CoordinatorLayout布局的使用方式

转载自：http://www.jianshu.com/p/97206f5973c5

这篇文章写的关于CoordinatorLayout的使用方法，写的很细致，层次分明适合初学者学习使用

作为Android的控件, CoordinatorLayout已经加入最新的HelloWorld项目中, 也是Material风格的重要组件, 协调(Coordinate)其他组件, 实现联动. 那么让我们来看看这个动画效果怎么用吧?

本文源码的GitHub下载地址 



联动效果

1. 准备

首先新建HelloWorld项目.

在项目的build.gradle文件中, 引入头像控件库和CardView库, 在本例中会使用.

compile 'de.hdodenhof:circleimageview:1.3.0'
compile 'com.android.support:cardview-v7:23.1.0'
compile 'com.jakewharton:butterknife:7.0.1'

2. 页面

在

activity_main.xml

中, 保留CoordinatorLayout和AppBarLayout,
重新编写页面.

android:fitsSystemWindows="true"

 这句也需要去掉, 本例需要保留最上面的状态栏(status
bar), 这个属性会导致重叠, 默认false.

activity_main.xml代码

<android.support.design.widget.CoordinatorLayout
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"
android:fitsSystemWindows="true"
tools:context=".MainActivity">

<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/AppTheme.AppBarOverlay">

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

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

修改主题颜色, 粉色符合风格

<color name="colorPrimary">#FFCCCC</color>
<color name="colorPrimaryDark">#FF00FF</color>

在AppBarLayout中, 添加CollapsingToolbarLayout控件, CollapsingToolbar会滚动消失, 被ToolBar替换, 实现滚动动画.

<android.support.design.widget.CollapsingToolbarLayout
android:layout_width="match_parent"
android:layout_height="450dp"
app:layout_scrollFlags="scroll|exitUntilCollapsed|snap">

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

app:layout_scrollFlags

的属性, scroll滑动, exitUntilCollapsed退出到最小,
snap自动滑动动画, 定义CollapsingToolbarLayout的滑动属性.

CollapsingToolbarLayout划分两部分, 一部分大图, 一部分文字.

<ImageView
android:layout_width="match_parent"
android:layout_height="300dp"
android:scaleType="centerCrop"
android:src="@drawable/large"
app:layout_collapseMode="parallax" />

<FrameLayout
android:layout_width="match_parent"
android:layout_height="150dp"
android:layout_gravity="bottom|center_horizontal"
android:background="@color/colorPrimary"
app:layout_collapseMode="parallax">

<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_gravity="center">

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:gravity="bottom|center"
android:text="@string/person_name"
android:textColor="@android:color/white"
android:textSize="30sp" />

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_marginTop="4dp"
android:text="@string/person_title"
android:textColor="@android:color/white"/>
</LinearLayout>
</FrameLayout>

app:layout_collapseMode="parallax"

折叠时的视差效果, 自动滑动.

效果


CollapsingToolbarLayout

添加NestedScrollView, 文字的滚动视图.

<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="none"
app:behavior_overlapTop="30dp"
app:layout_behavior="@string/appbar_scrolling_view_behavior">

<android.support.v7.widget.CardView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="8dp"
app:cardElevation="8dp"
app:contentPadding="16dp">

<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:lineSpacingExtra="8dp"
android:text="@string/person_intro"/>

</android.support.v7.widget.CardView>
</android.support.v4.widget.NestedScrollView>

app:behavior_overlapTop="30dp"

, The amount that the
scrolling view should overlap the bottom of any AppBarLayout. 使ScrollView压在AppBarLayout上面一段长度.

添加ToolBar, 滚动结束的效果图.

<android.support.v7.widget.Toolbar
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/colorPrimary"
app:layout_anchor="@id/main_fl_title"
app:theme="@style/ThemeOverlay.AppCompat.Dark">

<LinearLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:orientation="horizontal">

<Space
android:layout_width="@dimen/image_final_width"
android:layout_height="@dimen/image_final_width" />

<TextView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center_vertical"
android:text="@string/person_name"
android:textColor="@android:color/white"
android:textSize="20sp"/>

</LinearLayout>

</android.support.v7.widget.Toolbar>

ToolBar是工具栏, 滑动完成时, 在最上部显示. 

Space

预留头像的位置.

圆形头像CircleImageView显示(使用第三方库)

<de.hdodenhof.circleimageview.CircleImageView
android:layout_width="120dp"
android:layout_height="120dp"
android:layout_gravity="center"
android:src="@drawable/small"
app:border_color="@android:color/white"
app:border_width="2dp"
app:layout_behavior=".AvatarImageBehavior" />

头像控件的滑动行为是自定义的类, 具体行为参考注释. 判断起始和终止位置, child和dependency视图联动, 这里是图像视图和Toolbar联动.

