使用上下文调用另一个类的方法 [英] Calling method of another class using contexts

问题描述

我有一个带有ImageButton的自定义标题栏，该标题栏生成一个对话框，并且当从对话框中选择列表项时，我希望能够在地图上(在另一个类中)显示位置(将itemizedOverlay放置)，标题栏和地图是在相同的上下文中.我在某处读到可以使用上下文调用另一个类的方法的地方.我该怎么办?

I have a custom titlebar with an ImageButton, which produces a dialogbox, and I want to be able to show location(place itemizedOverlay) on a map(in another class) when list item is selected from dialog box, and titlebar and map are in the same context. I read somewhere that I could call a method of another class using contexts. How can I do so?

public class MyTitleBar extends RelativeLayout{

private Context context;


public MyTitleBar(Context context, AttributeSet attrs) {
    super(context, attrs);
    this.context = context;
}

@Override
protected void onFinishInflate() {

    super.onFinishInflate();

    initViews();
}

// set up all the buttons  & clicks
private void initViews() {

    final ImageButton listImgBtn = (ImageButton) findViewById(R.id.more);
    final CharSequence [] listItems = {"Elderly","Events"};

    listImgBtn.setOnClickListener(new  View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if(context instanceof UserHome)
            {
                AlertDialog.Builder builder = new AlertDialog.Builder(context);
                builder.setTitle("List");
                builder.setItems(listItems, new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int item) {
                    // TODO Auto-generated method stub
                    if(item == 0)
                    {
                        //show location of elderly
                       //DisplayLocation()

                    }
                    else if(item == 1)
                    {
                        //show location of events
                    }
                }
            });
            AlertDialog alert = builder.create();
            alert.show();
          }
        }
    });

推荐答案

看来我可以这样做:

UserHome userhome = (UserHome)context;
userhome.DisplayLocation();

UserHome活动中的DisplayLocation().很简单.

where DisplayLocation() in the UserHome Activity. Simple.

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