我CollapsingToolBarLayout
与AppBarLayout
和一起使用CoordinatorLayout
,它们一起工作正常。Toolbar
向上滚动时,我将其设置为固定,我想知道在CollapsingToolBarLayout
折叠时是否有办法更改工具栏的标题文本。
总结一下,在滚动和展开时我想要两个不同的标题。
谢谢大家
我CollapsingToolBarLayout
与AppBarLayout
和一起使用CoordinatorLayout
,它们一起工作正常。Toolbar
向上滚动时,我将其设置为固定,我想知道在CollapsingToolBarLayout
折叠时是否有办法更改工具栏的标题文本。
总结一下,在滚动和展开时我想要两个不同的标题。
谢谢大家
Answers:
我分享了基于@Frodio Beggins和@Nifhel代码的完整实现:
public abstract class AppBarStateChangeListener implements AppBarLayout.OnOffsetChangedListener {
public enum State {
EXPANDED,
COLLAPSED,
IDLE
}
private State mCurrentState = State.IDLE;
@Override
public final void onOffsetChanged(AppBarLayout appBarLayout, int i) {
if (i == 0) {
if (mCurrentState != State.EXPANDED) {
onStateChanged(appBarLayout, State.EXPANDED);
}
mCurrentState = State.EXPANDED;
} else if (Math.abs(i) >= appBarLayout.getTotalScrollRange()) {
if (mCurrentState != State.COLLAPSED) {
onStateChanged(appBarLayout, State.COLLAPSED);
}
mCurrentState = State.COLLAPSED;
} else {
if (mCurrentState != State.IDLE) {
onStateChanged(appBarLayout, State.IDLE);
}
mCurrentState = State.IDLE;
}
}
public abstract void onStateChanged(AppBarLayout appBarLayout, State state);
}
然后您可以使用它:
appBarLayout.addOnOffsetChangedListener(new AppBarStateChangeListener() {
@Override
public void onStateChanged(AppBarLayout appBarLayout, State state) {
Log.d("STATE", state.name());
}
});
该解决方案非常适合我检测AppBarLayout
折叠或展开。
appBarLayout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
@Override
public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
if (Math.abs(verticalOffset)-appBarLayout.getTotalScrollRange() == 0)
{
// Collapsed
}
else
{
//Expanded
}
}
});
使用addOnOffsetChangedListener
上AppBarLayout
。
勾OnOffsetChangedListener
上你的AppBarLayout
。当verticalOffset
到达的Toolbar
高度小于或等于0时,表示CollapsingToolbarLayout已折叠,否则将展开或扩展。
mAppBarLayout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
@Override
public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
if(verticalOffset == 0 || verticalOffset <= mToolbar.getHeight() && !mToolbar.getTitle().equals(mCollapsedTitle)){
mCollapsingToolbar.setTitle(mCollapsedTitle);
}else if(!mToolbar.getTitle().equals(mExpandedTitle)){
mCollapsingToolbar.setTitle(mExpandedTitle);
}
}
});
appBarLayout.getVerticalOffset()
方法在哪里,则可以调用appBarLayout.getY()
来检索回调中使用的相同值。
appBarLayout.getY()
,可能是verticalOffset = appBarLayout.getY() + statusBarHeight
这段代码对我有用
mAppBarLayout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
@Override
public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
if (verticalOffset == -mCollapsingToolbarLayout.getHeight() + mToolbar.getHeight()) {
//toolbar is collapsed here
//write your code here
}
}
});
private enum State {
EXPANDED,
COLLAPSED,
IDLE
}
private void initViews() {
final String TAG = "AppBarTest";
final AppBarLayout mAppBarLayout = findViewById(R.id.appbar);
mAppBarLayout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
private State state;
@Override
public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
if (verticalOffset == 0) {
if (state != State.EXPANDED) {
Log.d(TAG,"Expanded");
}
state = State.EXPANDED;
} else if (Math.abs(verticalOffset) >= appBarLayout.getTotalScrollRange()) {
if (state != State.COLLAPSED) {
Log.d(TAG,"Collapsed");
}
state = State.COLLAPSED;
} else {
if (state != State.IDLE) {
Log.d(TAG,"Idle");
}
state = State.IDLE;