/**
* 图片控件位置动画
*
* @author wangchenlong
*/
@SuppressWarnings("unused")
public class AvatarImageBehavior extends CoordinatorLayout.Behavior<CircleImageView> {

private final static float MIN_AVATAR_PERCENTAGE_SIZE = 0.3f;
private final static int EXTRA_FINAL_AVATAR_PADDING = 80;

private int mStartYPosition; // 起始的Y轴位置
private int mFinalYPosition; // 结束的Y轴位置
private int mStartHeight; // 开始的图片高度
private int mFinalHeight; // 结束的图片高度
private int mStartXPosition; // 起始的X轴高度
private int mFinalXPosition; // 结束的X轴高度
private float mStartToolbarPosition; // Toolbar的起始位置

private final Context mContext;
private float mAvatarMaxSize;

public AvatarImageBehavior(Context context, AttributeSet attrs) {
mContext = context;
init();
}

private void init() {
bindDimensions();
}

private void bindDimensions() {
mAvatarMaxSize = mContext.getResources().getDimension(R.dimen.image_width);
}

@Override
public boolean layoutDependsOn(CoordinatorLayout parent, CircleImageView child, View dependency) {
// 依赖Toolbar控件
return dependency instanceof Toolbar;
}

@Override
public boolean onDependentViewChanged(CoordinatorLayout parent, CircleImageView child, View dependency) {

// 初始化属性
shouldInitProperties(child, dependency);

// 最大滑动距离: 起始位置-状态栏高度
final int maxScrollDistance = (int) (mStartToolbarPosition - getStatusBarHeight());

// 滑动的百分比
float expandedPercentageFactor = dependency.getY() / maxScrollDistance;

// Y轴距离
float distanceYToSubtract = ((mStartYPosition - mFinalYPosition)
* (1f - expandedPercentageFactor)) + (child.getHeight() / 2);

// X轴距离
float distanceXToSubtract = ((mStartXPosition - mFinalXPosition)
* (1f - expandedPercentageFactor)) + (child.getWidth() / 2);

// 高度减小
float heightToSubtract = ((mStartHeight - mFinalHeight) * (1f - expandedPercentageFactor));

// 图片位置
child.setY(mStartYPosition - distanceYToSubtract);
child.setX(mStartXPosition - distanceXToSubtract);

// 图片大小
CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams) child.getLayoutParams();
lp.width = (int) (mStartHeight - heightToSubtract);
lp.height = (int) (mStartHeight - heightToSubtract);
child.setLayoutParams(lp);

return true;
}

/**
* 初始化动画值
*
* @param child      图片控件
* @param dependency ToolBar
*/
private void shouldInitProperties(CircleImageView child, View dependency) {

// 图片控件中心
if (mStartYPosition == 0)
mStartYPosition = (int) (child.getY() + (child.getHeight() / 2));

// Toolbar中心
if (mFinalYPosition == 0)
mFinalYPosition = (dependency.getHeight() / 2);

// 图片高度
if (mStartHeight == 0)
mStartHeight = child.getHeight();

// Toolbar缩略图高度
if (mFinalHeight == 0)
mFinalHeight = mContext.getResources().getDimensionPixelOffset(R.dimen.image_final_width);

// 图片控件水平中心
if (mStartXPosition == 0)
mStartXPosition = (int) (child.getX() + (child.getWidth() / 2));

// 边缘+缩略图宽度的一半
if (mFinalXPosition == 0)
mFinalXPosition = mContext.getResources().getDimensionPixelOffset(R.dimen.abc_action_bar_content_inset_material) + (mFinalHeight / 2);

// Toolbar的起始位置
if (mStartToolbarPosition == 0)
mStartToolbarPosition = dependency.getY() + (dependency.getHeight() / 2);
}

// 获取状态栏高度
public int getStatusBarHeight() {
int result = 0;
int resourceId = mContext.getResources().getIdentifier("status_bar_height", "dimen", "android");

if (resourceId > 0) {
result = mContext.getResources().getDimensionPixelSize(resourceId);
}
return result;
}
}

添加需要使用的id, 

activity_main.xml

如下

<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="false"
tools:context=".MainActivity">

<android.support.design.widget.AppBarLayout
android:id="@+id/main_abl_app_bar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

<android.support.design.widget.CollapsingToolbarLayout
android:layout_width="match_parent"
android:layout_height="450dp"
app:layout_scrollFlags="scroll|exitUntilCollapsed|snap">

<ImageView
android:id="@+id/main_iv_placeholder"
android:layout_width="match_parent"
android:layout_height="300dp"
android:scaleType="centerCrop"
android:src="@drawable/large"
app:layout_collapseMode="parallax" />

