如何在 TabLayout 中获取 Tab 的视图？
How do I get the view of a Tab in a TabLayout?
我想在 TabLayout 中找到 Tab 的视图，以便我可以将它传递给另一个函数。我不确定如何去寻找风景。
myTabLayout.getTabAt(0).getCustomView() returns 空。
如何获取视图？
TabLayout tabLayout = (TabLayout) rootView.findViewById(R.id.tab_layout_main);
tabLayout.addTab(tabLayout.newTab().setText("Page1"));
tabLayout.addTab(tabLayout.newTab().setText("Page2"));
viewPager = (ViewPager) rootView.findViewById(R.id.pager_main);
pagerAdapter = new MyPagerAdapter(getActivity(), getChildFragmentManager(), tabLayout.getTabCount());
viewPager.setAdapter(pagerAdapter);
它 returns null 因为您一开始就没有使用任何自定义视图。它 return 只有在您使用它时才是自定义视图。要使用自定义视图，您的代码应该是这样的。
tabLayout.addTab(tabLayout.newTab().setCustomView(R.layout.custom_view).setText("Page1"));
如果您使用以上行然后尝试调用 myTabLayout.getTabAt(0).getCustomView()，它会 return 您设置的视图。
我最终使用以下方法获取选项卡视图。我只是不确定它是否是最佳实践，或者它在所有 Android 版本中是否可靠：
mainTab = ((ViewGroup) tabLayout.getChildAt(0)).getChildAt(desiredPosition);
查看源代码我们可以看到 tabLayout.getChildAt(0) returns SlidingTabStrip 是一个内部 class 扩展 LinearLayout 来保存选项卡视图。然后，您可以使用 .getChildAt(desiredPosition) 访问选项卡视图。请注意，使用 getChildAt() 时不会检查边界，因此请确保调用正确的索引并检查 null returns。
TabLayout tabLayout = .... (findview or code creation )
/** get selected tab index */
int selectedTabPosition = tabLayout.getSelectedTabPosition();
/** get tab for selected index or if u want any other tab set desired index */
TabLayout.Tab tabAt = tabLayout.getTabAt(selectedTabPosition);
/** get view - but first u need set custom view on tabl via Tab.setCustomView(View) */
View tabView = tabAt.getCustomView():
提示：
- 如果您使用
ViewPager 填充 TabLayout，请首先检查视图是否已布局 :)。如果未为 ViewPager 设置 onLayoutChangedListener，则使用寻呼机设置！
Tab 如果你想使用反射，来源 :D
/**
* A tab in this layout. Instances can be created via {@link #newTab()}.
*/
public static final class Tab {
/**
* An invalid position for a tab.
*
* @see #getPosition()
*/
public static final int INVALID_POSITION = -1;
private Object mTag;
private Drawable mIcon;
private CharSequence mText;
private CharSequence mContentDesc;
private int mPosition = INVALID_POSITION;
private View mCustomView;
private final TabLayout mParent;
Tab(TabLayout parent) {
mParent = parent;
}
/**
* @return This Tab's tag object.
*/
@Nullable
public Object getTag() {
return mTag;
}
/**
* Give this Tab an arbitrary object to hold for later use.
*
* @param tag Object to store
* @return The current instance for call chaining
*/
@NonNull
public Tab setTag(@Nullable Object tag) {
mTag = tag;
return this;
}
/**
* Returns the custom view used for this tab.
*
* @see #setCustomView(View)
* @see #setCustomView(int)
*/
@Nullable
public View getCustomView() {
return mCustomView;
}
/**
* Set a custom view to be used for this tab.
* <p>
* If the provided view contains a {@link TextView} with an ID of
* {@link android.R.id#text1} then that will be updated with the value given
* to {@link #setText(CharSequence)}. Similarly, if this layout contains an
* {@link ImageView} with ID {@link android.R.id#icon} then it will be updated with
* the value given to {@link #setIcon(Drawable)}.
* </p>
*
* @param view Custom view to be used as a tab.
* @return The current instance for call chaining
*/
@NonNull
public Tab setCustomView(@Nullable View view) {
mCustomView = view;
if (mPosition >= 0) {
mParent.updateTab(mPosition);
}
return this;
}
/**
* Set a custom view to be used for this tab.
