如何从自定义 FirebaseListAdapter class 调用 mainActivity 中的静态方法？

Question

我想使用 Firebase 在 ChatListAdapter class 的 mainActivity 中弹出一个警报视图。

Problem/Error:

com.firebase.androidchat.Main.activity.this cannot be reference from a static context

ChatListAdapter 中的代码：

public class ChatListAdapter extends FirebaseListAdapter<Chat> {

...

protected void populateView(View view, Chat chat) {
...    
    MainActivity.displayAmountPopup();
}

ChatListAdapter 中的代码：

public static void displayAmountPopup(){

....

    new AlertDialog.Builder(MainActivity.this)
            .setTitle(strTitle)
            .setMessage(strAmountMessage)
            .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    Log.d("AlertDialog", "Positive");
                    // Present Acknowledgement View!!!!!!!!!
                    Intent intent = new Intent(MainActivity.this, AcknowledgementActivity.class);
                    startActivity(intent);

                    /*Couldn't work this Error:local variable mContext is accessed from within inner class; needs to be declared final
                    Intent intent = new Intent(mContext, AcknowledgementActivity.class);
                    //startActivity(intent);
                    mContext.startActivity(new Intent(mContext, AcknowledgementActivity.class));*/
                }
            })
            .setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    Log.d("AlertDialog", "Negative");
                }
            })
            .show();
}

Answer 1

com.firebase.androidchat.Main.activity.this cannot be reference from a static context

因为无法从 static method/block.

访问 MainActivity.this

要获取用于显示 AlertDialog 的上下文，请将一个上下文参数添加到 displayAmountPopup 方法：

public static void displayAmountPopup(Context mContext){
....
    new AlertDialog.Builder(mContext)
    ....
}

现在从 populateView 调用时将上下文传递给 displayAmountPopup 方法：

MainActivity.displayAmountPopup(view.getContext());

Answer 2

您可以在对话框中使用上下文并施放 activity 以启动 Intent

Intent intent = new Intent(context, AcknowledgementActivity.class);
((Activity) context).startActivity(intent)

来自注释代码

public static void displayAmountPopup(Context context){

....

    new AlertDialog.Builder(context)
            .setTitle(strTitle)
            .setMessage(strAmountMessage)
            .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    Log.d("AlertDialog", "Positive");
                    // Present Acknowledgement View
                    //Intent intent = new Intent(context, AcknowledgementActivity.class);
                    //startActivity(intent);
                }
            })
            .setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    Log.d("AlertDialog", "Negative");
                }
            })
            .show();
}

如何从自定义 FirebaseListAdapter class 调用 mainActivity 中的静态方法？

How to call a static method in mainActivity from a custom FirebaseListAdapter class?

android

firebase