CardView是实现卡片式布局效果的重要控件，和CoordinatorLayout一样也是一个特殊的FrameLayout
CardView_cardBackgroundColor 设置背景色CardView_cardCornerRadius 设置圆角大小CardView_cardElevation 设置z轴阴影CardView_cardMaxElevation 设置z轴最大高度值CardView_cardUseCompatPadding 是否使用CompadPaddingCardView_cardPReventCornerOverlap 是否使用PreventCornerOverlapCardView_contentPadding 内容的paddingCardView_contentPaddingLeft 内容的左paddingCardView_contentPaddingTop 内容的上paddingCardView_contentPaddingRight 内容的右paddingCardView_contentPaddingBottom 内容的底paddingcard_view:cardUseCompatPadding 设置内边距，V21+的版本和之前的版本仍旧具有一样的计算方式
card_view:cardPreventConrerOverlap 在V20和之前的版本中添加内边距，这个属性为了防止内容和边角的重叠
AppBarLayout，ToolBar中不使用AppBarLayout，ToolBar就会被其他布局遮挡，因为他们的父布局是CoordinatorLayout，属于FrameLayout。 使用了AppBarLayout，就赋予了起子View app:layout_scrollFlags=”scroll|enterAlways|snap” 这时，外界布局（如，RecyclerView）加上app:layout_behavior=”@string/appbar_scrolling_view_behavior” 就可以使滑动传递给带有app:layout_scrollFlags=”scroll|enterAlways|snap属性的布局。
CollapsingToolbarLayout是一个专业作用在ToolBar之上的布局，不能独立使用，只能嵌套在AppBarLayout内。当使用CollapsingToolbarLayout的时候把app:layout_scrollFlags属性移至CollapsingToolbarLayout中。然后在CollapsingToolbarLayout子View中添加app:layout_collapseMode=”parallax”类型的属性。
为了充分利用系统状态栏属性：使用 android:fitsSystemWindows=”true” 设置全屏：
if (Build.VERSION.SDK_INT >= 21) { View decorView = getWindow().getDecorView(); decorView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN | View.SYSTEM_UI_FLAG_LAYOUT_STABLE); getWindow().setStatusBarColor(Color.TRANSPARENT); }下面看效果：来自 第二行代码 
activity_main.xml
<?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" android:id="@+id/drawer_layout" 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.design.widget.AppBarLayout android:layout_width="match_parent" android:layout_height="wrap_content"> <android.support.v7.widget.Toolbar android:id="@+id/toolbar" android:layout_width="match_parent" android:layout_height="?attr/actionBarSize" android:background="?attr/colorPrimary" android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" app:popupTheme="@style/ThemeOverlay.AppCompat.Light" app:layout_scrollFlags="scroll|enterAlways|snap" /> </android.support.design.widget.AppBarLayout> <android.support.v4.widget.SwipeRefreshLayout android:id="@+id/swipe_refresh" android:layout_width="match_parent" android:layout_height="match_parent" app:layout_behavior="@string/appbar_scrolling_view_behavior"> <android.support.v7.widget.RecyclerView android:id="@+id/recycler_view" android:layout_width="match_parent" android:layout_height="match_parent" /> </android.support.v4.widget.SwipeRefreshLayout> <android.support.design.widget.FloatingActionButton android:id="@+id/fab" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="bottom|end" android:layout_margin="16dp" android:src="@drawable/ic_done" /> </android.support.design.widget.CoordinatorLayout> <android.support.design.widget.NavigationView android:id="@+id/nav_view" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_gravity="start" app:headerLayout="@layout/nav_header" app:menu="@menu/nav_menu" /></android.support.v4.widget.DrawerLayout>package com.example.materialtest;import android.os.Bundle;import android.support.design.widget.FloatingActionButton;import android.support.design.widget.NavigationView;import android.support.design.widget.Snackbar;import android.support.v4.view.GravityCompat;import android.support.v4.widget.DrawerLayout;import android.support.v4.widget.SwipeRefreshLayout;import android.support.v7.app.ActionBar;import android.support.v7.app.AppCompatActivity;import android.support.v7.widget.GridLayoutManager;import android.support.v7.widget.RecyclerView;import android.support.v7.widget.Toolbar;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.widget.Toast;import java.util.ArrayList;import java.util.List;import java.util.Random;public class MainActivity extends AppCompatActivity { private DrawerLayout mDrawerLayout; private Fruit[] fruits = {new Fruit("Apple", R.drawable.apple), new Fruit("Banana", R.drawable.banana), new Fruit("Orange", R.drawable.orange), new Fruit("Watermelon", R.drawable.watermelon), new Fruit("Pear", R.drawable.pear), new Fruit("Grape", R.drawable.grape), new Fruit("Pineapple", R.drawable.pineapple), new Fruit("Strawberry", R.drawable.strawberry), new Fruit("Cherry", R.drawable.cherry), new Fruit("Mango", R.drawable.mango)}; private List<Fruit> fruitList = new ArrayList<>(); private FruitAdapter adapter; private SwipeRefreshLayout swipeRefresh; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout); NavigationView navView = (NavigationView) findViewById(R.id.nav_view); ActionBar actionBar = getSupportActionBar(); if (actionBar != null) { actionBar.setDisplayHomeAsUpEnabled(true); actionBar.setHomeAsUpIndicator(R.drawable.ic_menu); } navView.setCheckedItem(R.id.nav_call); navView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() { @Override public boolean onNavigationItemSelected(MenuItem item) { mDrawerLayout.closeDrawers(); return true; } }); FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); fab.