更改按钮文本-Windows Phone 7

Question

How do you change the text of a button in Windows Phone 7 and C#? NullPointer Exception too, if I am doing the changing of the button text right, what is the problem?

public void CreateWords(Word[] theWords)
{
    listOfWords = new Button[theWords.Length]; //Button Array
    textBlock1.Text = theWords[0].getWord(); //Totally Works
    for (int i = 0; i < theWords.Length; i++)
    {
        listOfWords[i].Content = theWords[0].getWord(); //NullPointer Exception
    }

    for (int i = 0; i < theWords.Length; i++)
    {
        stackWords.Children.Add(listOfWords[i]);
    }
}

Answer 1

之所以得到NullReferenceException是因为在创建新的Button数组时，尚未初始化该数组的任何元素（每个元素仍为null）。

Answer 2

As Justin said earlier, you have just created an Array of the Type of Button, You have not added any Button's to the Array as of yet. You need to explicitly set each index of the Array to a Button: Try doing something like this.

for (int i = 0; i < theWords.Length; i++) 
{ 
    listOfWords[i] = new Button();
    listOfWords[i].Content = theWords[0].getWord(); //NullPointer Exception 
}