简单的DrawerLayout实现方式

DrawerLayout最容易出错的地方就是布局,所以布局一定要写规范

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout 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:id="@+id/drawerLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <android.support.constraint.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
        <android.support.v4.view.ViewPager
            android:id="@+id/viewPager"
            android:layout_width="0dp"
            android:layout_height="0dp"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintBottom_toTopOf="@+id/navigation"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            />

        <android.support.design.widget.BottomNavigationView
            android:id="@+id/navigation"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginStart="0dp"
            android:layout_marginEnd="0dp"
            android:background="?android:attr/windowBackground"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:menu="@menu/navigation" />
    </android.support.constraint.ConstraintLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="left"
        android:background="#f00"
        android:orientation="vertical">
        <Button
            android:id="@+id/button1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:text="首页"/>
        <Button
            android:id="@+id/button2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:text="发现"/>
        <Button
            android:id="@+id/button3"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:text="我的"/>
    </LinearLayout>

</android.support.v4.widget.DrawerLayout>

接着就是DrawerLayout的实现步骤

第一步，先获取id,实现button的点击事件

		drawerLayout = findViewById(R.id.drawerLayout);
        findViewById(R.id.button1).setOnClickListener(this);
        findViewById(R.id.button2).setOnClickListener(this);
        findViewById(R.id.button3).setOnClickListener(this);

		 //点击事件
    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.button1:
                viewPager.setCurrentItem(0);
                drawerLayout.closeDrawers();
                break;
                case R.id.button2:
                viewPager.setCurrentItem(1);
                drawerLayout.closeDrawers();
                break;
                case R.id.button3:
                viewPager.setCurrentItem(2);
                drawerLayout.closeDrawers();
                break;
        }
    }

第二步，可有可无，设置DrawerLayout监听，设置关闭时的弹框

drawerLayout.addDrawerListener(new DrawerLayout.DrawerListener() {
            @Override
            public void onDrawerSlide(@NonNull View view, float v) {

            }

            @Override
            public void onDrawerOpened(@NonNull View view) {

            }

            @Override
            public void onDrawerClosed(@NonNull View view) {
                Toast.makeText(MainActivity.this,"DrawerLayout已关闭",Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onDrawerStateChanged(int i) {

            }
        });