Question

好吧，我想要一个在数据有效时可以单击的按钮，在数据无效时不能单击的按钮。该代码是正确的，可以运行而没有任何问题，但是我不知道该在何时触发该代码？过去，我将此代码放在“受保护的重写无效WndProc”中，但是我在视觉上遇到了一些小故障，无法保存在其中。

if (FirstName.Text == null || LastName.Text == null || Email.Text == null || Password.Text == null || Password2.Text == null || Password.Text != Password2.Text || LastName.Text == "Last Name" && FirstName.Text == "First Name" && Email.Text == "Email")
            {
                RegisterDone.Text = " You missed something";
                RegisterDone.Normalcolor = Color.FromArgb(64, 64, 64);
                RegisterDone.OnHovercolor = Color.FromArgb(64, 64, 64);
                RegisterDone.Activecolor = Color.FromArgb(64, 64, 64);
                RegisterDone.Textcolor = Color.FromArgb(197, 161, 89);
                RegisterDone.OnHoverTextColor = Color.FromArgb(197, 161, 89);
                RegisterDone.Cursor = Cursors.No;
                RegisterDone.Iconimage = Image.FromFile(@"C:\Users\gamin\Desktop\Icons\Forbidden.png");
            }
if (FirstName.Text != null && LastName.Text != null && Email.Text != null && Password.Text == Password2.Text && LastName.Text != "Last Name" && FirstName.Text != "First Name" && Email.Text != "Email")
            {
                RegisterDone.Text = "    Register right now";
                RegisterDone.Normalcolor = Color.FromArgb(4, 41, 50);
                RegisterDone.OnHovercolor = Color.FromArgb(4, 41, 50);
                RegisterDone.Activecolor = Color.FromArgb(4, 41, 50);
                RegisterDone.Textcolor = Color.FromArgb(197, 161, 89);
                RegisterDone.OnHoverTextColor = Color.FromArgb(197, 161, 89);
                RegisterDone.Cursor = Cursors.Hand;
                RegisterDone.Iconimage = Image.FromFile(@"C:\Users\gamin\Desktop\Icons\Valid.png");
            }

Answer 1

您应该将此代码放在FormLoad上：

FirstName.TextChanged += TextBox_TextChanged;
LastName.TextChanged += TextBox_TextChanged;
Email.TextChanged += TextBox_TextChanged;
Password.TextChanged += TextBox_TextChanged;
Password2.TextChanged += TextBox_TextChanged;

并将该代码在表单中的任何位置作为单独的函数进行编码：

private void TextBox_TextChanged(object sender, EventArgs e)
{
    if (FirstName.Text == null || LastName.Text == null || Email.Text == null || Password.Text == null || Password2.Text == null || Password.Text != Password2.Text || LastName.Text == "Last Name" && FirstName.Text == "First Name" && Email.Text == "Email")
            {
                RegisterDone.Text = " You missed something";
                RegisterDone.Normalcolor = Color.FromArgb(64, 64, 64);
                RegisterDone.OnHovercolor = Color.FromArgb(64, 64, 64);
                RegisterDone.Activecolor = Color.FromArgb(64, 64, 64);
                RegisterDone.Textcolor = Color.FromArgb(197, 161, 89);
                RegisterDone.OnHoverTextColor = Color.FromArgb(197, 161, 89);
                RegisterDone.Cursor = Cursors.No;
                RegisterDone.Iconimage = Image.FromFile(@"C:\Users\gamin\Desktop\Icons\Forbidden.png");
            }
    if (FirstName.Text != null && LastName.Text != null && Email.Text != null && Password.Text == Password2.Text && LastName.Text != "Last Name" && FirstName.Text != "First Name" && Email.Text != "Email")
            {
                RegisterDone.Text = "    Register right now";
                RegisterDone.Normalcolor = Color.FromArgb(4, 41, 50);
                RegisterDone.OnHovercolor = Color.FromArgb(4, 41, 50);
                RegisterDone.Activecolor = Color.FromArgb(4, 41, 50);
                RegisterDone.Textcolor = Color.FromArgb(197, 161, 89);
                RegisterDone.OnHoverTextColor = Color.FromArgb(197, 161, 89);
                RegisterDone.Cursor = Cursors.Hand;
                RegisterDone.Iconimage = Image.FromFile(@"C:\Users\gamin\Desktop\Icons\Valid.png");
            }
}

另一件事是您说您的代码有效，但是我不确定任何textbox.Text可以为null。也许您需要将其更改为

textbox.Text == "";

或者如果您仍然想防止使用null：

string.IsNullOrWhiteSpace(textbox.Text);

Answer 2

//向要检查的所有文本框注册事件

LastName.TextChanged += new EventHandler(textbox_TextChanged); FirstName.TextChanged += new EventHandler(textbox_TextChanged); private void textbox_TextChanged(object sender, EventArgs e) { //call your validation code here. }

如果要“丢失焦点”，“ KeyUp”等，可以使用其他事件。

我应该将这些代码随时放在哪里？

2 个答案: