乘以值时，输入字符串的格式不正确 [英] Input string was not in a correct format when multiplying values

问题描述

在将标签文本转换为整数并乘以时，输入字符串不正确...



我尝试过：

  private   void  GrandTotal（）
 {
  int  GTotal =  0 ; 
  for （ int  i =  0 ; i <  BillingGridView.Rows.Count; i ++）
 {
  String  total =（BillingGridView.Rows [i] .Cells [ 7 ]。Text）; 
 GTotal + = Convert.ToInt32（total.ToString（））; 
} 
 BillTotalLabel.Text = GTotal.ToString（）; 
  if （BillTotalLabel.Text！=   ）
 {
  int  billtotal = Convert.ToInt32（BillTotalLabel.Text）; 
  int  vat = Convert.ToInt32（VATPerLabel.Text.ToString（））; 
  int  totalaftervat = billtotal * vat / 100; 
 VATValueLabel.Text = totalaftervat.ToString（）; 
} 
} 

解决方案

@NotPoliticallyCorrect指出了你正确的方向 - 其中一个的内容textboxes不是一个整数。



使用 Convert.ToInt32 的问题在于它会像你一样发现，如果字符串不是整数，则抛出异常。例如1就可以了，12345就可以，但是

35和14.6都会导致你观察到的失败。



更好的解决方案是使用整数解析方法之一 - 参见如何：将字符串转换为数字（C＃编程指南） [ ^ ]



您的代码还有其他问题...

  string  total =（BillingGridView.Rows [i] .Cells [ 7 ]。Text）; 

为我抛出一个编译错误，它应该是

  String  total =（BillingGridView.Rows [i] .Cells [ 7 ]。Value.ToString（））; 

行

 int vat = Convert.ToInt32（VATPerLabel.Text.ToString（））; 

在其中有一个不必要的 .ToString（）调用... VATPerLabel.Text 已经是一个字符串！类似地

 GTotal + = Convert.ToInt32（total.ToString（））; 

不需要 .ToString（）因为您已经将总计声明为字符串。



行

  int  billtotal = Convert.ToInt32（BillTotalLabel.Text）; 

有不必要的转换它...你刚刚将BillTotalLabel.Text设置为 GTotal.ToString（）; 这样该行应该是

  int  billtotal = GTotal; 

所以你应该有这样的东西（注意我还没有测试过这个）

  private   void  GrandTotal（）
 {
  int  GTotal =  0 ; 
  int  res; 
  for （ int  i =  0 ; i <  BillingGridView.Rows.Count; i ++）
 {
  String  total =（BillingGridView.Rows [i] .Cells [ 7 ]。Value.ToString（））; 
  if （ int  .TryParse（total， out  res））
 GTotal + = Convert.ToInt32（total）; 
} 
 BillTotalLabel.Text = GTotal.ToString（）; 
 VATValueLabel.Text =  ; 
  if （ String  .IsNullOrWhiteSpace（BillTotalLabel.Text））
 返回; 
 
  int  billtotal = GTotal; 
  int  vat; 
  if （ int  .TryParse（VATPerLabel.Text， out 增值税））
 {
  int  totalaftervat = billtotal * vat / 100; 
 VATValueLabel.Text = totalaftervat.ToString（）; 
} 
} 
 

我会留下最后一条评论 - 我认为你不想使用 int 对于其中一些变量 - 十进制或双精度可能更合适

如果空间或某些角色即将到来，请放置适当的修剪。

get input string was not in correct for when converting label text to integer and multiplying...

What I have tried:

private void GrandTotal()
    {
        int GTotal = 0;
        for (int i = 0; i < BillingGridView.Rows.Count; i++)
        {
            String total = (BillingGridView.Rows[i].Cells[7].Text);
            GTotal += Convert.ToInt32(total.ToString());
        }
        BillTotalLabel.Text = GTotal.ToString();
        if (BillTotalLabel.Text != "")
        {
            int billtotal = Convert.ToInt32(BillTotalLabel.Text);
            int vat = Convert.ToInt32(VATPerLabel.Text.ToString());
            int totalaftervat = billtotal * vat/100;
            VATValueLabel.Text = totalaftervat.ToString();
        }
    }

解决方案

@NotPoliticallyCorrect has pointed you in the right direction - the content of one of the textboxes is not an integer.

The problem with using Convert.ToInt32 is that it will, as you have discovered, throw an exception if the string is not an integer. For example "1" will be ok, "12345" will be ok but both "

35" and "14.6" will cause the failure you have observed.

A better solution is to use one of the integer parsing methods - see How to: Convert a String to a Number (C# Programming Guide)[^]

There are other issues with your code ...

string total = (BillingGridView.Rows[i].Cells[7].Text);

is throwing a compile error for me, it should probably be

String total = (BillingGridView.Rows[i].Cells[7].Value.ToString());

The line

int vat = Convert.ToInt32(VATPerLabel.Text.ToString());

has an unnecessary .ToString() call in it ... VATPerLabel.Text is already a string! Similarly

GTotal += Convert.ToInt32(total.ToString());

doesn't need the .ToString() as you have already declared total as a String.

The line

int billtotal = Convert.ToInt32(BillTotalLabel.Text);

has an unnecessary conversion in it ... you have just set the BillTotalLabel.Text to be GTotal.ToString();so that line should be

int billtotal = GTotal;

So you should have something like this (note I have not tested this)

private void GrandTotal()
{
    int GTotal = 0;
    int res;
    for (int i = 0; i < BillingGridView.Rows.Count; i++)
    {
        String total = (BillingGridView.Rows[i].Cells[7].Value.ToString());
        if(int.TryParse(total, out res))
            GTotal += Convert.ToInt32(total);
    }
    BillTotalLabel.Text = GTotal.ToString();
    VATValueLabel.Text = "";
    if (String.IsNullOrWhiteSpace(BillTotalLabel.Text))
        return;

    int billtotal = GTotal;
    int vat;
    if (int.TryParse(VATPerLabel.Text, out vat))
    {
        int totalaftervat = billtotal*vat/100;
        VATValueLabel.Text = totalaftervat.ToString();
    }
}

I will leave you with one final comment - I don't think you want to be using int for some of these variables - decimal or double might be more appropriate

Place proper trim if space or some character is coming.

这篇关于乘以值时，输入字符串的格式不正确的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！