C# int.Parse，输入字符串的格式不正确
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int.Parse, Input string was not in a correct format
提问by user575219
How would I parse an empty string? int.Parse(Textbox1.text)gives me an error:
我将如何解析空字符串？int.Parse(Textbox1.text)给我一个错误：
Input string was not in a correct format.
System.FormatException: Input string was not in a correct format.
输入字符串的格式不正确。
System.FormatException: 输入字符串的格式不正确。
If the text is empty (Textbox1.text = ''), it throws this error. I understand this error but not sure how to correct this.
如果文本为空 ( Textbox1.text = '')，则会引发此错误。我理解这个错误，但不知道如何纠正这个错误。
采纳答案by userx
If you're looking to default to 0 on an empty textbox (and throw an exception on poorly formatted input):
如果您希望在空文本框中默认为 0（并在格式错误的输入上引发异常）：
int i = string.IsNullOrEmpty(Textbox1.Text) ? 0 : int.Parse(Textbox1.Text);
If you're looking to default to 0 with any poorly formatted input:
如果您希望将任何格式错误的输入默认为 0：
int i;
if (!int.TryParse(Textbox1.Text, out i)) i = 0;
回答by xandercoded
if(!String.IsNullOrEmpty(Textbox1.text))
var number = int.Parse(Textbox1.text);
Or even better:
或者甚至更好：
int number;
int.TryParse(Textbox1.Text, out number);
回答by Ry-
Well, what do you wantthe result to be? If you just want to validate input, use int.TryParseinstead:
嗯，你希望结果是什么？如果您只想验证输入，请int.TryParse改用：
int result;
if (int.TryParse(Textbox1.Text, out result)) {
// Valid input, do something with it.
} else {
// Not a number, do something else with it.
}
回答by Victor Chekalin
Try this:
尝试这个：
int number;
if (int.TryParse(TextBox1.Text, out number))
{
//Some action if input string is correct
}
回答by SolidSnake
you can wrap it with simple try/catch...
你可以用简单的try/catch...
回答by devinbost
You could also use an extension method like this:
您还可以使用这样的扩展方法：
public static int? ToNullableInt32(this string s)
{
int i;
if (Int32.TryParse(s, out i)) return i;
return null;
}
Here's the reference: How to parse a string into a nullable int in C# (.NET 3.5)
这是参考：How to parse a string into a nullable int in C# (.NET 3.5)
回答by Deepu Reghunath
If the input is a number or an empty string this will work. It will return zero if the string is empty or else it will return the actual number.
如果输入是数字或空字符串，这将起作用。如果字符串为空，它将返回零，否则将返回实际数字。
int.Parse("0"+Textbox1.Text)
