状态栏处理流程图

1.自定义导航栏

• 自定义导航栏UI.layout

定义导航栏上有哪些元素以及其布局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:background="@color/colorPrimaryDark"
    android:layout_height="44dp">

    <TextView
        android:id="@+id/title_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:textSize="17dp"
        android:textColor="@color/colorWhite"/>

    <TextView
        android:id="@+id/back_item_btn"
        android:layout_width="22dp"
        android:layout_height="22dp"
        android:layout_centerVertical="true"
        android:layout_alignParentLeft="true"
        android:layout_marginLeft="20dp"
        android:background="@mipmap/back_arrow"
        android:textColor="@color/colorWhite"
        />

    <TextView
        android:id="@+id/right_item_btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@color/colorClear"
        android:layout_centerVertical="true"
        android:layout_alignParentRight="true"
        android:textColor="@color/colorWhite"
        android:layout_marginRight="20dp"/>
</RelativeLayout>

• 自定义导航栏.java

1.定义变量引用布局文件上的UI元素
2.定义通用逻辑和响应事件

package mu.navigationbardemo;

import android.app.Activity;
import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.RelativeLayout;
import android.widget.TextView;

import java.util.jar.Attributes;

public class NavigationBarLayout extends RelativeLayout {

    public TextView titleText;
    public TextView backItemBtn;
    public TextView rightItemBtn;

    public  NavigationBarLayout(Context context, AttributeSet attrs){
        super(context, attrs);
        LayoutInflater.from(context).inflate(R.layout.layout_navigation_bar,this);
        this.titleText = (TextView) findViewById(R.id.title_text);
        this.backItemBtn = (TextView) findViewById(R.id.back_item_btn);
        this.rightItemBtn = (TextView) findViewById(R.id.right_item_btn);

        backItemBtn.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                ((Activity) getContext()).finish();
            }
        });

        rightItemBtn.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {

            }
        });

    }
}

在Activity的layout中引用自定义导航栏

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <mu.navigationbardemo.NavigationBarLayout
        android:id="@+id/navigation_bar_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>


</RelativeLayout>

在Activity的java文件中引用自定义导航栏

public class MainActivity extends Activity {

    private Button nextBtn;
    private NavigationBarLayout navigationBar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //隐藏系统原生导航栏
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);
        nextBtn = (Button) findViewById(R.id.next_btn);
        navigationBar = (NavigationBarLayout) findViewById(R.id.navigation_bar_layout);
        //设置导航栏标题
        navigationBar.titleText.setText("首页");
        //因为是首页，隐藏返回按钮
        navigationBar.backItemBtn.setEnabled(false);//返回按钮不可用
        navigationBar.backItemBtn.setVisibility(View.GONE);//返回按钮不可见
    }
}

隐藏系统导航栏的Activity需要继承自Activity,否则不生效