为什么将currentView分配给错误的视图？

Question

我有一个称为“活动”的活动，当通过setContentView（）方法单击按钮时，该活动在View1和View2之间切换。

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.category_list);

    }

我想在按下设备上的BackButton时切换到View1。

public void onBackPressed(){
        View currentView = this.findViewById(R.layout.product_list);
        if(currentView == findViewById(R.layout.category_list)){
            Log.i("VIEW1", "BACKBUTTON CLICKED ON VIEW1");

        } else if(currentView == findViewById(R.layout.product_list)) {
            Log.i("VIEW2", "BACKBUTTON CLICKED ON VIEW2");
        }
    }

每当我单击view2上的后退按钮时，都会触发view1的if语句。当我将其分配给view2时，currentView变为view1。为什么会这样？

public void onClick(View view) {      

        setContentView(R.layout.product_list);          
    }

Answer 1

1. 在类级别声明View currentView

2. 在onCreate中设置值

   currentView = this.findViewById(R.layout.category_list);
   

3. 然后

   public void onBackPressed(){;
        if(currentView == findViewById(R.layout.category_list)){
             Log.i("VIEW1", "BACKBUTTON CLICKED ON VIEW1");
             currentView = this.findViewById(R.layout.product_list);
         } else {
             Log.i("VIEW2", "BACKBUTTON CLICKED ON VIEW2");
             currentView = this.findViewById(R.layout.category_list);
         }
    }
   

祝你好运