空文本框被视为空字符串还是 null?

问题描述

有问题的文本框包含在我的代码中的 if 语句中，其效果是

The text box in question is involved in an if statement within my code, something to the effect of

if (textbox.text != "") 
{
    do this
}

我很好奇空文本框是否会被视为空字符串或空语句.

I am curious if an empty text box will be considered an empty string or a null statement.

推荐答案

尝试使用 IsNullOrWhiteSpace，这将确保验证空白也无需修剪.

Try to use IsNullOrWhiteSpace, this will make sure of validating the whitespace too without having to trim it.

if (!string.IsNullOrWhiteSpace(textbox.Text))
{
    //code here
}

根据文档 string.IsNullOrWhiteSpace 计算结果为:

According to documentation string.IsNullOrWhiteSpace evaluates to:

return String.IsNullOrEmpty(value) || value.Trim().Length == 0;

String.IsNullOrWhiteSpace:

指示指定的字符串是否为空、空或仅由空白字符组成.

Indicates whether a specified string is null, empty, or consists only of white-space characters.

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