* <p>
* If the inflated layout contains a {@link TextView} with an ID of
* {@link android.R.id#text1} then that will be updated with the value given
* to {@link #setText(CharSequence)}. Similarly, if this layout contains an
* {@link ImageView} with ID {@link android.R.id#icon} then it will be updated with
* the value given to {@link #setIcon(Drawable)}.
* </p>
*
* @param layoutResId A layout resource to inflate and use as a custom tab view
* @return The current instance for call chaining
*/
@NonNull
public Tab setCustomView(@LayoutRes int layoutResId) {
return setCustomView(
LayoutInflater.from(mParent.getContext()).inflate(layoutResId, null));
}
/**
* Return the icon associated with this tab.
*
* @return The tab's icon
*/
@Nullable
public Drawable getIcon() {
return mIcon;
}
/**
* Return the current position of this tab in the action bar.
*
* @return Current position, or {@link #INVALID_POSITION} if this tab is not currently in
* the action bar.
*/
public int getPosition() {
return mPosition;
}
void setPosition(int position) {
mPosition = position;
}
/**
* Return the text of this tab.
*
* @return The tab's text
*/
@Nullable
public CharSequence getText() {
return mText;
}
/**
* Set the icon displayed on this tab.
*
* @param icon The drawable to use as an icon
* @return The current instance for call chaining
*/
@NonNull
public Tab setIcon(@Nullable Drawable icon) {
mIcon = icon;
if (mPosition >= 0) {
mParent.updateTab(mPosition);
}
return this;
}
/**
* Set the icon displayed on this tab.
*
* @param resId A resource ID referring to the icon that should be displayed
* @return The current instance for call chaining
*/
@NonNull
public Tab setIcon(@DrawableRes int resId) {
return setIcon(TintManager.getDrawable(mParent.getContext(), resId));
}
/**
* Set the text displayed on this tab. Text may be truncated if there is not room to display
* the entire string.
*
* @param text The text to display
* @return The current instance for call chaining
*/
@NonNull
public Tab setText(@Nullable CharSequence text) {
mText = text;
if (mPosition >= 0) {
mParent.updateTab(mPosition);
}
return this;
}
/**
* Set the text displayed on this tab. Text may be truncated if there is not room to display
* the entire string.
*
* @param resId A resource ID referring to the text that should be displayed
* @return The current instance for call chaining
*/
@NonNull
public Tab setText(@StringRes int resId) {
return setText(mParent.getResources().getText(resId));
}
/**
* Select this tab. Only valid if the tab has been added to the action bar.
*/
public void select() {
mParent.selectTab(this);
}
/**
* Returns true if this tab is currently selected.
*/
public boolean isSelected() {
return mParent.getSelectedTabPosition() == mPosition;
}
/**
* Set a description of this tab's content for use in accessibility support. If no content
* description is provided the title will be used.
*
* @param resId A resource ID referring to the description text
* @return The current instance for call chaining
* @see #setContentDescription(CharSequence)
* @see #getContentDescription()
*/
@NonNull
public Tab setContentDescription(@StringRes int resId) {
return setContentDescription(mParent.getResources().getText(resId));
}
/**
* Set a description of this tab's content for use in accessibility support. If no content
* description is provided the title will be used.
*
* @param contentDesc Description of this tab's content
* @return The current instance for call chaining
* @see #setContentDescription(int)
* @see #getContentDescription()
*/
@NonNull
public Tab setContentDescription(@Nullable CharSequence contentDesc) {
mContentDesc = contentDesc;
if (mPosition >= 0) {
mParent.updateTab(mPosition);
}
return this;
}
/**
* Gets a brief description of this tab's content for use in accessibility support.
