新手求教

Question

我按照书上打了这个代码，但一直运行不起来，不知道为什么？
public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        final String[] COLORS={
         "red","green","orange","blue","purple","black",
         "yellow","cycan","magenta"
         };
        ArrayAdapter<String> adapter=new ArrayAdapter<String>(this,
         android.R.layout.simple_dropdown_item_1line,
         COLORS);
        AutoCompleteTextView text=(AutoCompleteTextView) findViewById(R.id.autocompletetextview01);
        text.setAdapter(adapter);
       
        setContentView(R.layout.activity_main);
    }

Answer 1

这是错误信息：at com.kunge.helloworld.MainActivity.onCreate(MainActivity.java:24)

Answer 2

好像是 text.setAdapter(adapter);这里的adapter是个空指针。你看看应该怎么初始化adapter...

Answer 3

先获取布局setContentView(R.layout.activity_main);再find.

Answer 4

同意楼上的，setContentView 要放到find之前，要不怎么find的到呢。