java - 不能为字段分配内存吗？

Question

我是 Java 新手。我在包含myImageViews[0].v1 = new ImageView(context). 有什么问题吗？

class MyImageViews
{
    ImageView v1;
    ImageView v2;
}

MyImageViews[] myImageViews;

protected class MyLayout extends RelativeLayout {
    public MyLayout(Context context) {
        super(context);
        myImageViews = new MyImageViews[10];
        myImageViews[0].v1 = new ImageView(context); //runtime error at this line   
    }   
}

Answer 1

MyImageViews您已经创建了一个可以包含实例但尚未创建实例 的数组。myImageViews[0]一片空白。

尝试改变

myImageViews = new MyImageViews[10];

至

myImageViews = new MyImageViews[10];
for (int i = myImageViews.length; --i >= 0;) {
  myImageViews[i] = new MyImageViews();
}

Answer 2

你要

 myImageViews[0] = new MyImageViews(); 
 myImageViews[0].v1 = new ImageView(context);