从建议的项目中，我将向您展示一些修改后的方法来获得您想要的行为。
另外我在 github 中添加了我的项目也检查这里
示范
- 创建top_view（在工具栏中可见）和extended_view（在折叠布局中可见）。
- 创建top_view和extended_view通用的自定义类。
- 将
Coordinatelayout行为添加到扩展视图。
- 根据 AppBar 更新两个视图的可见性、位置和大小
onOffsetchangedListener。
TopView 和 ExtendedView 都应该是相同的视图，在折叠时保持在顶部并扩展。
这是代码
header_view.xml（扩展视图）
<?xml version="1.0" encoding="utf-8"?>
<com.md.whatsappgroup_collapseview.HeaderView
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">
<TextView
android:id="@+id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="@dimen/activity_horizontal_margin"
android:layout_marginRight="@dimen/activity_horizontal_margin"
android:layout_alignParentStart="true"
android:layout_alignParentLeft="true"
android:layout_toLeftOf="@+id/edit"
android:layout_toStartOf="@id/edit"
android:gravity="start|center_vertical"
android:ellipsize="end"
android:maxLines="1"
android:textColor="@android:color/white"
android:textSize="@dimen/header_view_start_text_size"
android:textStyle="bold" />
<TextView
android:id="@+id/description"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentLeft="true"
android:layout_toLeftOf="@+id/edit"
android:layout_toStartOf="@id/edit"
android:singleLine="true"
android:gravity="start"
android:textColor="@android:color/white"
android:layout_below="@+id/name"/>
<android.support.v7.widget.AppCompatImageButton
android:id="@+id/edit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_centerVertical="true"
android:background="@android:color/transparent"
app:srcCompat="@drawable/ic_edit_white_24dp"
/>
</com.md.whatsappgroup_collapseview.HeaderView>
header_view_top.xml（顶视图）
<?xml version="1.0" encoding="utf-8"?>
<com.md.whatsappgroup_collapseview.HeaderView
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">
<TextView
android:id="@+id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="@dimen/activity_horizontal_margin"
android:layout_marginRight="@dimen/activity_horizontal_margin"
android:layout_alignParentStart="true"
android:layout_alignParentLeft="true"
android:layout_toLeftOf="@+id/edit"
android:layout_toStartOf="@id/edit"
android:gravity="start"
android:ellipsize="end"
android:maxLines="1"
android:textColor="@android:color/white"
android:textSize="@dimen/header_view_end_text_size"
android:textStyle="bold" />
<TextView
android:id="@+id/description"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentLeft="true"
android:layout_toLeftOf="@+id/edit"
android:layout_toStartOf="@id/edit"
android:singleLine="true"
android:gravity="start"
android:textColor="@android:color/white"
android:layout_below="@+id/name"/>
<android.support.v7.widget.AppCompatImageButton
android:id="@+id/edit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_marginRight="8dp"
android:layout_marginEnd="8dp"
android:background="@android:color/transparent"
app:srcCompat="@drawable/ic_edit_white_24dp"
/>
</com.md.whatsappgroup_collapseview.HeaderView>
activity_main.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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<android.support.design.widget.AppBarLayout
android:id="@+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/AppTheme.AppBarOverlay">
<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="400dp"
android:fitsSystemWindows="true"
app:scrimVisibleHeightTrigger="60dp"
app:scrimAnimationDuration="300"
app:statusBarScrim="@android:color/transparent"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<ImageView
android:id="@+id/image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
android:src="@drawable/photo"
android:contentDescription="@string/thumbnail"
app:layout_collapseMode="parallax" />
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@android:color/transparent"
android:fitsSystemWindows="true"
app:contentInsetStartWithNavigation="0dp"
app:layout_collapseMode="pin"
