在Android中使用BaseActivity的不同活动中的Common Header

Question

I want write code once and use in different activities. I have created a Base Activity class for that . Also the header of all the layouts in different activities are same. I have done that with the help of the <include layout > tag.

Now the Problem is my BaseActivity code is not running. I am trying this first time se don't have much idea about that.

1.)The BaseActivity code is below :

package com.waheguru.app;

import android.R.integer;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;

import android.view.View;
import android.view.View.OnClickListener;

import android.widget.Button;
import android.widget.Toast;

public abstract class BaseActivityMenu extends Activity {
    //action id
    private static final int ID_UP     = 1;
    private static final int ID_DOWN   = 2;
    private static final int ID_SEARCH = 3;
    private static final int ID_INFO   = 4;
    private static final int ID_ERASE  = 5; 
    private static final int ID_OK     = 6;

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

        setContentView(R.layout.header);

        ActionItem nextItem     = new ActionItem(ID_DOWN, "Book", getResources().getDrawable(R.drawable.menu_down_arrow));
        ActionItem prevItem     = new ActionItem(ID_UP, "Bookmark", getResources().getDrawable(R.drawable.menu_up_arrow));
        ActionItem searchItem   = new ActionItem(ID_SEARCH, "Find", getResources().getDrawable(R.drawable.menu_search));
        ActionItem infoItem     = new ActionItem(ID_INFO, "Info", getResources().getDrawable(R.drawable.menu_info));
        ActionItem eraseItem    = new ActionItem(ID_ERASE, "Clear", getResources().getDrawable(R.drawable.menu_eraser));
        ActionItem okItem       = new ActionItem(ID_OK, "OK", getResources().getDrawable(R.drawable.menu_ok));

        //use setSticky(true) to disable QuickAction dialog being dismissed after an item is clicked
        prevItem.setSticky(true);
        nextItem.setSticky(true);

        //create QuickAction. Use QuickAction.VERTICAL or QuickAction.HORIZONTAL param to define layout 
        //orientation
        final QuickAction quickAction = new QuickAction(this, QuickAction.VERTICAL);

        //add action items into QuickAction
        quickAction.addActionItem(nextItem);
        quickAction.addActionItem(prevItem);
        quickAction.addActionItem(searchItem);
        quickAction.addActionItem(infoItem);
        quickAction.addActionItem(eraseItem);
        quickAction.addActionItem(okItem);

        //Set listener for action item clicked
        quickAction.setOnActionItemClickListener(new QuickAction.OnActionItemClickListener() {          
            public void onItemClick(QuickAction source, int pos, int actionId) {                
                ActionItem actionItem = quickAction.getActionItem(pos);

                //here we can filter which action item was clicked with pos or actionId parameter
                if (actionId == ID_SEARCH) {
                    Toast.makeText(getApplicationContext(), "Let's do some search action", Toast.LENGTH_SHORT).show();
                } else if (actionId == ID_INFO) {
                    Toast.makeText(getApplicationContext(), "I have no info this time", Toast.LENGTH_SHORT).show();
                } else {
                    Toast.makeText(getApplicationContext(), actionItem.getTitle() + " selected", Toast.LENGTH_SHORT).show();
                }
            }
        });

        //set listnener for on dismiss event, this listener will be called only if QuickAction dialog was dismissed
        //by clicking the area outside the dialog.
        quickAction.setOnDismissListener(new QuickAction.OnDismissListener() {          
            public void onDismiss() {
                Toast.makeText(getApplicationContext(), "Dismissed", Toast.LENGTH_SHORT).show();
            }
        });
        Button books=(Button)findViewById(R.id.book);
        books.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                Intent intent=new Intent(ExampleActivity.this,List_of_books.class);
                startActivityForResult(intent, 0);
            }
        });
        //show on btn1
        Button btn1 = (Button) this.findViewById(R.id.menu);
        btn1.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                quickAction.show(v);
            }
        });
    }
}

2.) The Activity extended the Base Activity

package com.waheguru.app;

import android.app.Activity;
import android.os.Bundle;

public class ABCActivity extends BaseActivityMenu  {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.home);
    }
}

So can any one help me where I am doing something wrong.

Answer 1

For this you have to create one header.xml which will be included in each and every layout for your activities as follows

header.xml

<RelativeLayout>
  <TextView android:id="@+id/txtHeading"
      .... />
</RelativeLayout>

activity_main.xml

<RelativeLayout>
  <!-- include your header here -->
  <include layout="@layout/header"
     ... />

  <!-- Rest of your views -->

</RelativeLayout>

BaseActivity

abstract class BaseActivity extends Activity {
  protected TextView txtHeading;
  public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
  }


  protected void setHeading(int resId) {
     if(txtHeading == null)
     txtHeading = findViewById(R.id.txtHeading);
     if(txtHeading != null)
       txtHeading.setText(resId);
  }
}

MainActivity

class MainActivity extends BaseActivity {
   public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      setHeading(R.string.heading_main);
   }
}

You can put as many views you want and manage common things in BaseActivity or BaseListActivity.

Answer 2

If you are making inheritance with activities and your base activity calls setContentView and after that the real activity calls setContentView the last call will set the layout for activity. So if you are looking for a solution where all activies have the same header component the are 2 ways.

1. For each activity layout xml you include that component

2. -You make function for baseActivity eg setContent(int layout_id) -You call that with your activity always. -Baseactivity inflates a root view with header and inflates layout_id view to that layout. -Then calls the actual setContentView with that component.

Answer 3

I think you should achieve it using Fragment , this may helps you.

1 - in main.xml , add:

<fragment
    android:id="@+id/header"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    class="com.package.name.HeaderPanel" />

//remaining is same 

2 - the BaseActivity which extends FragmentActivity :

public class BaseActivityMenu extends FragmentActivity {

    private static final String TAG = Default.class.getName() + " - ";
    private int mResLayoutId;

    public void onCreate(Bundle savedInstanceState, int resLayout){
        super.onCreate(savedInstanceState);
        setContentView(resLayout);
        mResLayoutId = resLayout;
        switch(mResLayoutId){
            // here change with your xml file
            case R.layout.home:
                // set here common control like header textview
                break;
            default:
                break;
        }
    }
}

3 - Now, you can extend your Activity with the BaseActivity . This will allow the Activity to be extended by FragmentActivity :

public class ABCActivity extends BaseActivityMenu {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState, R.layout.home);
    }
}

Answer 4

In code, your base activity is called ExampleActivity , but in your child class you are extending BaseActivityMenu . Don't know where its coming from.

Perhaps change:

public class ABCActivity extends BaseActivityMenu

To this:

public class ABCActivity extends ExampleActivity

Moreover, I would suggest you to define your base activity ( ExampleActivity ) as an Abstract class. For example:

public abstract class ExampleActivity extends Activity

Doing so will not define your base class as concrete and will make it easier to debug in case of problems.