空文本框被视为空字符串还是 null?

Is an empty textbox considered an empty string or null?(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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