java - 如何从 fragment 设置 Activity 中按钮的边框

Question

我有这个方法:

public void ButtonBorder(Button button1, Button button2, Button button3, Button button4) {
    button1.setBackgroundResource(R.color.Transparent);
    button2.setBackgroundResource(R.drawable.bottom_btn_border);
    button3.setBackgroundResource(R.drawable.all_border);
    button4.setBackgroundResource(R.drawable.all_border);
}

我在我的 fragment onItemClick() 方法中调用它，如下所示:

@Override
public void onItemClick(int position) {

    Button button1= ((MainActivity)getActivity()).button1
    Button button2= ((MainActivity)getActivity()).button2;
    Button button3= ((MainActivity)getActivity()).button3;
    Button button4=((MainActivity)getActivity()).button4;

    ((MainActivity)getActivity()).ButtonBorder(button1, button2, button3, button4);
}

而且根本不起作用。
这是正确的做法吗？

Answer 1

您可以通过以下方法接收按钮变量

//In fragment
lateint var button : Button;

override fun onAttach(context: Context) {
    super.onAttach(context)
    button = context.getButton();

}



// In Activity    
var button = findViewById(R.id.your_button)
getButton(button)

//outside onCreateMethod

fun getButton(var button : Button) : Button
{
  return button
}