app:popupTheme="@style/AppTheme.PopupOverlay">
<include
android:id="@+id/toolbar_header_view"
layout="@layout/header_view_top"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:visibility="gone" />
</android.support.v7.widget.Toolbar>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<include
android:id="@+id/float_header_view"
layout="@layout/header_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_above="@+id/scrollView"
app:layout_behavior="com.md.whatsappgroup_collapseview.HeaderBehaviour" />
<android.support.v4.widget.NestedScrollView
android:id="@+id/scrollView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipToPadding="false"
app:layout_behavior="@string/appbar_scrolling_view_behavior">
<include layout="@layout/content_main" />
</android.support.v4.widget.NestedScrollView>
</android.support.design.widget.CoordinatorLayout>
HeaderView.Java（自定义类）
import android.annotation.TargetApi;
import android.content.Context;
import android.os.Build;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.widget.RelativeLayout;
import android.widget.TextView;
import butterknife.BindView;
import butterknife.ButterKnife;
public class HeaderView extends RelativeLayout {
@BindView(R.id.name)
TextView tvName;
@BindView(R.id.description)
TextView tvDescription;
public HeaderView(Context context) {
super(context);
}
public HeaderView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public HeaderView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public HeaderView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
@Override
protected void onFinishInflate() {
super.onFinishInflate();
ButterKnife.bind(this);
}
public void bindTo(String name, String lastSeen) {
this.tvName.setText(name);
this.tvDescription.setText(lastSeen);
}
public void setTextSize(float size) {
tvName.setTextSize(TypedValue.COMPLEX_UNIT_PX, size);
}
}
Header_behaviour.java
public class HeaderBehaviour extends CoordinatorLayout.Behavior<HeaderView> {
private Context mContext;
private int mStartMarginLeft;
private int mEndMarginLeft;
private int mMarginRight;
private int mStartMarginBottom;
private float mTitleStartSize;
private float mTitleEndSize;
private boolean isHide;
public HeaderBehaviour(Context context, AttributeSet attrs) {
super(context, attrs);
mContext = context;
}
public HeaderBehaviour(Context context, AttributeSet attrs, Context mContext) {
super(context, attrs);
this.mContext = mContext;
}
public static int getToolbarHeight(Context context) {
int result = 0;
TypedValue tv = new TypedValue();
if (context.getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true)) {
result = TypedValue.complexToDimensionPixelSize(tv.data, context.getResources().getDisplayMetrics());
}
return result;
}
@Override
public boolean layoutDependsOn(@NonNull CoordinatorLayout parent, @NonNull HeaderView child, @NonNull View dependency) {
return dependency instanceof AppBarLayout;
}
@Override
public boolean onDependentViewChanged(@NonNull CoordinatorLayout parent, @NonNull HeaderView child, @NonNull View dependency) {
shouldInitProperties();
int maxScroll = ((AppBarLayout) dependency).getTotalScrollRange();
float percentage = Math.abs(dependency.getY()) / (float) maxScroll;
float childPosition = dependency.getHeight()
+ dependency.getY()
- child.getHeight()
- (getToolbarHeight(mContext) - child.getHeight()) * percentage / 2;
childPosition = childPosition - mStartMarginBottom * (1f - percentage);
CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams) child.getLayoutParams();
if (Math.abs(dependency.getY()) >= maxScroll / 2) {
float layoutPercentage = (Math.abs(dependency.getY()) - (maxScroll / 2)) / Math.abs(maxScroll / 2);
lp.leftMargin = (int) (layoutPercentage * mEndMarginLeft) + mStartMarginLeft;
lp.rightMargin = (int) (layoutPercentage * mEndMarginLeft) + mStartMarginLeft;
