设置 TypeFace NullpointerException

Question

我想在我的 TextView 中添加一个 TypeFace。这是我的 Java 代码

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        TextView helptitle = (TextView)findViewById(R.id.title_help);
        Typeface typeface = Typeface.createFromAsset(getAssets(), "beyond_the_mountains.ttf");
        helptitle.setTypeface(typeface);
        setContentView(R.layout.activity_help);
}

但是当我运行应用程序时，我收到一个 log cat 错误

Caused by: java.lang.NullPointerException
    at com.example.enxin.crystallise.Help.onCreate(Help.java:15)

NullPointerException 有很多种，不知道怎么解决

Answer 1

 //You have mistaken the order
 setContentView(R.layout.activity_help);    
 TextView helptitle = (TextView)findViewById(R.id.title_help);
 Typeface typeface = Typeface.createFromAsset(getAssets(),    "beyond_the_mountains.ttf");
 helptitle.setTypeface(typeface);

Answer 2

问题是您在设置内容视图之前调用 findViewById()。

findViewById() 隐含地调用了 getWindow()，此时它仍然是 null。

在初始化您的 View:

之前调用 setContentView()
@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_help); TextView helptitle = (TextView)findViewById(R.id.title_help); Typeface typeface = Typeface.createFromAsset(getAssets(), "beyond_the_mountains.ttf"); helptitle.setTypeface(typeface); }

设置 TypeFace NullpointerException

Setting TypeFace NullpointerException

android

typeface