将数据从一个按钮单击事件传递到另一个按钮单击事件

Question

以下是我的代码。我想在两个不同的按钮点击中捕获两个时间戳之间的差异，即，我想要在btnEndTime_click事件中使用btnStartTime_click事件的“startTime”。

protected void btnStartTime_Click(object sender, EventArgs e) 
    { 
     var startTime = DateTime.Now;    
     lblStartTime.Text = startTime.ToString("HH:mm:ss tt");    
    } 

    protected void btnEndTime_Click(object sender, EventArgs e) 
    {    
     var workDuration = DateTime.Now.Subtract(startTime).TotalMinutes; 
     lblEndTime.Text = ("The Work duration is "+workDuration); 

    } 

Answer 1

因为这涉及到一个web应用程序，您必须在startTime存储在它可以在以后的文章中恢复回来的方式。

这里有一个快速的样品应工作使用ViewState：

private const string StartTimeViewstateKey = "StartTimeViewstateKey"; 
protected void btnStartTime_Click(object sender, EventArgs e) 
{ 
    var startTime = DateTime.Now; 
    ViewState[StartTimeViewstateKey] = startTime.ToString(CultureInfo.InvariantCulture); 
} 
protected void btnEndTime_Click(object sender, EventArgs e) 
{ 
    var startTime = DateTime.Parse((string)ViewState[StartTimeViewstateKey], CultureInfo.InvariantCulture); 

    var workDuration = DateTime.Now.Subtract(startTime).TotalMinutes; 
    lblEndTime.Text = ("The Work duration is " + workDuration); 
} 

另外，您可以使用会话状态：

private const string StartTimeSessionKey= "StartTimeSessionKey"; 
protected void btnStartTime_Click(object sender, EventArgs e) 
{ 
    var startTime = DateTime.Now; 
    Session[StartTimeSessionKey] = startTime; 
} 
protected void btnEndTime_Click(object sender, EventArgs e) 
{ 
    var startTime = (DateTime)Session[StartTimeSessionKey]; 

    var workDuration = DateTime.Now.Subtract(startTime).TotalMinutes; 
    lblEndTime.Text = ("The Work duration is " + workDuration); 
} 

Answer 2

只是让你startTime外的局部范围：

DateTime startTime; 
protected void btnStartTime_Click(object sender, EventArgs e) 
{ 
    startTime = DateTime.Now;    
    lblStartTime.Text = startTime.ToString("HH:mm:ss tt");    
} 

protected void btnEndTime_Click(object sender, EventArgs e) 
{    
    var workDuration = DateTime.Now.Subtract(startTime).TotalMinutes; 
    lblEndTime.Text = ("The Work duration is "+workDuration); 

}