從類訪問表單控件？

Question

我的表單上有一個“ Get Status按鈕，當前的代碼如下所示：

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);
        }
    }
}
}

現在在Runner類中，我有：

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

我基本上想做的是讓btnGetStatus在Runner類中調用GetStatus方法，然后我想要該方法做的就是基本上檢查布爾值HasFinished以查看跑步者是否完成，是否已經完成， lblRunnerInfo.Text有一條消息可以反映這一點，如果布爾值是false，則基本上輸出一條消息，說“ Runner尚未完成/尚未完成”。

我不太確定從類訪問表單控件是否是正確的做法，或者甚至可以做到，但是我不確定如何按照自己的方式進行操作（獲取GetStatus方法以檢查控件的狀態）。運行程序，而不是讓btnGetStatus觸發代碼。）

Answer 1

我認為您正在尋找的是：

lblRunnerInfo.Text = selectedRunner.GetStatus();

然后在跑步類中：

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";
    }
}

這樣，表單處理輸出，而Runner類負責“運行”。 如果以后您的狀態狀況更為復雜，則仍然可以為狀態添加枚舉並檢索狀態，而不僅僅是檢查HasFinished。 要檢索文本，您需要添加一個從Status枚舉到適當文本的映射。

Answer 3

為什么不直接訪問HasFinished（）屬性呢？

    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

這樣的事情怎么樣

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);
    }

}

然后將您的GetStatus設置為字符串

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