字符串为空时，将字符串值替换为“ 0” [英] Replace string value with '0' when string is empty

问题描述

我要从文本框中获取一个值并将其转换为十进制。但是，文本框值可以为空。因此，我该如何处理文本框中的空字符串？

I'm taking a value from a textbox and converting it to decimal. But, the textbox value could be empty. So, how could I handle empty strings from the textbox?

不幸的是，我有大约50个文本框要处理，因此诸如在IF条件下检查null这样的答案就可以了。帮帮我。如果我使用所有这些IF条件，我的代码将很难看。

Unfortunately I have around 50 textboxes to deal with, so answers like 'check for null with IF condition' won't help me. My code will look ugly if I use all those IF conditions.

我有这个

Convert.ToDecimal(txtSample.Text)

要处理空值，我这样做了

To handle nulls, I did this

Convert.ToDecimal(txtSample.Text = string.IsNullOrEmpty(txtSample.Text) ? "0" : txtSample.Text)

但是，上面的代码在文本框中显示为 0。用户不想看到 0。另一个解决方案是将文本框值转换为变量，然后将变量转换如下。

But, the above code is displaying '0' in the textbox. User does not want to see '0'. Another solution is to take text box value into a variable and convert the variable like below.

string variable = txtSample.Text;
Convert.ToDecimal(variable = string.IsNullOrEmpty(variable) ? "0" : variable)

<但是，我不想定义大约50个变量。我正在寻找一段在转换过程中处理空值而不添加多余代码的代码。

But again, I do not want to define around 50 variables. I am looking for some piece of code that handles null values during conversion without adding the extra line of code.

推荐答案

但是，以上代码在文本框中显示为 0。用户不想看到 0。

But, the above code is displaying '0' in the textbox. User does not want to see '0'.

这是因为您的语句将新值分配给 txtSample.Text （当您执行 txtSample.Text = ... 时）。只需删除分配：

This is because your statement is assigning the new value to txtSample.Text (when you do txtSample.Text = ...). Just remove the assignment:

Convert.ToDecimal(string.IsNullOrEmpty(txtSample.Text) ? "0" : txtSample.Text)

如果要处理的文本字段很多，可以使事情变得简单，可以定义扩展方法：

To make things easier if you have many text fields to handle, you can define an extension method :

public static string ZeroIfEmpty(this string s)
{
    return string.IsNullOrEmpty(s) ? "0" : s;
}

并像这样使用它：

Convert.ToDecimal(txtSample.Text.ZeroIfEmpty())

这篇关于字符串为空时，将字符串值替换为“ 0”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！