<FrameLayout
android:id="@+id/main_fl_title"
android:layout_width="match_parent"
android:layout_height="150dp"
android:layout_gravity="bottom|center_horizontal"
android:background="@color/colorPrimary"
app:layout_collapseMode="parallax">

<LinearLayout
android:id="@+id/main_ll_title_container"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:orientation="vertical">

<TextView
android:layout_marginTop="@dimen/title_margin"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:gravity="bottom|center"
android:text="@string/person_name"
android:textColor="@android:color/white"
android:textSize="30sp"/>

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_marginTop="4dp"
android:text="@string/person_title"
android:textColor="@android:color/white" />
</LinearLayout>
</FrameLayout>
</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"
android:scrollbars="none"
app:behavior_overlapTop="30dp"
app:layout_behavior="@string/appbar_scrolling_view_behavior">

<android.support.v7.widget.CardView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="8dp"
app:cardElevation="8dp"
app:contentPadding="16dp">

<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:lineSpacingExtra="8dp"
android:text="@string/person_intro" />

</android.support.v7.widget.CardView>

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

<android.support.v7.widget.Toolbar
android:id="@+id/main_tb_toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/colorPrimary"
app:layout_anchor="@id/main_fl_title"
app:theme="@style/ThemeOverlay.AppCompat.Dark">

<LinearLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:orientation="horizontal">

<Space
android:layout_width="@dimen/image_final_width"
android:layout_height="@dimen/image_final_width" />

<TextView
android:id="@+id/main_tv_title"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginLeft="8dp"
android:gravity="center_vertical"
android:text="@string/person_name"
android:textColor="@android:color/white"
android:textSize="20sp"
android:visibility="invisible"/>

</LinearLayout>

</android.support.v7.widget.Toolbar>

<de.hdodenhof.circleimageview.CircleImageView
android:layout_width="@dimen/image_width"
android:layout_height="@dimen/image_width"
android:layout_gravity="center"
android:src="@drawable/small"
app:border_color="@android:color/white"
app:border_width="2dp"
app:layout_behavior=".AvatarImageBehavior" />

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

效果


页面

3. 逻辑

在onCreate里面设置滑动逻辑, 设置两个动画: 监听AppBar的滑动, 处理Toolbar和Title的显示; 自动滑动效果.

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

mTbToolbar.setTitle("");

// AppBar的监听
mAblAppBar.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
@Override
public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
int maxScroll = appBarLayout.getTotalScrollRange();
float percentage = (float) Math.abs(verticalOffset) / (float) maxScroll;
handleAlphaOnTitle(percentage);
handleToolbarTitleVisibility(percentage);
}
});

initParallaxValues(); // 自动滑动效果
}

根据滑动百分比, 设置Title和Toolbar的显示与消失, 使用Alpha动画.

// 处理ToolBar的显示
private void handleToolbarTitleVisibility(float percentage) {
if (percentage >= PERCENTAGE_TO_SHOW_TITLE_AT_TOOLBAR) {
if (!mIsTheTitleVisible) {
startAlphaAnimation(mTvToolbarTitle, ALPHA_ANIMATIONS_DURATION, View.VISIBLE);
mIsTheTitleVisible = true;
}
} else {
if (mIsTheTitleVisible) {
startAlphaAnimation(mTvToolbarTitle, ALPHA_ANIMATIONS_DURATION, View.INVISIBLE);
mIsTheTitleVisible = false;
}
}
}

// 控制Title的显示
private void handleAlphaOnTitle(float percentage) {
if (percentage >= PERCENTAGE_TO_HIDE_TITLE_DETAILS) {
if (mIsTheTitleContainerVisible) {
startAlphaAnimation(mLlTitleContainer, ALPHA_ANIMATIONS_DURATION, View.INVISIBLE);
mIsTheTitleContainerVisible = false;
}
} else {
if (!mIsTheTitleContainerVisible) {
startAlphaAnimation(mLlTitleContainer, ALPHA_ANIMATIONS_DURATION, View.VISIBLE);
mIsTheTitleContainerVisible = true;
}
}
}

// 设置渐变的动画
public static void startAlphaAnimation(View v, long duration, int visibility) {
AlphaAnimation alphaAnimation = (visibility == View.VISIBLE)
? new AlphaAnimation(0f, 1f)
: new AlphaAnimation(1f, 0f);

alphaAnimation.setDuration(duration);
alphaAnimation.setFillAfter(true);
v.startAnimation(alphaAnimation);
}

自动滑动动画, 当到一定比例时展开或关闭.

