创建SpannableString时抛出NullPointerException

Question

我正在尝试创建一个textview，其文本使用spannableString部分加下划线，但是当我尝试这样做时，我得到了一个nullpointerexception。这是我的代码：

tv = (TextView) findViewById(R.id.tvHelp);
    SpannableString content = new SpannableString("Underlined text");
    content.setSpan(new UnderlineSpan(), 0, content.length(), 0);
    tv.setText(content+"non-underlined text"); //exception is thrown here
    super.onCreate(savedInstanceState);

提前感谢您的帮助。

Answer 1

tv = (TextView) findViewById(R.id.tvHelp);
SpannableString content = new SpannableString("Underlined text");
content.setSpan(new UnderlineSpan(), 0, content.length(), 0);
tv.setText(content+"non-underlined text"); //exception is thrown here

在

之后写上面的代码

super.onCreate(savedInstanceState);
and
setContentView("Your Layout");