child.setTextSize(getTranslationOffset(mTitleStartSize, mTitleEndSize, layoutPercentage));
} else {
lp.leftMargin = mStartMarginLeft;
lp.rightMargin = mStartMarginLeft;
}
child.setLayoutParams(lp);
child.setY(childPosition);
if (isHide && percentage < 1) {
child.setVisibility(View.VISIBLE);
isHide = false;
} else if (!isHide && percentage == 1) {
child.setVisibility(View.GONE);
isHide = true;
}
return true;
}
private float getTranslationOffset(float expandedOffset, float collapsedOffset, float ratio) {
return expandedOffset + ratio * (collapsedOffset - expandedOffset);
}
private void shouldInitProperties() {
if (mStartMarginLeft == 0) {
mStartMarginLeft = mContext.getResources().getDimensionPixelOffset(R.dimen.header_view_start_margin_left);
}
if (mEndMarginLeft == 0) {
mEndMarginLeft = mContext.getResources().getDimensionPixelOffset(R.dimen.header_view_end_margin_left);
}
if (mStartMarginBottom == 0) {
mStartMarginBottom = mContext.getResources().getDimensionPixelOffset(R.dimen.header_view_start_margin_bottom);
}
if (mMarginRight == 0) {
mMarginRight = mContext.getResources().getDimensionPixelOffset(R.dimen.header_view_end_margin_right);
}
if (mTitleStartSize == 0) {
mTitleEndSize = mContext.getResources().getDimensionPixelSize(R.dimen.header_view_end_text_size);
}
if (mTitleStartSize == 0) {
mTitleStartSize = mContext.getResources().getDimensionPixelSize(R.dimen.header_view_start_text_size);
}
}
}
Mainactivity.java
public class MainActivity extends AppCompatActivity implements AppBarLayout.OnOffsetChangedListener{
@BindView(R.id.toolbar_header_view)
protected HeaderView toolbarHeaderView;
@BindView(R.id.float_header_view)
protected HeaderView floatHeaderView;
@BindView(R.id.appbar)
protected AppBarLayout appBarLayout;
@BindView(R.id.toolbar)
protected Toolbar toolbar;
@BindView(R.id.collapsing_toolbar)
protected CollapsingToolbarLayout collapsingToolbarLayout;
private boolean isHideToolbarView = false;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ButterKnife.bind(this);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowTitleEnabled(false);
initUi();
/*Remove no need to change custom scrim colour */
Bitmap icon = BitmapFactory.decodeResource(getResources(), R.drawable.photo);
int color = getDominantColor(icon);
collapsingToolbarLayout.setContentScrimColor(color);
collapsingToolbarLayout.setStatusBarScrimColor(color);
if (Build.VERSION.SDK_INT >= 21) {
getWindow().setStatusBarColor(darker(color,0.8f));
}
/*Remove no need to change custom scrim colour*/
}
public static int darker (int color, float factor) {
int a = Color.alpha( color );
int r = Color.red( color );
int g = Color.green( color );
int b = Color.blue( color );
return Color.argb( a,
Math.max( (int)(r * factor), 0 ),
Math.max( (int)(g * factor), 0 ),
Math.max( (int)(b * factor), 0 ) );
}
public static int getDominantColor(Bitmap bitmap) {
Bitmap newBitmap = Bitmap.createScaledBitmap(bitmap, 1, 1, true);
final int color = newBitmap.getPixel(0, 0);
newBitmap.recycle();
return color;
}
private void initUi() {
appBarLayout.addOnOffsetChangedListener(this);
toolbarHeaderView.bindTo("Group Name", "Created by Developer");
floatHeaderView.bindTo("Group Name", "Created by Developer");
}
@Override
public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
int maxScroll = appBarLayout.getTotalScrollRange();
float percentage = (float) Math.abs(verticalOffset) / (float) maxScroll;
if (percentage == 1f && isHideToolbarView) {
toolbarHeaderView.setVisibility(View.VISIBLE);
isHideToolbarView = !isHideToolbarView;
} else if (percentage < 1f && !isHideToolbarView) {
toolbarHeaderView.setVisibility(View.GONE);
isHideToolbarView = !isHideToolbarView;
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_person_add) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
输出
希望对你有帮助。！
