C# 如果文本中有百分号，则计算百分比

我的项目有一个名为txtdisc的文本框字段。我需要从另一个名为txttotal的文本框中减去输入的值。问题是如果我输入百分号，我需要减去百分比。例如，如果我的总值为1000，折扣值为2，则我需要答案为998，如果输入的值为2%，则我需要值为980。我使用

\u textchanged

事件进行计算

我的代码是：

private void txtdiscount_TextChanged(object sender, EventArgs e)
{
  if (txtdiscount.Text.Length > 0 && lbltotal.Text != "")
  {
    decimal net = 0, total = 0, discount = 0;
    total = Convert.ToDecimal(lbltotal.Text);
    discount = Convert.ToDecimal(txtdiscount.Text);
    net =total- discount;
    lblnetamount.Text = net.ToString();
  }
}

试试这个：

private void txtdiscount_TextChanged(object sender, EventArgs e)
{
    if (txtdiscount.Text.Length > 0 && lbltotal.Text != "")
    {
        decimal net = 0, total = 0, discount = 0;
        total = Convert.ToDecimal(lbltotal.Text);
        discount = Convert.ToDecimal(txtdiscount.Text.Replace("%",""));
        if(txtdiscount.Text.EndsWith("%")
           discount = total * (discount/100);
        net = total- discount;
        lblnetamount.Text = net.ToString();
    }
}

说明：

如果你的文本中有%，只需将其去掉即可

if(txtdiscount.Text.EndsWith("%")
           discount = total * (discount/100);

如果txtdiscount.Text以%结尾，则计算百分比折扣，否则保留折扣

重要

我建议您改用decimal.TryParse方法或Convert.ToDecimal

尝试以下方法：

private void txtdiscount_TextChanged(object sender, EventArgs e)
{
    if (txtdiscount.Text.Length > 0 && lbltotal.Text != "")
    {
        decimal net = 0, total = 0, discount = 0;
        total = Convert.ToDecimal(lbltotal.Text);
        discount = Convert.ToDecimal(txtdiscount.Text.Replace("%",""));
        if(txtdiscount.Text.EndsWith("%")
           discount = total * (discount/100);
        net = total- discount;
        lblnetamount.Text = net.ToString();
    }
}

        int discount, total = 1000, net;
        if(txtdiscount.EndsWith("%"))
                 discount  = total*Convert.ToInt32(txtdiscount.Substring(0, st.Length-1))/100;
        else
                 discount  =Convert.ToInt32(txtdiscount.Substring(0, st.Length-1));
        net = total -discount; 

说明：

如果你的文本中有%，只需将其去掉即可

if(txtdiscount.Text.EndsWith("%")
           discount = total * (discount/100);

如果txtdiscount.Text以%结尾，则计算百分比折扣，否则保留折扣

重要

我建议您改用decimal.TryParse方法或Convert.ToDecimal方法

        int discount, total = 1000, net;
        if(txtdiscount.EndsWith("%"))
                 discount  = total*Convert.ToInt32(txtdiscount.Substring(0, st.Length-1))/100;
        else
                 discount  =Convert.ToInt32(txtdiscount.Substring(0, st.Length-1));
        net = total -discount; 

这里我们只是检查字符串是否以“%”结尾。如果是的话，我们将其剥离，并计算其占总数的百分比

---

这里我们只是检查字符串是否以“%”结尾。如果是，我们将其剥离并计算总数的百分比。

您可以使用

Contains

如果找到，可以使用

修剪（'%'）将其删除。

然后修改计算以进行百分比计算

 if (txtdiscount.Text.Length > 0 && lbltotal.Text != "")
     {
        decimal net = 0, total = 0, discount = 0;
        total = Convert.ToDecimal(lbltotal.Text);
        if (txtdiscount.Contains("%"))
        {
           discount = Convert.ToDecimal(txtdiscount.Text.Trim('%'));
           net = total - (total * (discount / 100));
        }
        else
        {
           discount = Convert.ToDecimal(txtdiscount.Text);
           net = total - discount;
        }
        lblnetamount.Text = net.ToString();

     }

资源

---

您可以使用

Contains

如果找到，可以使用

修剪（'%'）将其删除。

然后修改计算以进行百分比计算

 if (txtdiscount.Text.Length > 0 && lbltotal.Text != "")
     {
        decimal net = 0, total = 0, discount = 0;
        total = Convert.ToDecimal(lbltotal.Text);
        if (txtdiscount.Contains("%"))
        {
           discount = Convert.ToDecimal(txtdiscount.Text.Trim('%'));
           net = total - (total * (discount / 100));
        }
        else
        {
           discount = Convert.ToDecimal(txtdiscount.Text);
           net = total - discount;
        }
        lblnetamount.Text = net.ToString();