// 设置自动滑动的动画效果
private void initParallaxValues() {
CollapsingToolbarLayout.LayoutParams petDetailsLp =
(CollapsingToolbarLayout.LayoutParams) mIvPlaceholder.getLayoutParams();

CollapsingToolbarLayout.LayoutParams petBackgroundLp =
(CollapsingToolbarLayout.LayoutParams) mFlTitleContainer.getLayoutParams();

petDetailsLp.setParallaxMultiplier(0.9f);
petBackgroundLp.setParallaxMultiplier(0.3f);

mIvPlaceholder.setLayoutParams(petDetailsLp);
mFlTitleContainer.setLayoutParams(petBackgroundLp);
}

最终逻辑

public class MainActivity extends AppCompatActivity {

// 控制ToolBar的变量
private static final float PERCENTAGE_TO_SHOW_TITLE_AT_TOOLBAR = 0.9f;
private static final float PERCENTAGE_TO_HIDE_TITLE_DETAILS = 0.3f;

private static final int ALPHA_ANIMATIONS_DURATION = 200;

private boolean mIsTheTitleVisible = false;
private boolean mIsTheTitleContainerVisible = true;

@Bind(R.id.main_iv_placeholder)
ImageView mIvPlaceholder; // 大图片

@Bind(R.id.main_ll_title_container)
LinearLayout mLlTitleContainer; // Title的LinearLayout

@Bind(R.id.main_fl_title)
FrameLayout mFlTitleContainer; // Title的FrameLayout

@Bind(R.id.main_abl_app_bar)
AppBarLayout mAblAppBar; // 整个可以滑动的AppBar

@Bind(R.id.main_tv_toolbar_title)
TextView mTvToolbarTitle; // 标题栏Title

@Bind(R.id.main_tb_toolbar)
Toolbar mTbToolbar; // 工具栏

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

mTbToolbar.setTitle("");

// AppBar的监听
mAblAppBar.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
@Override
public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
int maxScroll = appBarLayout.getTotalScrollRange();
float percentage = (float) Math.abs(verticalOffset) / (float) maxScroll;
handleAlphaOnTitle(percentage);
handleToolbarTitleVisibility(percentage);
}
});

initParallaxValues(); // 自动滑动效果
}

// 设置自动滑动的动画效果
private void initParallaxValues() {
CollapsingToolbarLayout.LayoutParams petDetailsLp =
(CollapsingToolbarLayout.LayoutParams) mIvPlaceholder.getLayoutParams();

CollapsingToolbarLayout.LayoutParams petBackgroundLp =
(CollapsingToolbarLayout.LayoutParams) mFlTitleContainer.getLayoutParams();

petDetailsLp.setParallaxMultiplier(0.9f);
petBackgroundLp.setParallaxMultiplier(0.3f);

mIvPlaceholder.setLayoutParams(petDetailsLp);
mFlTitleContainer.setLayoutParams(petBackgroundLp);
}

// 处理ToolBar的显示
private void handleToolbarTitleVisibility(float percentage) {
if (percentage >= PERCENTAGE_TO_SHOW_TITLE_AT_TOOLBAR) {
if (!mIsTheTitleVisible) {
startAlphaAnimation(mTvToolbarTitle, ALPHA_ANIMATIONS_DURATION, View.VISIBLE);
mIsTheTitleVisible = true;
}
} else {
if (mIsTheTitleVisible) {
startAlphaAnimation(mTvToolbarTitle, ALPHA_ANIMATIONS_DURATION, View.INVISIBLE);
mIsTheTitleVisible = false;
}
}
}

// 控制Title的显示
private void handleAlphaOnTitle(float percentage) {
if (percentage >= PERCENTAGE_TO_HIDE_TITLE_DETAILS) {
if (mIsTheTitleContainerVisible) {
startAlphaAnimation(mLlTitleContainer, ALPHA_ANIMATIONS_DURATION, View.INVISIBLE);
mIsTheTitleContainerVisible = false;
}
} else {
if (!mIsTheTitleContainerVisible) {
startAlphaAnimation(mLlTitleContainer, ALPHA_ANIMATIONS_DURATION, View.VISIBLE);
mIsTheTitleContainerVisible = true;
}
}
}

// 设置渐变的动画
public static void startAlphaAnimation(View v, long duration, int visibility) {
AlphaAnimation alphaAnimation = (visibility == View.VISIBLE)
? new AlphaAnimation(0f, 1f)
: new AlphaAnimation(1f, 0f);

alphaAnimation.setDuration(duration);
alphaAnimation.setFillAfter(true);
v.startAnimation(alphaAnimation);
}
}

这样联动效果就已经显示出来了, 在AppBar中Toolbar和Title之间的关系, 符合Material的风格, 给用户更多的体验. 既然已经集成到HelloWorld中, 说明Android是极力推荐使用CoordinatorLayout这种风格的.

OK, that's all! Enjot it!