Context context =getBaseContext(); 我在Activity类下面调用。为什么在onCreate方法里面再调用context就是空了？

Question

方法一 可以

public class DelCacheActivity extends MessageActivity {
    
    private static String Size = null;
    Context context;
    DelCacheManager dcm = new DelCacheManager();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	init("设置", "设置");	
	setContentView (R.layout.shezhi);
	context = getBaseContext();
	TextView textView = (TextView) this.findViewById(R.id.delcache);
	textView.setOnClickListener(new ButtonClickListener());
    }
}

方法二，方法二为什么不行？

public class DelCacheActivity extends MessageActivity {
    
    private static String Size = null;
    Context context = getBaseContext();;
    DelCacheManager dcm = new DelCacheManager();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	init("设置", "设置");	
	setContentView (R.layout.shezhi);
	
	TextView textView = (TextView) this.findViewById(R.id.delcache);
	textView.setOnClickListener(new ButtonClickListener());
    }
}

Context context =getBaseContext(); 我在Activity类下面调用。为什么在onCreate方法里面再调用context就是空了？

Answer 1

没人回复呢！

Answer 2

作用域生命周期的问题哈

Answer 3

onCreate函数里是创建Activity，context是Activity的上下文，没有创建Activity，哪来的context