C＃随机数生成器

Question

I'm using the following code to generate 4 random numbers, but each time I try to get the they're coming up as "system.random" in the textblock. Help anyone? Thanks!! :)

private void Button_Click_1(object sender, RoutedEventArgs e)        
{           
    Random dc1 = new Random();
    int dealCard1 = dc1.Next(52);

    Random dc2 = new Random();
    int dealCard2 = dc2.Next(52);

    Random pc1 = new Random();
    int playerCard1 = pc1.Next(52);

    Random pc2 = new Random();
    int playerCard2 = pc2.Next(52);

    txtDC1.Text = Convert.ToString(dc1);
    txtDC2.Text = Convert.ToString(dc2);
    txtPC1.Text = Convert.ToString(pc1);
    txtPC2.Text = Convert.ToString(pc2);
}

Answer 1

First off, you only need one random instance:

Random dc1 = new Random();
int dealCard1 = dc1.Next(52);
int dealCard2 = dc1.Next(52);
int playerCard1 = dc1.Next(52);
int playerCard2 = dc1.Next(52);

The errors are because you're not reporting the numbers:

txtDC1.Text = Convert.ToString(dealCard1);
txtDC2.Text = Convert.ToString(dealCard2);
txtPC1.Text = Convert.ToString(playerCard1);
txtPC2.Text = Convert.ToString(playerCard2);

Answer 2

You are converting the random number generator, not the random number.

Your random number generators are dc2 , pc1 , and pc2 . Your random numbers are dealCard2 , playerCard1 , and playerCard2 .

From here you should be able to solve the problem.

Answer 3

Taking just one for simplicity:

Random dc1 = new Random();
int dealCard1 = dc1.Next(52);
txtDC1.Text = Convert.ToString(dc1);

Here you've converted dc1 , which is a Random object to a string, not dealCard1 , which is the random number.

txtDC1.Text = Convert.ToString(dealCard1);

And so on.

(Note also, if the idea here is to pick for out of 52 cards, as with a playing card deck, that you aren't checking you don't have more than one of the exact same card, which may or may not be a problem).

Answer 4

You are putting the Random object itself into the textblock, hence "System.Random".

Your code should be:

txtDC1.Text = Convert.ToString(dealCard1);
txtDC2.Text = Convert.ToString(dealCard2);
txtPC1.Text = Convert.ToString(playerCard1);
txtPC2.Text = Convert.ToString(playerCard2);

You also shouldn't recreate the Random instance each time. Just use one (ideally as a class level variable). This prevents re-seeding the Random object with (nearly) the same seed value (which is based on the system time). As is, each of your "random" numbers could very well be identical!

Answer 5

First of all you're converting the wrong variable, what you want is

txtDC1.Text = Convert.ToString(dealCard1);
txtDC2.Text = Convert.ToString(dealCard2);
txtPC1.Text = Convert.ToString(playerCard1);
txtPC2.Text = Convert.ToString(playerCard2);

Also try to avoid creating a new instance of random every time you call the click event. Consider creating one random instance that can be reused.

If you must create a new instance at every event, then consider adding a seed to the random, as quick succession of events may cause the Random instance to be seeded with the same seed and thus causing repeated values.

Answer 6

I had trouble with this before and the error that I had was that I had too many random instance. So by looking at your code I see you got more than one. I would alter the coding to have only one random instance.