Android DrawerLayout实现NavigationView不记住上次所选选项

Android DrawLayout和NavigationView优化

android自带DrawLayout和NavigationView，使得我们可以将一些菜单隐藏起来，而不是放置在主屏幕上，然后可以通过滑动的方式将菜单显示出来，这种方式既节省了屏幕空间，又实现了非常好的动画效果，使用起来也很方便。之前使用的时候，在navigation上选中某个item后，退出drawLayout，默认会记住上一个的选项，感觉不是很好，后来实现了非记忆功能。

先看效果图吧。

下面直接上步骤和相关代码。

1.build.gradle引用两个依赖

 implementation 'de.hdodenhof:circleimageview:2.1.0'
 implementation 'com.android.support:design:28.0.0'

2.activity_main.xml:只是简单地放置一个CircleImageView

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/DrawerLayout"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:focusable="true"
        android:clickable="true"
        android:focusableInTouchMode="true"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    <android.support.design.widget.CoordinatorLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"

    >
            <android.support.constraint.ConstraintLayout
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:focusable="true"
                    android:focusableInTouchMode="true"
                    tools:context=".Acitivity.WorksIndexActivity">

                <de.hdodenhof.circleimageview.CircleImageView
                        android:layout_width="40dp"
                        android:layout_height="40dp"
                        android:src="@mipmap/image0"
                        android:id="@+id/avatar"
                        app:layout_constraintTop_toTopOf="parent" android:layout_marginTop="16dp"
                        app:layout_constraintStart_toStartOf="parent" android:layout_marginStart="16dp"
                />


            </android.support.constraint.ConstraintLayout>


    </android.support.design.widget.CoordinatorLayout>

    <android.support.design.widget.NavigationView android:layout_width="match_parent"
                                                  android:layout_height="match_parent"
                                                  android:id="@+id/nav_view"
                                                  android:layout_gravity="start"
                                                  app:menu="@menu/nav_menu"
                                                  app:headerLayout="@layout/nav_header"/>
</android.support.v4.widget.DrawerLayout>

3.在res文件夹下的layout新建nav_header.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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">
    <ImageView
            android:layout_width="0dp"
            android:layout_height="200dp"
            android:src="@mipmap/image2"
            android:id="@+id/imageView7" app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent"
            android:scaleType="fitXY" app:layout_constraintHorizontal_bias="0.0"/>
    <de.hdodenhof.circleimageview.CircleImageView
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:src="@mipmap/image0"
            android:id="@+id/imageView8" app:layout_constraintStart_toStartOf="@+id/imageView7"
            android:layout_marginStart="32dp" android:layout_marginBottom="32dp"
            app:layout_constraintBottom_toBottomOf="@+id/imageView7"/>
    <TextView
            android:text="ID:1106488127"
            android:textSize="12dp"
            android:textColor="@color/white"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/textView9" app:layout_constraintStart_toEndOf="@+id/imageView8"
            android:layout_marginStart="24dp" app:layout_constraintTop_toTopOf="@+id/imageView8"
            android:layout_marginTop="30dp"/>
    <TextView
            android:text="zoom"
            android:textSize="20dp"
            android:textColor="@color/white"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/textView11" android:layout_marginStart="24dp"
            app:layout_constraintStart_toEndOf="@+id/imageView8" android:layout_marginBottom="8dp"
            app:layout_constraintBottom_toTopOf="@+id/textView9"/>

</android.support.constraint.ConstraintLayout>

4.在res文件夹下新建文件夹menu，menu里面建立文件nav_menu.xml,注意这里多了个选项id为menu_none,title为空，并显示不可见，这里是退出drawerlayout后不记忆上次选择的关键，通过选择menu_none实现“曲线救国”

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <group android:checkableBehavior="single">
        <item android:id="@+id/index"
              android:icon="@mipmap/home"
              android:title="主页"/>
        <item android:id="@+id/discover"
              android:icon="@mipmap/faxian"
              android:title="发现"/>
        <item android:id="@+id/love"
              android:icon="@mipmap/aixin"
              android:title="我喜欢的作品"/>
        <item android:id="@+id/attention"
              android:icon="@mipmap/guanzhu"
              android:title="关注"/>
        <item android:id="@+id/info"
              android:icon="@mipmap/wodexiaoxi"
              android:title="我的信息"/>
        <item android:id="@+id/setting"
              android:icon="@mipmap/shezhi"
              android:title="设置"/>
        <item android:id="@+id/menu_none"
              android:title=""
              android:visible="false"/>

    </group>
</menu>

5.MainActivity实现，给drawerLayout增加监听事件。

public class MainActivity extends AppCompatActivity {

    private DrawerLayout drawerLayout;
    private NavigationView navigationView;

    private float CurrentSlideOffset = 0.0f;
    private Runnable ShouldHandleMenuClicked = null;


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

        drawerLayout = findViewById(R.id.DrawerLayout);
        navigationView = findViewById(R.id.nav_view);

        drawerLayout.addDrawerListener(new DrawerLayout.SimpleDrawerListener() {
            @Override
            public void onDrawerSlide(View drawerView, float slideOffset) {
                super.onDrawerSlide(drawerView, slideOffset);
                if (CurrentSlideOffset > slideOffset && slideOffset < 0.015f && ShouldHandleMenuClicked != null) {
                    ShouldHandleMenuClicked.run();
                    ShouldHandleMenuClicked = null;
                    runOnUiThread(() -> {
                        navigationView.setCheckedItem(R.id.menu_none);
                    });
                }
                CurrentSlideOffset = slideOffset;
            }
        });

        ImageView avatar = findViewById(R.id.avatar);
        avatar.setOnClickListener(v -> drawerLayout.openDrawer(GravityCompat.START));

        navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
                switch (menuItem.getItemId()) {
                    case R.id.index:
                        ShouldHandleMenuClicked = () -> {
                            Toast.makeText(MainActivity.this,"你点击了主页",Toast.LENGTH_SHORT).show();
                        };
                        break;
                    case R.id.discover:
                        ShouldHandleMenuClicked = () -> {
                            Toast.makeText(MainActivity.this,"你点击了发现",Toast.LENGTH_SHORT).show();
                        };
                        break;
                    case R.id.love:
                        ShouldHandleMenuClicked = () -> {
                            Toast.makeText(MainActivity.this,"你点击了我喜欢的作品",Toast.LENGTH_SHORT).show();
                        };
                        break;
                    case R.id.attention:
                        ShouldHandleMenuClicked = () -> {
                            Toast.makeText(MainActivity.this,"你点击了关注",Toast.LENGTH_SHORT).show();
                        };
                        break;
                    case R.id.info:
                        ShouldHandleMenuClicked = () -> {
                            Toast.makeText(MainActivity.this,"你点击了我的信息",Toast.LENGTH_SHORT).show();
                        };
                        break;
                    case R.id.setting:
                        ShouldHandleMenuClicked = () -> {
                            Toast.makeText(MainActivity.this,"你点击了设置",Toast.LENGTH_SHORT).show();
                        };
                        break;

                }
                drawerLayout.closeDrawers();
                return true;
            }
        });
    }
}

一些图标资源和用到的一个color资源就没有写出来了。