如何在运行时将两个文本框的值乘以第三个文本框 [英] how to multiply value of two textboxs into the third text box at runtime

问题描述

如何在运行时将两个文本框的值乘以第三个文本框

推荐答案

将其命名为WinForms:例如，对于十进制值，请使用 Decimal.Parse方法 [^ ].例如:

Taken this is WinForms: For example with decimal values use Decimal.Parse Method[^]. For example:

textBox3.Text = (Decimal.Parse(textBox1.Text) * Decimal.Parse(textBox2.Text)).ToString();

当然，您需要添加检查，使用try catch，还可以使用TryParse等.

加法:
您可以将代码放在您喜欢的任何位置.例如，您可以使用文本框Validating event，KeyUp，KeyDown等可行的方法.

Of course you need to add checks, use try catch, possibly use TryParse instead and so on.

Addition:
You can put the code where anywhere you like. For example you can use the text boxes Validating event, KeyUp, KeyDown etc, whatever is feasible.

要执行此操作而无需回发，您应该使用javascript--

To do this without postback you should use javascript--

function updateValue()
{
  var val1=document.getElementByID("<%=textbox1.ClientID%>").value;
  var val2=document.getElementByID("<%=textbox2.ClientID%>").value;
  document.getElementByID("<%=textbox3.ClientID%>").value=parseFloat(val1)*parseFloat(val2);
}

现在，您可以在需要的任何javascript事件中调用此函数，而我会在blur--
处调用此函数
写在pageload上

now you can call this at any javascript event of your need i am calling this at blur-

write this on pageload

textbox1.Attribute.Add("onblur","updateValue()");
textbox2.Attribute.Add("onblur","updateValue()");

--Pankaj

--Pankaj

要在用户更改其他文本框时更新文本框，只需复制Mika提供的代码并将其粘贴到TextChanged事件处理程序中:

To update the textbox when the user changes the other ones, you just need to copy the code provided by Mika and paste it into a TextChanged event handler:

public YourForm()
{
   InitializeComponent();
   //add the handler for the two input boxes
   textBox1.TextChanged += textbox_TextChanged;
   textBox2.TextChanged += textbox_TextChanged;
}

private void textBox_TextChanged(object sender, EventArgs e)
{
   try
   {
       textBox3.Text = (Decimal.Parse(textBox1.Text) * Decimal.Parse(textBox2.Text)).ToString();
   }
   catch
   {
       //an error occured...
   }
}

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