Question

我只是一名学生开始学习C＃，所以如果我的问题不是很清楚，我会道歉。我被困在了答案中。我不知道如何编写ArgumentOutofRangeException代码，因此用户不会超出列表的边缘。我有两个，有两个索引变量。我也有updateControls的问题。任何帮助将不胜感激。

private void updateControls()
{
    pictureBox1.Image = resList[currentResIndex].Photo;
    lblName.Text = resList[currentResIndex].Title;
    lblCity.Text = resList[currentResIndex].City;
    lblPrice.Text = resList[currentResIndex].Price.ToString("C");

    pictureBox1.Image = comList[currentCommIndex].Photo;
    lblName.Text = comList[currentCommIndex].Title;
    lblCity.Text = comList[currentCommIndex].City;
    lblPrice.Text = comList[currentCommIndex].Price.ToString("C");
}

private void btnNext_Click(object sender, EventArgs e)
{
    if (cboType.SelectedItem.ToString() == "Residential") //if they chose residential then increment resIndex
        currentResIndex++;
      updateControls();
    else
      currentCommIndex++;//or else commIndex
   updateControls();
}

Answer 1

您可以在btnNext_Click方法中强制执行范围：

private void btnNext_Click(object sender, EventArgs e)
{
    if (cboType.SelectedItem.ToString() == "Residential")//if they chose residential then increment resIndex
        currentResIndex++;
    else
        currentCommIndex++;//or else commIndex

    currentCommIndex = Math.Min(comList.Length-1, currentCommIndex);
    currentResIndex = Math.Min(resList.Length-1, currentResIndex);
    updateControls();
}

Answer 2

  if (cboType.SelectedItem.ToString() == "Residential"
          && currentResIndex < resList.Count -1)    // add this condition
    currentResIndex++;

    updateControls();

Answer 3

try
{
    if (cboType.SelectedItem.ToString() == "Residential") //if they chose residential then increment resIndex  
    {       
        currentResIndex++;       
    }
    else      
    {    
        currentCommIndex++;//or else commIndex 
    }
    updateControls();
}
catch (ArgumentOutOfRangeException ex)
{
    //Do the things you want when this exception occurs
}

但你不应该使用这个。您应该检查是否到达列表的末尾。

ArgumentOutOfRangeException和updateControls方法

3 个答案: