Question

我正在使用c＃winforms。当我单击按钮时，程序会显示列表中的2个单词，但有时单词会重复。我怎么做不要让重复的话

这是代码

private void button1_Click(object sender, EventArgs e)
{
    var words = new[] { "Worm", "Fast", "Death", "boat", "Sneak", "Destroction" };
    var wordsInRandomOrder = words.OrderBy(i => Guid.NewGuid());

    foreach (var word in wordsInRandomOrder)
    {
        textBox1.Text = word;
        break;
    }

    foreach (var word in wordsInRandomOrder)
    {
        textBox1.Text = textBox1.Text + " " + word;
        break;
    }
}

Answer 1

选项1：

private void button1_Click(object sender, EventArgs e)
{
    var words = new[] { "Worm", "Fast", "Death", "boat", "Sneak", "Destroction" };
    var wordsInRandomOrder = words.OrderBy(i => Guid.NewGuid()).ToList();
    textBox1.Text = wordsInRandomOrder[0] + " " + wordsInRandomOrder[1];
}

选项2：

var words = new[] { "Worm", "Fast", "Death", "boat", "Sneak", "Destroction" };
Random rd = new Random();

int firstIndex = rd.Next(0, words.Length);
int secondIndex = rd.Next(0, words.Length);

while (secondIndex == firstIndex)
{
    secondIndex = rd.Next(0, words.Length);
}

textBox1.Text = words[firstIndex] + " " + words[secondIndex];

Answer 2

Random rd = new Random();

int firstIndex = rd.Next(0, words.Length);
int secondIndex = rd.Next(0, words.Length);

while (secondIndex == firstIndex)
{
    secondIndex = rd.Next(0, words.Length);
}

textBox1.Text = words[firstIndex] + " " + words[secondIndex];

Answer 3

不使用Guid的类似方法：

private void button1_Click(object sender, EventArgs e)
{
    Random r = new Random();
    var words = new[] { "Worm", "Fast", "Death", "boat", "Sneak", "Destroction" };
    var wordsInRandomOrder = words.OrderBy(i => r.Next()).ToList();

    textBox1.Text = String.Join(" ", wordsInRandomOrder.Take(2));
}

使用此appraoch甚至如果，随机发生器两次生成相同的数字（这是相当不可能的），您可以从列表中选择另一个单词，因为它们只是按顺序排序。如果两个商品具有相同的订单价值，则可以任意订购，但同一商品不会被使用两次。

Answer 4

如果 realllllly 希望保留您正在使用的代码，请在第二个foreach中执行以下操作：

foreach (var word in wordsInRandomOrder)
{
    if(word != textBox1.Text)
    {
       textBox1.Text = textBox1.Text + " " + word;
       break;
    }
}

但是更好的选择就像juharr写的那样：

textBox1.Text = string.Join(" ", wordsInRandomOrder.Take(2));

如果你想要循环的路线，加入可能会更好两个＆＃34; foreach es＆＃34;你喜欢这样：

foreach (string word in wordsInRandomOrder)
{
    if(textBox1.Text = "")
    {
        textBox1.Text = word;
    }
    else
    {
        if(textBox1.Text != word)
        {
            textBox1.Text = textBox1.Text + " " + word;
            break;
        }
    }
}

不要重复一些名字

4 个答案: