android to show alert dialog from non-UI or Non activity class

问题

Hi Android programmers,

This question is previously asked. But there is no answer. So i need solution for that. Actually i am trying to display alert box of Mainactivity.java calling from test.java(Non-activity).

Thats working fine if their is no UI coding. if that code is dependent with UI means its throw errors.

Activity class :

public class Mainactivity extends Activity
{
    public void message()
    {
        Log.i("Success : Call from non-UI & non activity class");//Upto this line working if i called message() function from other non-activity class
        DialogInterface.OnClickListener dialogClickListener = new DialogInterface.OnClickListener()
        {
        public void onClick(DialogInterface dialog, int which)
        {
             switch (which)
             {
                //Code
            }
         }
     };
     AlertDialog.Builder builder = new AlertDialog.Builder(this);
     builder.setTitle("FMS Status Message :- ");
     builder.setMessage(msg)
     .setPositiveButton("OK",dialogClickListener).show();

    }
}

Non-Activity class :

public class test extends BroadcastReceiver
{
    Mainactvity in = new Mainactvity();   

    @Override   
    public void onReceive(Context context, Intent intent)
    {
       in.message();
    }
}

If it is resolved then my main objective of my project will be completed. Please any one of you help me.

Thanks in advance.

回答1:

First of All, Bad Programming Practice for Android,

Mainactvity in = new Mainactvity();

You can not make a Constructor of Activity class.

And second, You are trying to display UI elements in Dialog which has not reference of Activity, in BroadcastReceiver. Use Context of Activity (If it concern with UI) or Application for displaying Dialog in BroadcastReceiver.

回答2:

Create a Constructor, where you can get Activity. Like this -

Activity activity;
public test (Activity activity){
         this.activity = activity;
}

Now, use this activity as argument -

AlertDialog.Builder adb=new AlertDialog.Builder(activity);

Because dialog can't be shown using just a context. You need to provide an Activity for that.

I answered one here

来源：https://stackoverflow.com/questions/14869284/android-to-show-alert-dialog-from-non-ui-or-non-activity-class

标签

java

android

android-dialog