C#DataGridView和数值数据 [英] C# DataGridView and Numeric data

问题描述

嗨
我的C#应用​​程序中有一个datagridview，它绑定到一组用户定义的对象.我对象中的某些数据项是数字数据类型-特定于float和uint.数据gridview已填充数据，我正在进行单元级数据验证.

验证期间，任何时候我尝试使用Convert.ToSingle()或Convert.ToUInt16()转换数据，并且如果输入单元格值为"0"，则会出现输入字符串格式不正确"的异常.但是，如果我的单元格值为"00"或任何其他非零数值，则转换函数(Convert.ToSingle()或Convert.ToUInt16())成功.

我不明白为什么Convert.ToSingle()或Convert.ToUInt16()的"0"输入值会引发格式异常.知道我应该怎么做才能防止这种异常吗?感谢您的帮助！

谢谢
K

Hi
I have a datagridview in my C# application which is bound to an array of user defined objects. Some of the data items in my objects are numeric data type - float and uint to be specific. The data gridview has been populated with data and I am doing the cell level data validation.

During validation, anytime I try to convert data by using Convert.ToSingle() or Convert.ToUInt16(), and if the input cell value is "0", I get a "Input String was not in a correct format" exception. But if my cell value is "00" or any other non-zero numeric value, the convert functions (Convert.ToSingle() or Convert.ToUInt16()) are successful.

I do not understand why "0" input value for Convert.ToSingle() or Convert.ToUInt16() will throw a format exception. Any idea what I should do to prevent this exception? I appreciate any help!

Thanks
K

推荐答案

我怀疑是您的其他代码有问题-我在下面的代码中尝试了此操作，没有问题.检查您实际上是否在访问正确的单元格，并在必要时发布代码片段.可能值得使用Singe.TryParse而不是Convert.ToSingle，因为它是通过bool报告问题的，而不是通过用户输入来报告问题.

I suspect that it''s your other code that is the problem - I tried it here with the code below and had no problem. Check you are actually accessing the right cell, and post a code fragment if necessary. It may be worth your using Singe.TryParse rather than Convert.ToSingle, as that reports problems via a bool, rather than excepting on user input.

String s = "0";
Single si = Convert.ToSingle(s);
if (Single.TryParse(s, out si))
    {
    ...
    }

您好
感谢您的答复.我尝试了您发布的代码，但在Convert.ToSingle(s)中仍然存在异常.然后，当我将硬编码字符串设置为"0"时，我对Convert.ToSingle(s)进行了注释，TryParse()成功了.

但是TryParse()在datagridview输入为"0"时不成功.这是一段代码，它给了我这个问题:

Hi
Thank you for your response. I tried the piece of code you posted, I still have the exception raised in Convert.ToSingle(s). Then I commented Convert.ToSingle(s) and the TryParse() was successful, when I had the hardcoded string as "0".

But the TryParse() is not successful with the datagridview input as "0". Here is the piece of code, which is giving me the issue:

private void LKDataGridView_CellValidating(object sender,
           DataGridViewCellValidatingEventArgs CellEvent)
{
    Single TempFloatVal = 0.0f;
    switch ((ELKCol) CellEvent.ColumnIndex)
    {

      case ELKCol.Delta:
         if (Single.TryParse(CellEvent.FormattedValue.ToString(),
                               out TempFloatVal))
             MessageBox.Show("Value of Delta: " +
                              TempFloatVal.ToString());
         else
             MessageBox.Show("Input value: " +
                   CellEvent.FormattedValue.ToString());

          break;

       default:   break


     }
}

"Delta"的数据类型为float.每当我在datgridview中为Delta输入非零数值时，Single.TryParse()都会成功.每当我在datgridview中为Delta输入0值时，Single.TryParse()都会失败.

我只是无法弄清楚发生了什么.任何建议都非常感谢！

谢谢
K

The data type for "Delta" is float. Any time i have non-zero numeric value entered for Delta in datgridview, Single.TryParse() succeeds. Any time I enter a 0 value for Delta in datgridview, Single.TryParse() fails.

I just am not able to figure out what is going on. Any suggestions is very much appreciated!

Thanks
K

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