如何从C＃中的形式返回一个值？ [英] How to return a value from a Form in C#?

问题描述

我有一个主表（让我们称之为frmHireQuote），这是一个主要的MDI窗体（frmMainMDI），这显示了另一种形式（frmImportContact）通过ShowDialog的（）单击一个按钮时，一个孩子

I have a main form (let's call it frmHireQuote) that is a child of a main MDI form (frmMainMDI), that shows another form (frmImportContact) via ShowDialog() when a button is clicked.

当用户点击frmImportContact'确定'，我想传递一些字符串变量找回一些文本框上frmHireQuote。

When the user clicks the 'OK' on frmImportContact, I want to pass a few string variables back to some text boxes on frmHireQuote.

请注意，有可能是frmHireQuote的多个实例，这显然是重要的，我回到那个叫frmImportContact这个实例的实例。

Note that there could be multiple instances of frmHireQuote, it's obviously important that I get back to the instance that called this instance of frmImportContact.

什么是这样做的最好方法是什么？

What's the best method of doing this?

推荐答案

在子表单创建一些公共属性像这样

public string ReturnValue1 {get;set;} 
public string ReturnValue2 {get;set;}

然后设置这里面您的分形式确定按钮单击处理程序

then set this inside your sub-form ok button click handler

private void btnOk_Click(object sender,EventArgs e)
{
    this.ReturnValue1 = "Something";
    this.ReturnValue2 = DateTime.Now.ToString(); //example
    this.Close();
}

然后在 frmHireQuote形式，当您打开子窗体

using (var form = new frmImportContact())
{
    var result = form.ShowDialog();
    if (result == DialogResult.OK)
    {
        string val = form.ReturnValue1;            //values preserved after close
        string dateString = form.ReturnValue2;
        //Do something here with these values

        //for example
        this.txtSomething.Text = val;
    }
}

Additionaly如果你想抵消分形式你可以添加一个按钮的形式，并设置其<一个href="http://msdn.microsoft.com/en-GB/library/system.windows.forms.button.dialogresult.aspx">DialogResult以取消，你还可以设置<一个href="http://msdn.microsoft.com/en-GB/library/system.windows.forms.form.cancelbutton%28v=vs.80%29.aspx">CancelButton表格的属性来表示按钮 - 这将使ESC键，取消表单的

Additionaly if you wish to cancel out of the sub-form you can just add a button to the form and set its DialogResult to Cancel and you can also set the CancelButton property of the form to said button - this will enable the escape key to cancel out of the form.

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