从类访问表单控件？

Question

我的表单上有一个“ Get Status按钮，当前的代码如下所示：

private void btnGetStatus_Click(object sender, EventArgs e)
    {
        // Check if a runner has been selected
        if (lstRunners.SelectedIndex > -1)
        {
            // Obtain selected runner
            Runner selectedRunner = (Runner)lstRunners.SelectedItem;

            // Call the method in Runner class to get the runner's status
            selectedRunner.GetStatus(selectedRunner);
        }
    }
}
}

现在在Runner类中，我有：

public void GetStatus(Runner selectedRunner)
    {
        if (selectedRunner.HasFinished == true)
        {
            lblRunnerInfo.Text = "Runner has already finished!";
        }
    }

我基本上想做的是让btnGetStatus在Runner类中调用GetStatus方法，然后我想要该方法做的就是基本上检查布尔值HasFinished以查看跑步者是否完成，是否已经完成， lblRunnerInfo.Text有一条消息可以反映这一点，如果布尔值是false，则基本上输出一条消息，说“ Runner尚未完成/尚未完成”。

我不太确定从类访问表单控件是否是正确的做法，或者甚至可以做到，但是我不确定如何按照自己的方式进行操作（获取GetStatus方法以检查控件的状态）。运行程序，而不是让btnGetStatus触发代码。）

Answer 1

我认为您正在寻找的是：

lblRunnerInfo.Text = selectedRunner.GetStatus();

然后在跑步类中：

public string GetStatus()
{
    if (this.HasFinished == true)
    {
        return "Runner has already finished!";
    }
    return "Finished";
}

Answer 2

您可以如下更改btnGetStatus_Click：

private void btnGetStatus_Click(object sender, EventArgs e)
{
    // Check if a runner has been selected
    if (lstRunners.SelectedIndex > -1)
    {
        // Obtain selected runner
        Runner selectedRunner = (Runner)lstRunners.SelectedItem;
        // Call the method in Runner class to get the runner's Status
        // CHANGED
        if (selectedRunner.HasFinished)
            lblRunnerInfo.Text = "Runner has already finished";
    }
}

这样，表单处理输出，而Runner类负责“运行”。 如果以后您的状态状况更为复杂，则仍然可以为状态添加枚举并检索状态，而不仅仅是检查HasFinished。 要检索文本，您需要添加一个从Status枚举到适当文本的映射。

Answer 3

为什么不直接访问HasFinished（）属性呢？

    private void btnGetStatus_Click(object sender, EventArgs e)
    {
        // Check if a runner has been selected
        if (lstRunners.SelectedIndex > -1)
        {
            // Obtain selected runner
            Runner selectedRunner = (Runner)lstRunners.SelectedItem;

            // Call the method in Runner class to get the runner's status
            if (selectedRunner.HasFinished)
            {
                lblRunnerInfo.Text = "Runner has already finished!";
            }
            else
            {
                lblRunnerInfo.Text = "Runner has NOT finished yet!";
            }
        }
    }

Answer 4

这样的事情怎么样

private void btnGetStatus_Click(object sender, EventArgs e)
{
    // Check if a runner has been selected
    if (lstRunners.SelectedIndex > -1)
    {
        // Obtain selected runner
        Runner selectedRunner = (Runner)lstRunners.SelectedItem;

        // Call the method in Runner class to get the runner's status
        lblRunnerInfo.Text = selectedRunner.GetStatus(selectedRunner);
    }

}

然后将您的GetStatus设置为字符串

public string GetStatus(Runner selectedRunner)
{
    if (selectedRunner.HasFinished == true)
    {
        return "Runner has already finished!";
    }
}