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Snackbar.make(view, "Data deleted", Snackbar.LENGTH_SHORT) .setAction("Undo", new View.OnClickListener() { @Override public void onClick(View v) { Toast.makeText(MainActivity.this, "Data restored", Toast.LENGTH_SHORT).show(); } }) .show(); } }); initFruits(); RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recycler_view); GridLayoutManager layoutManager = new GridLayoutManager(this, 2); recyclerView.setLayoutManager(layoutManager); adapter = new FruitAdapter(fruitList); recyclerView.setAdapter(adapter); swipeRefresh = (SwipeRefreshLayout) findViewById(R.id.swipe_refresh); swipeRefresh.setColorSchemeResources(R.color.colorPrimary); swipeRefresh.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() { @Override public void onRefresh() { refreshFruits(); } }); } private void refreshFruits() { new Thread(new Runnable() { @Override public void run() { try { Thread.sleep(2000); } catch (InterruptedException e) { e.printStackTrace(); } runOnUiThread(new Runnable() { @Override public void run() { initFruits(); adapter.notifyDataSetChanged(); swipeRefresh.setRefreshing(false); } }); } }).start(); } private void initFruits() { fruitList.clear(); for (int i = 0; i < 50; i++) { Random random = new Random(); int index = random.nextInt(fruits.length); fruitList.add(fruits[index]); } } public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.toolbar, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case android.R.id.home: mDrawerLayout.openDrawer(GravityCompat.START); break; case R.id.backup: Toast.makeText(this, "You clicked Backup", Toast.LENGTH_SHORT).show(); break; case R.id.delete: Toast.makeText(this, "You clicked Delete", Toast.LENGTH_SHORT).show(); break; case R.id.settings: Toast.makeText(this, "You clicked Settings", Toast.LENGTH_SHORT).show(); break; default: } return true; }}activity_fruit.xml
<?xml version="1.0" encoding="utf-8"?><android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" android:fitsSystemWindows="true"> <android.support.design.widget.AppBarLayout android:id="@+id/appBar" android:layout_width="match_parent" android:layout_height="250dp" android:fitsSystemWindows="true"> <android.support.design.widget.CollapsingToolbarLayout android:id="@+id/collapsing_toolbar" android:layout_width="match_parent" android:layout_height="match_parent" android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" android:fitsSystemWindows="true" app:contentScrim="?attr/colorPrimary" app:layout_scrollFlags="scroll|exitUntilCollapsed"> <ImageView android:id="@+id/fruit_image_view" android:layout_width="match_parent" android:layout_height="match_parent" android:scaleType="centerCrop" android:fitsSystemWindows="true" app:layout_collapseMode="parallax" /> <android.support.v7.widget.Toolbar android:id="@+id/toolbar" android:layout_width="match_parent" android:layout_height="?attr/actionBarSize" app:layout_collapseMode="pin" /> </android.support.design.widget.CollapsingToolbarLayout> </android.support.design.widget.AppBarLayout> <android.support.v4.widget.NestedScrollView android:layout_width="match_parent" android:layout_height="match_parent" app:layout_behavior="@string/appbar_scrolling_view_behavior"> <LinearLayout android:orientation="vertical" android:layout_width="match_parent" android:layout_height="wrap_content"> <android.support.v7.widget.CardView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginBottom="15dp" android:layout_marginLeft="15dp" android:layout_marginRight="15dp" android:layout_marginTop="35dp" app:cardCornerRadius="4dp"> <TextView android:id="@+id/fruit_content_text" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_margin="10dp" /> </android.support.v7.widget.CardView> </LinearLayout> </android.support.v4.widget.NestedScrollView> <android.support.design.widget.FloatingActionButton android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_margin="16dp" android:src="@drawable/ic_comment" app:layout_anchor="@id/appBar" app:layout_anchorGravity="bottom|end" /></android.support.design.widget.CoordinatorLayout>package