setContentView来自另一个类的多个活动

Question

I am creating a android application which needs to be able to setcontentview on multiple android activities layouts in few methods in a another global class. Therefore when I call the method from a new activity onCreate then the buttons and textviews are assigned by findviewbyId by method in previously defined class. Example code is shown below.

   public void executeWorkItem() {
            setContentView(R.layout.activity_message);
            Button button = (Button) findViewById(R.id.btnSendSMS);
            button.setOnClickListener(new Button.OnClickListener() {
                public void onClick(View v) {
                    EditText textPhone = (EditText) findViewById(R.id.phoneNum);
                    EditText textSms = (EditText) findViewById(R.id.smsContent);
                    final String phoneNumber = textPhone.getText().toString();
                    final String message = textSms.getText().toString();
                    Map<String, Object> results = new HashMap<String, Object>();
                    results.put("phoneNmbr", "" + phoneNumber);
                    results.put("message", "" + message);
                }
            });
        }

Therefore when I call this method from activity like shown below then the methhod should be executed without getting null error.

  @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    app = (MyApplication)getApplication();

     // Call a custom application method
    app.executeWorkItem();
} 

Therefore should I create a application class for this or do I have to create a Object which extends Activity and call that object method in there ? Note : that I should be able to create different methods which can do similar things.

Answer 1

Very easy to do. All you need is a Parent Activity like a BaseActivity, then all the other activities simple extend that Parent Activity, like so:

public class BaseActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_message);
        Button button = (Button) findViewById(R.id.btnSendSMS);
        button.setOnClickListener(new Button.OnClickListener() {
            public void onClick(View v) {
                EditText textPhone = (EditText) findViewById(R.id.phoneNum);
                EditText textSms = (EditText) findViewById(R.id.smsContent);
                final String phoneNumber = textPhone.getText().toString();
                final String message = textSms.getText().toString();
                Map<String, Object> results = new HashMap<String, Object>();
                results.put("phoneNmbr", "" + phoneNumber);
                results.put("message", "" + message);
            }
        });
    }
}

Then all your other activities extend the Parent Activity like so:

public class MainActivity extends BaseActivity {
@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //Do not call setContentView again
    }
}

public class SecondActivity extends BaseActivity {
@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //Do not call setContentView again
    }
}

If you notice the super.onCreate(savedInstanceState) It is simply calling the onCreate method of it's parent class, in this case BaseActivity (which in turn calls Activity class).

Answer 2

Not sure I am getting your question fully correct, but perhaps you should create base class for your activities that would wire all common listeners and other things on its onCreate() . Your layouts should contain all the buttons base class expects to find (most likely you may want to use <include> or <merge> ( see docs ). Alternatively you can consider using Fragments but that may be more work for you to do.

PS: I do not know what app.executeWorkItem(); is doing but are you sure application class is the right place for it?

EDIT

I am not sure about that. I want to handle multiple layouts of multiple activities from single class / activity

This is only matter of how you pass the layoutId to be used. You can make base class abstract with method like abstract int getLayoutId()) and then your base's onCreate() would only need to do setContentView(getLayoutId()); or you can drop base's onCreate() and instead override setContentView()) and do your wiring there (but I do not like that really).