}
}
});
}
您可以使用以下方法获取collapsingToolBar alpha百分比:
appbarLayout.addOnOffsetChangedListener( new AppBarLayout.OnOffsetChangedListener() {
@Override
public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
float percentage = ((float)Math.abs(verticalOffset)/appBarLayout.getTotalScrollRange());
fadedView.setAlpha(percentage);
});
供参考:链接
verticalOffset
像素距离。
这是Kotlin解决方案。一个添加OnOffsetChangedListener
到AppBarLayout
。
方法A:
添加AppBarStateChangeListener.kt
到您的项目:
import com.google.android.material.appbar.AppBarLayout
import kotlin.math.abs
abstract class AppBarStateChangeListener : AppBarLayout.OnOffsetChangedListener {
enum class State {
EXPANDED, COLLAPSED, IDLE
}
private var mCurrentState = State.IDLE
override fun onOffsetChanged(appBarLayout: AppBarLayout, i: Int) {
if (i == 0 && mCurrentState != State.EXPANDED) {
onStateChanged(appBarLayout, State.EXPANDED)
mCurrentState = State.EXPANDED
}
else if (abs(i) >= appBarLayout.totalScrollRange && mCurrentState != State.COLLAPSED) {
onStateChanged(appBarLayout, State.COLLAPSED)
mCurrentState = State.COLLAPSED
}
else if (mCurrentState != State.IDLE) {
onStateChanged(appBarLayout, State.IDLE)
mCurrentState = State.IDLE
}
}
abstract fun onStateChanged(
appBarLayout: AppBarLayout?,
state: State?
)
}
将侦听器添加到您的appBarLayout
:
appBarLayout.addOnOffsetChangedListener(object: AppBarStateChangeListener() {
override fun onStateChanged(appBarLayout: AppBarLayout?, state: State?) {
Log.d("State", state.name)
when(state) {
State.COLLAPSED -> { /* Do something */ }
State.EXPANDED -> { /* Do something */ }
State.IDLE -> { /* Do something */ }
}
}
}
)
方法B:
appBarLayout.addOnOffsetChangedListener(AppBarLayout.OnOffsetChangedListener { appBarLayout, verticalOffset ->
if (abs(verticalOffset) - appBarLayout.totalScrollRange == 0) {
// Collapsed
} else if (verticalOffset == 0) {
// Expanded
} else {
// Idle
}
}
)
此解决方案为我工作:
@Override
public void onOffsetChanged(AppBarLayout appBarLayout, int i) {
if (i == 0) {
if (onStateChangeListener != null && state != State.EXPANDED) {
onStateChangeListener.onStateChange(State.EXPANDED);
}
state = State.EXPANDED;
} else if (Math.abs(i) >= appBarLayout.getTotalScrollRange()) {
if (onStateChangeListener != null && state != State.COLLAPSED) {
onStateChangeListener.onStateChange(State.COLLAPSED);
}
state = State.COLLAPSED;
} else {
if (onStateChangeListener != null && state != State.IDLE) {
onStateChangeListener.onStateChange(State.IDLE);
}
state = State.IDLE;
}
}
在AppBarLayout上使用addOnOffsetChangedListener。
该代码对我来说是完美的。您可以使用百分比刻度
@Override
public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
double percentage = (double) Math.abs(verticalOffset) / collapsingToolbar.getHeight();
if (percentage > 0.8) {
collapsingToolbar.setTitle("Collapsed");
} else {
collapsingToolbar.setTitle("Expanded");
}
}
我的工具栏偏移值在合拢时会在展开= 0时得到-582,因此我可以通过在Toast中设置offsetvalue来找到值,并相应地更改代码。
mAppBarLayout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
@Override
public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
if(verticalOffset == -582) {
Toast.makeText(MainActivity.this, "collaped" + verticalOffset, Toast.LENGTH_SHORT).show();
mCollapsingToolbarLayout.setTitle("Collapsed");
}else if(verticalOffset == 0){
Toast.makeText(MainActivity.this, "expanded" + verticalOffset, Toast.LENGTH_SHORT).show();
mCollapsingToolbarLayout.setTitle("expanded");
}
}
});