android 新建项目中去掉标题栏

1.新建new android application project

  theme选none 并打钩创建一个Blank Activity

 运行如下图所示：

2。若想把标题栏去掉，更改Manifestr的MainActivity 主题样式

>styles.xml中改

开始将<style name="AppTheme" parent="AppBaseTheme">

改为：<style name="AppTheme" parent="android:Theme.Light.NoTitleBar">//无标题白色背景

去行，闪退并报错：Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.

3。原因，是由于public class MainActivity extends ActionBarActivity在创建的时候继承了ActionBarActivity有标题的类，这样就会报错

更改继承FragmentActivity并把相应提示报错处理一下就可以。

具体代码如下：

package com.example.abc;

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.os.Build;

public class MainActivity extends FragmentActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment()).commit();
        }
    }

//    @Override
//    public boolean onCreateOptionsMenu(Menu menu) {
//
//        // Inflate the menu; this adds items to the action bar if it is present.
//        getMenuInflater().inflate(R.menu.main, menu);
//        return true;
//    }
//
//    @Override
//    public boolean onOptionsItemSelected(MenuItem item) {
//        // Handle action bar item clicks here. The action bar will
//        // automatically handle clicks on the Home/Up button, so long
//        // as you specify a parent activity in AndroidManifest.xml.
//        int id = item.getItemId();
//        if (id == R.id.action_settings) {
//            return true;
//        }
//        return super.onOptionsItemSelected(item);
//    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {

        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container,
                    false);
            return rootView;
        }
    }

}

运行正确：