     }

资源

请尝试以下代码：

使用

Contains（）

 private void txtdiscount_TextChanged(object sender, EventArgs e)
  {
     if (txtdiscount.Text.Length > 0 && lbltotal.Text != "")
     {
        decimal net = 0, total = 0, discount = 0;
        total = Convert.ToDecimal(lbltotal.Text);
        if(txtdiscount.Text.Contains('%'))
        {
          discount = Convert.ToDecimal(txtdiscount.Text.split('%')[0]);
          net = total - total*discount/100;
        }
        else
        {
          discount = Convert.ToDecimal(txtdiscount.Text);
          net =total- discount;
        }
        lblnetamount.Text = net.ToString();
     }
  }

希望它能帮助您
尝试以下代码：

使用
Contains（）

 private void txtdiscount_TextChanged(object sender, EventArgs e)
  {
     if (txtdiscount.Text.Length > 0 && lbltotal.Text != "")
     {
        decimal net = 0, total = 0, discount = 0;
        total = Convert.ToDecimal(lbltotal.Text);
        if(txtdiscount.Text.Contains('%'))
        {
          discount = Convert.ToDecimal(txtdiscount.Text.split('%')[0]);
          net = total - total*discount/100;
        }
        else
        {
          discount = Convert.ToDecimal(txtdiscount.Text);
          net =total- discount;
        }
        lblnetamount.Text = net.ToString();
     }
  }

希望它能帮助您
您可以使用此代码

private void txtdiscount_TextChanged(object sender, EventArgs e)
{
   if (txtdiscount.Text.Length > 0 && lbltotal.Text != "")
   {
      decimal net = 0, total = 0, discount = 0;
      total = Convert.ToDecimal(lbltotal.Text);
      if (txtdiscount.Text.IndexOf('%') != -1)
      {
        discount = total *  Convert.ToDecimal(txtdiscount.Text.Split('%')[0])/100;
      }
      else
      {
        discount = Convert.ToDecimal(txtdiscount.Text);
      }
      net =total- discount;
      lblnetamount.Text = net.ToString();

    }
 }

你可以使用这个代码

private void txtdiscount_TextChanged(object sender, EventArgs e)
{
   if (txtdiscount.Text.Length > 0 && lbltotal.Text != "")
   {
      decimal net = 0, total = 0, discount = 0;
      total = Convert.ToDecimal(lbltotal.Text);
      if (txtdiscount.Text.IndexOf('%') != -1)
      {
        discount = total *  Convert.ToDecimal(txtdiscount.Text.Split('%')[0])/100;
      }
      else
      {
        discount = Convert.ToDecimal(txtdiscount.Text);
      }
      net =total- discount;
      lblnetamount.Text = net.ToString();

    }
 }

这可能是一个更好的方法：

private void txtdiscount_TextChanged(object sender, EventArgs e)
{
    if (!string.IsNullOrEmpty(txtdiscount.Text) && !string.IsNullOrEmpty(lbltotal.Text))
    {
        decimal net = 0, total = 0, discount = 0;
        total = decimal.TryParse(lbltotal.Text, out total);
        discount = decimal.TryParse(txtdiscount.Text.Replace("%",""), out discount);
        discount = txtdiscount.Text.EndsWith("%")?total * (discount/100):discount;
        net = total- discount;
        lblnetamount.Text = net.ToString();
    }
}

这可能是一个更好的方法：

private void txtdiscount_TextChanged(object sender, EventArgs e)
{
    if (!string.IsNullOrEmpty(txtdiscount.Text) && !string.IsNullOrEmpty(lbltotal.Text))
    {
        decimal net = 0, total = 0, discount = 0;
        total = decimal.TryParse(lbltotal.Text, out total);
        discount = decimal.TryParse(txtdiscount.Text.Replace("%",""), out discount);
        discount = txtdiscount.Text.EndsWith("%")?total * (discount/100):discount;
        net = total- discount;
        lblnetamount.Text = net.ToString();
    }
}

您应该始终在答案中添加信息以了解代码的作用。您应该始终在答案中添加信息以了解代码的作用。