利用Actionbar同样可以很轻松的实现下拉式的导航方式,相比与tab的方式下拉式的导航方式更类型于html中 的<select>标签。若想实现这种效 果:1)actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST)2)setListNavigationCallbacks(SpinnerAdapter adapter,ActionBar.OnNavigationListener callback).
首先是创建一个Fragment类:
package ccom.app.main;
import android.annotation.SuppressLint;
import android.app.Fragment;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.TextView;
@SuppressLint("NewApi")
public class MyFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
Context context = this.getActivity();
TextView tv = new TextView(context);
Bundle arc = this.getArguments();
int tabs=arc.getInt("key");
tv.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,
LayoutParams.WRAP_CONTENT));
tv.setText("hello actionbar "+tabs);
return tv;
}
}
main.xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Main" >
<LinearLayout
android:id="@+id/content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" />
</RelativeLayout>
自定义的用于显示textview的mytextview.xml:
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/text1"
android:textColor="#fff"
android:background="#696969"
android:layout_width="60sp"
android:layout_height="match_parent"
android:textAppearance="?android:attr/textAppearanceListItemSmall"
android:gravity="center_vertical"
android:paddingStart="?android:attr/listPreferredItemPaddingStart"
android:minHeight="?android:attr/listPreferredItemHeightSmall"
/>
Main.java
package ccom.app.main;
import android.annotation.SuppressLint;
import android.app.ActionBar;
import android.app.Activity;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.widget.ArrayAdapter;
@SuppressLint("NewApi")
public class Main extends Activity implements ActionBar.OnNavigationListener {
ActionBar actionBar = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
actionBar = this.getActionBar();
actionBar.setDisplayShowTitleEnabled(true);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);
actionBar.setListNavigationCallbacks(new ArrayAdapter(Main.this,
R.layout.mytextview, R.id.text1, new String[] { "tab1", "tab2",
"tab3" }), this);
}
@Override
public boolean onNavigationItemSelected(int itemPosition, long itemId) {
MyFragment mf = new MyFragment();
Bundle bundle = new Bundle();
bundle.putInt("key", itemPosition + 1);
mf.setArguments(bundle);
FragmentTransaction action = this.getFragmentManager()
.beginTransaction();
action.replace(R.id.content, mf);
action.commit();
return true;
}
}
实现的效果如图: