13
result = Convert.ToDouble(dValue).ToString("P");//得到小数点后2位的百分比,自动 加上%号;//9512.57%
result = Convert.ToDouble(strValue).ToString("f2");//保留小数点后2位; //95.13

Binding使用StringFormat格式化字符串

货币格式

<TextBlock Text="{Binding Price, StringFormat={}{0:C}}" /> // $123.46

货币格式，一位小数

<TextBox Text="{Binding Price, StringFormat={}{0:C1}}" /> // $123.5

前后文字

前文字

<TextBox Text="{Binding Price, StringFormat=单价：{0:C}}" /> //单价：$123.46

后文字

<TextBox Text="{Binding Price, StringFormat={}{0}元}" /> // 123.45678元

数字

固定的位数，位数不能少于未格式化前，仅支持整形

<TextBox Text="{Binding Count, StringFormat={}{0:D6}}" /> // 086723

指定小数点后的位数

<TextBox Text="{Binding Total, StringFormat={}{0:F4}}" /> // 28768234.9329

用分号隔开的数字，并指定小数点后的位数

<TextBox Text="{Binding Total, StringFormat={}{0:N3}}" /> // 28,768,234.933

格式化百分比

<TextBox Text="{Binding Persent, StringFormat={}{0:P1}}" /> // 78.9 %

<TextBlock Text="{Binding rate, StringFormat={}{0:F2}%}"/> // 78.66%

自定义格式化

整数不保留小数点后数字，小数才保留。

格式化转换类

using System;
using System.Globalization;

namespace SchoolClient.ValueConverters
{
    internal class NumConverter : System.Windows.Data.IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            double num = (double)value;
            double num2 = double.Parse(parameter.ToString());

            int temp_num = (int)Math.Pow(10.0, num2);
            double temp_num2 = (double)(int)(num * temp_num) / temp_num;
            return temp_num2 + "%";
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return null;
        }
    }
}

XAML中

原来的

<TextBlock Text="{Binding rate, StringFormat={}{0:f2}%}" />

替换为

<Window xmlns:conv="clr-namespace:SchoolClient.ValueConverters">
  <Window.Resources>
    <conv:NumConverter x:Key="num_conv" />
  </Window.Resources>
  <TextBlock Text="{Binding Path=rate, Converter={StaticResource num_conv}, ConverterParameter='2'}" />
</Window>

占位符

<TextBox Text="{Binding Price, StringFormat={}{0:0000.00}}" /> // 0123.46
<TextBox Text="{Binding Price, StringFormat={}{0:####.##}}" /> // 123.46

日期/时间

<TextBox Text="{Binding DateTimeNow, StringFormat={}{0:d}}" /> // 5/4/2015
<TextBox Text="{Binding DateTimeNow, StringFormat={}{0:D}}" /> // Monday, May 04, 2015
<TextBox Text="{Binding DateTimeNow, StringFormat={}{0:f}}" /> // Monday, May 04, 2015 5:46 PM
<TextBox Text="{Binding DateTimeNow, StringFormat={}{0:F}}" /> // Monday, May 04, 2015 5:46:56 PM
<TextBox Text="{Binding DateTimeNow, StringFormat={}{0:g}}" /> // 5/4/2015 5:46 PM
<TextBox Text="{Binding DateTimeNow, StringFormat={}{0:G}}" /> // 5/4/2015 5:46:56 PM
<TextBox Text="{Binding DateTimeNow, StringFormat={}{0:m}}" /> // May 04
<TextBox Text="{Binding DateTimeNow, StringFormat={}{0:M}}" /> // May 04
<TextBox Text="{Binding DateTimeNow, StringFormat={}{0:t}}" /> // 5:46 PM
<TextBox Text="{Binding DateTimeNow, StringFormat={}{0:T}}" /> // 5:46:56 PM
<TextBox Text="{Binding DateTimeNow, StringFormat={}{0:yyyy年MM月dd日}}" /> // 2015年05月04日
<TextBox Text="{Binding DateTimeNow, StringFormat={}{0:yyyy-MM-dd}}" /> // 2015-05-04
<TextBox Text="{Binding DateTimeNow, StringFormat={}{0:yyyy-MM-dd HH:mm}}" /> // 2015-05-04 17:46
<TextBox Text="{Binding DateTimeNow, StringFormat={}{0:yyyy-MM-dd HH:mm:ss}}" /> // 2015-05-04 17:46:56

或者

<TextBlock Text="{Binding Time,StringFormat='yyyy:MM:dd HH:mm:ss'}"/>

多重绑定

<TextBox.Text>
    <MultiBinding StringFormat="姓名：{0}{1}">
        <Binding Path="FristName" />
        <Binding Path="LastName" />
    </MultiBinding>
</TextBox.Text>

结果

姓名：AAbb

多重绑定中的特殊字符

<TextBox.Text>
    <MultiBinding StringFormat="姓名：{0}&#x09;{1}">
        <Binding Path="FristName" />
        <Binding Path="LastName" />
    </MultiBinding>
</TextBox.Text>

特殊符号

\a    BEL
\b    BS - Backspace
\f    FF - Formfeed
\n  
  LF, NL - Linefeed, New Line
\r  
  CR - Carriage return
\t  	  HT - Tab, Horizontal Tabelator
\v    VT - Vertical Tabelator

结果

姓名：AA bb