<style name="TranslucentTheme" parent="AppTheme">
  <!--在Android 4.4之前的版本上运行，直接跟随系统主题-->
</style>

values-v19/style.xml：

<style name="TranslucentTheme" parent="Theme.AppCompat.Light.DarkActionBar">
  <item name="android:windowTranslucentStatus">true</item>
  <item name="android:windowTranslucentNavigation">true</item>
</style>

<style name="TranslucentTheme" parent="Theme.AppCompat.Light.DarkActionBar">
  <item name="android:windowTranslucentStatus">false</item>
  <item name="android:windowTranslucentNavigation">true</item>
  <!--Android 5.x开始需要把颜色设置透明，否则导航栏会呈现系统默认的浅灰色-->
  <item name="android:statusBarColor">@android:color/transparent</item>
</style>

<activity android:name=".ImageActivity" android:theme="@style/TranslucentTheme" />
<activity android:name=".ColorActivity" android:theme="@style/TranslucentTheme" />

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:background="@drawable/imgs_bj"
  android:fitsSystemWindows="true">

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:background="@color/colorPrimary" //根布局背景设置成“标题布局”想要的颜色
  android:fitsSystemWindows="true"
  android:orientation="vertical">

  <!--标题布局-->
  <RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="55dp"
    android:background="@color/color_31c27c">

    <TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerInParent="true"
      android:text="这是标题"
      android:textColor="@android:color/white"
      android:textSize="20sp" />

  </RelativeLayout>

  <!--内容布局-->
  <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/white" //内容区域背景设置成白色
    android:gravity="center"
    android:orientation="vertical">

    <Button
      android:layout_marginTop="120dp"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:padding="8dp"
      android:text="显示信息"
      android:onClick="showMsg"
      />
  </LinearLayout>

</LinearLayout>

public abstract class BaseColorActivity extends AppCompatActivity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //这一行注意！看本文最后的说明！！！！
    supportRequestWindowFeature(Window.FEATURE_NO_TITLE);

    setContentView(getLayoutResId());//把设置布局文件的操作交给继承的子类

    ViewGroup contentFrameLayout = (ViewGroup) findViewById(Window.ID_ANDROID_CONTENT);
    View parentView = contentFrameLayout.getChildAt(0);
    if (parentView != null && Build.VERSION.SDK_INT >= 14) {
      parentView.setFitsSystemWindows(true);
    }
  }

  /**
   * 返回当前Activity布局文件的id
   *
   * @return
   */
  abstract protected int getLayoutResId();

}

public class ColorActivity extends BaseColorActivity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //这里不需要写setContentView()！
  }

  @Override
  protected int getLayoutResId() {
    //onCreate的方法中不需要写setContentView(),直接把当前activity的布局文件在这里返回就行了！
    return R.layout.activity_color;
  }
}

public class StatusBarCompat {

  private static final int INVALID_VAL = -1;
  private static final int COLOR_DEFAULT = Color.parseColor("#20000000");

  @TargetApi(Build.VERSION_CODES.LOLLIPOP)
  public static void compat(Activity activity, int statusColor)
  {

    //当前手机版本为5.0及以上 
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
    {
      if (statusColor != INVALID_VAL)
      {
        activity.getWindow().setStatusBarColor(statusColor);
      }
      return;
    }

    //当前手机版本为4.4
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT && Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP)
    {
      int color = COLOR_DEFAULT;
      ViewGroup contentView = (ViewGroup) activity.findViewById(android.R.id.content);
      if (statusColor != INVALID_VAL)
      {
        color = statusColor;
      }
      View statusBarView = new View(activity);
      ViewGroup.LayoutParams lp = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
          getStatusBarHeight(activity));
      statusBarView.setBackgroundColor(color);
      contentView.addView(statusBarView, lp);
    }

  }

  public static void compat(Activity activity)
  {
    compat(activity, INVALID_VAL);
  }


  public static int getStatusBarHeight(Context context)
  {
    int result = 0;
    int resourceId = context.getResources().getIdentifier("status_bar_height", "dimen", "android");
    if (resourceId > 0)
    {
      result = context.getResources().getDimensionPixelSize(resourceId);
    }
    return result;
  }

}

//第二个参数是想要设置的颜色
StatusBarCompat.compat(this, Color.RED);

public class BaseActivity extends AppCompatActivity {

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

    StatusBarCompat.compat(this, Color.RED);
  }
}

supportRequestWindowFeature(Window.FEATURENOTITLE)

requestWindowFeature(Window.FEATURENOTITLE)