C# C“数组”；圈；

我有一个数组：

class Words
{
   public static string[] wordsArray = { "one", "two", "three", "four" };
}

显示值数组的TextBlock和显示数组下一个值的按钮：

private int counter = 0;

    private void goButton_Click(object sender, RoutedEventArgs e)
    {

        if (counter < Words.wordsArray.Length)
        {
            enWordTextBlock.Text = Words.wordsArray[counter++];
        }
    }

private int counter=0；
私有无效按钮单击（对象发送器，路由目标）
{
if（计数器

当该框出现在数组的最后一个值上时，程序将继续不工作，如何使其在一个“圆圈”中工作

谢谢大家

这应该有效：

私有无效按钮单击（对象发送器，路由目标）
{
计数器+++；//增加计数器
int i=计数器%Words.wordsArray.Length；//模运算
enWordTextBlock.Text=Words.wordsArray[i]；//设置文本
}

[编辑]
好的，这是一个与user1397396注释相关的编辑。我不确定我是否理解正确，但你可能对负值模数有问题。例如：

int counter = 0;
int mod = 4;
counter--; // counter is -1 after this line is executed
int result = counter % mod; // result is -1
result = (counter + mod) % mod; // result is now 3 as desired

下面是我将如何实现这些下一个和上一个按钮

private int counter = 0;

private void NextButton_Click(object sender, RoutedEventArgs e)
{
    enWordTextBlock.Text = Words.wordsArray[counter % Words.wordsArray.Length];
    counter++; // put ++ operator in new line to avoid confusion
}

private void PreviousButton_Click(object sender, RoutedEventArgs e)
{
    int wordCount = Words.wordsArray.Length;
    // add wordCount before applying modulus (%) to avoid negative results
    // -1 % 5 = -1; -2 % 5 = -2; -6 % 5 = -1 etc
    // negative values would cause exception when accessing array
    counter = ((counter - 1) + wordCount) % wordCount; 
    enWordTextBlock.Text = Words.wordsArray[counter];
}

例如，此代码会导致按下Next、Previous、Next键，显示“一”、“四”、“一”。


更好的解决方案是使用如下方法（或内联代码）：

private static int GetPositiveIntModulus(int value, int mod)
{
    return ((value % mod) + mod) % mod;
}

对于任何值，它都会给您一个肯定的结果，即使

value<-mod

。所以你可以这样写上面的代码：

private int counter = 0;

private void NextButton_Click(object sender, RoutedEventArgs e)
{
    // uncomment this to ensure valid counter
    // if it is changed somewhere else in the program
    //counter = GetPositiveIntModulus(counter, Words.wordsArray.Length);
    enWordTextBlock.Text = Words.wordsArray[counter];
    counter = GetPositiveIntModulus(counter + 1, Words.wordsArray.Length);
}

private void PreviousButton_Click(object sender, RoutedEventArgs e)
{
    counter = GetPositiveIntModulus(counter - 1, Words.wordsArray.Length);
    enWordTextBlock.Text = Words.wordsArray[counter];
}

---

只是一个旁注：使用此代码，第一次单击按钮后的文本将为“2”，除非计数器初始化为-1。如果有两个按钮：NextButton和PreviousButton，当您单击NextButton时，您将看到数组中的下一个值；当您单击PreviousButton时-您将看到上一个值，但是如果第一个值显示数组，并且您单击PreviousButton-将是一个错误。如何在显示最后一个值时单击上一个按钮。“圈”正好相反？谢谢

private static int GetPositiveIntModulus(int value, int mod)
{
    return ((value % mod) + mod) % mod;
}

private int counter = 0;

private void NextButton_Click(object sender, RoutedEventArgs e)
{
    // uncomment this to ensure valid counter
    // if it is changed somewhere else in the program
    //counter = GetPositiveIntModulus(counter, Words.wordsArray.Length);
    enWordTextBlock.Text = Words.wordsArray[counter];
    counter = GetPositiveIntModulus(counter + 1, Words.wordsArray.Length);
}

private void PreviousButton_Click(object sender, RoutedEventArgs e)
{
    counter = GetPositiveIntModulus(counter - 1, Words.wordsArray.Length);
    enWordTextBlock.Text = Words.wordsArray[counter];
}