如何使用if else构造 [英] How to use if else construct

问题描述

你好，我想在表单/按钮上使用if else构造.在这种情况下，在我有一个文本框，保存按钮和开始按钮的表单上，保存按钮保存了通过文本框提供的用户输入，现在当用户单击开始按钮时，该按钮将打开另一个表单.我希望使用开始"按钮来确保用户单击了保存"按钮.
代码示例会有所帮助....

在此先感谢

hello, i want to use the if else construct on forms/buttons. here is the situation, on a form i have a textbox,save button and start button, the save button saves user input that has been provided through the textbox, now when the user clicks the start button,the button opens another form. i want the start button to make sure that the user has clicked the save button.
code samples would help....

thanks in advance

推荐答案

让我们使用两个按钮cmdSave和cmdStart(用于保存"和开始"按钮).

我会有一个类级别的布尔标志(让我们称之为标志).

在cmdSave click方法上，我将此标志设置为true.

Lets take two buttons cmdSave and cmdStart (for the Save and Start buttons).

I would have a class level boolean flag (lets call it flag).

On the cmdSave click method, I would set this flag to true.

public void OncmdSaveClick(object sender, EventArgs e)
{
flag = true;
}

每当单击cmdStart按钮时，我都会检查该标志.只有设置了此标志(之前已单击保存"按钮，我才能运行该表单).如果没有，我将退出该方法.

Whenever the cmdStart button is clicked I would check for this flag. Only if this flag is set (the Save button had been clicked earlier, I would run the form). If not, I would just step out of the method.

public void OncmdStartClick(object sender, EventArgs e)
{
   //Call the new form if the flag is set
   if (flag)
    {
      CallNewForm(); //Calling the new form
    }
}

这样，您将确保至少单击一次保存"按钮.

This way, you will be sure the Save button has been clicked at least once.

从我收集的信息中:
-在表单加载中，将表单级别变量isSaved设置为false:

From what I gathered:
- in your form load, set a form level variable isSaved to false:

private bool isSaved = false;

-在保存"按钮中单击处理程序，更改变量的状态:

- in the save button click handler, change the state of the variable:

isSaved = true;

-在开始"按钮单击处理程序中，检查isSaved 是true:

- in the start button click handler, check that isSaved is true:

if (!isSaved) [
   System.Windows.MessageBox.Show("Save first or something");
   return;
}
// do the actual start code...

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