如何在进行自定义控制时允许空格？ [英] How to allow spaces while making custom control?

问题描述

你好!!

在我的学费结构项目中，我需要文本框包含字符串或整数值，所以为了这个目的，我为数字&对于字符，它工作正常，但它没有在两个字符串之间占用空间...

我的代码

hello!!
In my school fees structure project i need text boxes either contain string or int value so for that purpose i make my custom controls for numeric & for characters it is working properly but it is not taking space between two string...
my code

public class Class1 : TextBox
    {
        protected override void OnKeyPress(KeyPressEventArgs e)
        {


            if (char.IsNumber(e.KeyChar) == false)
            {
                if ((e.KeyChar == (char)Keys.Back)||(e.KeyChar==(char)Keys.Space))
                {
                    e.Handled = false;

                }
                else
                    e.Handled = true;
            }
        }
    }


    public class TextBoxAlphabetic : TextBox
    {
        protected override void OnKeyPress(KeyPressEventArgs e)
        {
            if (char.IsLetter(e.KeyChar) == false)
            {
                if ((e.KeyChar == (char)Keys.Back)||(e.KeyChar==(char)Keys.Space))
                    e.Handled = false;
                else
                    e.Handled = true;
            }
        }
    }

我应该使用&& oprator ???

should i use && oprator???

推荐答案

我应该使用&& oprator ???

否。

你不能取代||用和&& - 否则测试将始终失败，因为KeyChar值不能同时是Key.Back和Key.Space - 出于同样的原因，它不能同时是''X''和''7''时间！



在每个处理程序的开头放置一个断点，并按照它进行操作 - 看看当你按下空格键并尝试从那里开始工作时会发生什么。



BTW：不要这样写：

"should i use && oprator??? "
No.
You can''t replace the "||" with and "&&" - otherwise teh test will always fail as teh KeyChar value cannot both be Key.Back and Key.Space at the same time - for the same reason it can''t be ''X'' and ''7'' at the same time!

Put a breakpoint at the start of each handler, and follow it through - see what happens when you press the space bar and try to work it out from there.

BTW: Don''t write it like this:

if (char.IsNumber(e.KeyChar) == false)

不过，请使用：

INstead, use this:

if (!char.IsNumber(e.KeyChar))

一旦你习惯它，它会更紧凑，更明显！

It''s a lot more compact and more obvious once you get used to it!

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