com.example.materialtest;import android.content.Intent;import android.graphics.Color;import android.support.design.widget.CollapsingToolbarLayout;import android.support.v7.app.ActionBar;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.support.v7.widget.Toolbar;import android.view.MenuItem;import android.widget.ImageView;import android.widget.TextView;import com.bumptech.glide.Glide;public class FruitActivity extends AppCompatActivity { public static final String FRUIT_NAME = "fruit_name"; public static final String FRUIT_IMAGE_ID = "fruit_image_id"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_fruit); Intent intent = getIntent(); String fruitName = intent.getStringExtra(FRUIT_NAME); int fruitImageId = intent.getIntExtra(FRUIT_IMAGE_ID, 0); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); CollapsingToolbarLayout collapsingToolbar = (CollapsingToolbarLayout) findViewById(R.id.collapsing_toolbar); ImageView fruitImageView = (ImageView) findViewById(R.id.fruit_image_view); TextView fruitContentText = (TextView) findViewById(R.id.fruit_content_text); setSupportActionBar(toolbar); ActionBar actionBar = getSupportActionBar(); if (actionBar != null) { actionBar.setDisplayHomeAsUpEnabled(true); } collapsingToolbar.setTitle(fruitName); Glide.with(this).load(fruitImageId).into(fruitImageView); String fruitContent = generateFruitContent(fruitName); fruitContentText.setText(fruitContent); } private String generateFruitContent(String fruitName) { StringBuilder fruitContent = new StringBuilder(); for (int i = 0; i < 500; i++) { fruitContent.append(fruitName); } return fruitContent.toString(); } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case android.R.id.home: finish(); return true; } return super.onOptionsItemSelected(item); }}fruit_item.xml
<?xml version="1.0" encoding="utf-8"?><android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_margin="5dp" app:cardCornerRadius="4dp"> <LinearLayout android:orientation="vertical" android:layout_width="match_parent" android:layout_height="wrap_content"> <ImageView android:id="@+id/fruit_image" android:layout_width="match_parent" android:layout_height="100dp" android:scaleType="centerCrop" /> <TextView android:id="@+id/fruit_name" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_horizontal" android:layout_margin="5dp" android:textSize="16sp" /> </LinearLayout></android.support.v7.widget.CardView>package com.example.materialtest;import android.content.Context;import android.content.Intent;import android.support.v7.widget.CardView;import android.support.v7.widget.RecyclerView;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import android.widget.TextView;import com.bumptech.glide.Glide;import java.util.List;public class FruitAdapter extends RecyclerView.Adapter<FruitAdapter.ViewHolder>{ private static final String TAG = "FruitAdapter"; private Context mContext; private List<Fruit> mFruitList; static class ViewHolder extends RecyclerView.ViewHolder { CardView cardView; ImageView fruitImage; TextView fruitName; public ViewHolder(View view) { super(view); cardView = (CardView) view; fruitImage = (ImageView) view.findViewById(R.id.fruit_image); fruitName = (TextView) view.findViewById(R.id.fruit_name); } } public FruitAdapter(List<Fruit> fruitList) { mFruitList = fruitList; } @Override public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { if (mContext == null) { mContext = parent.getContext(); } View view = LayoutInflater.from(mContext).inflate(R.layout.fruit_item, parent, false); final ViewHolder holder = new ViewHolder(view); holder.cardView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { int position = holder.getAdapterPosition(); Fruit fruit = mFruitList.get(position); Intent intent = new Intent(mContext, FruitActivity.class); intent.putExtra(FruitActivity.FRUIT_NAME, fruit.getName()); intent.putExtra(FruitActivity.FRUIT_IMAGE_ID, fruit.getImageId()); mContext.startActivity(intent); } }); return holder; } @Override public void onBindViewHolder(ViewHolder holder, int position) { Fruit fruit = mFruitList.get(position); holder.fruitName.setText(fruit.getName()); Glide.with(mContext).load(fruit.getImageId()).into(holder.fruitImage); } @Override public int getItemCount() { return mFruitList.size(); }}public class Fruit { private String name; private int imageId; public Fruit(String name, int imageId) { this.name = name; this.imageId = imageId; } public String getName() { return name; } public int getImageId() { return imageId; }}新闻热点
疑难解答