*
* @return Description of this tab's content
* @see #setContentDescription(CharSequence)
* @see #setContentDescription(int)
*/
@Nullable
public CharSequence getContentDescription() {
return mContentDesc;
}
}
或者你可以直接挂钩（通过反射）：
private final SlidingTabStrip mTabStrip;
或者您可以自行决定复制源代码并更改方法和字段。
回答以备将来参考。
tabLayout.getTabAt(tabIndex).view
例子-
获取 tabLayout 中第一个选项卡的视图。使用 tabLayout.getTabAt(0).view
我想在 TabLayout 中找到 Tab 的视图，以便我可以将它传递给另一个函数。我不确定如何去寻找风景。
myTabLayout.getTabAt(0).getCustomView() returns 空。
如何获取视图？
TabLayout tabLayout = (TabLayout) rootView.findViewById(R.id.tab_layout_main);
tabLayout.addTab(tabLayout.newTab().setText("Page1"));
tabLayout.addTab(tabLayout.newTab().setText("Page2"));
viewPager = (ViewPager) rootView.findViewById(R.id.pager_main);
pagerAdapter = new MyPagerAdapter(getActivity(), getChildFragmentManager(), tabLayout.getTabCount());
viewPager.setAdapter(pagerAdapter);
它 returns null 因为您一开始就没有使用任何自定义视图。它 return 只有在您使用它时才是自定义视图。要使用自定义视图，您的代码应该是这样的。
tabLayout.addTab(tabLayout.newTab().setCustomView(R.layout.custom_view).setText("Page1"));
如果您使用以上行然后尝试调用 myTabLayout.getTabAt(0).getCustomView()，它会 return 您设置的视图。
我最终使用以下方法获取选项卡视图。我只是不确定它是否是最佳实践，或者它在所有 Android 版本中是否可靠：
mainTab = ((ViewGroup) tabLayout.getChildAt(0)).getChildAt(desiredPosition);
查看源代码我们可以看到 tabLayout.getChildAt(0) returns SlidingTabStrip 是一个内部 class 扩展 LinearLayout 来保存选项卡视图。然后，您可以使用 .getChildAt(desiredPosition) 访问选项卡视图。请注意，使用 getChildAt() 时不会检查边界，因此请确保调用正确的索引并检查 null returns。
TabLayout tabLayout = .... (findview or code creation )
/** get selected tab index */
int selectedTabPosition = tabLayout.getSelectedTabPosition();
/** get tab for selected index or if u want any other tab set desired index */
TabLayout.Tab tabAt = tabLayout.getTabAt(selectedTabPosition);
/** get view - but first u need set custom view on tabl via Tab.setCustomView(View) */
View tabView = tabAt.getCustomView():
提示：
- 如果您使用
ViewPager填充TabLayout，请首先检查视图是否已布局 :)。如果未为ViewPager设置onLayoutChangedListener，则使用寻呼机设置！
Tab 如果你想使用反射，来源 :D
/**
* A tab in this layout. Instances can be created via {@link #newTab()}.
*/
public static final class Tab {
/**
* An invalid position for a tab.
*
* @see #getPosition()
*/
public static final int INVALID_POSITION = -1;
private Object mTag;
private Drawable mIcon;
private CharSequence mText;
private CharSequence mContentDesc;
private int mPosition = INVALID_POSITION;
private View mCustomView;
private final TabLayout mParent;
Tab(TabLayout parent) {
mParent = parent;
}
/**
* @return This Tab's tag object.
*/
@Nullable
public Object getTag() {
return mTag;
}
/**
* Give this Tab an arbitrary object to hold for later use.
*
* @param tag Object to store
* @return The current instance for call chaining
*/
@NonNull
public Tab setTag(@Nullable Object tag) {
mTag = tag;
return this;
}
/**
* Returns the custom view used for this tab.
*
* @see #setCustomView(View)
* @see #setCustomView(int)
*/
@Nullable
public View getCustomView() {
return mCustomView;
}
/**
* Set a custom view to be used for this tab.
* <p>
* If the provided view contains a {@link TextView} with an ID of
* {@link android.R.id#text1} then that will be updated with the value given
* to {@link #setText(CharSequence)}. Similarly, if this layout contains an
* {@link ImageView} with ID {@link android.R.id#icon} then it will be updated with
* the value given to {@link #setIcon(Drawable)}.
* </p>
*
* @param view Custom view to be used as a tab.
* @return The current instance for call chaining
*/
@NonNull
public Tab setCustomView(@Nullable View view) {
mCustomView = view;
if (mPosition >= 0) {
mParent.updateTab(mPosition);
}
return this;
}
/**
* Set a custom view to be used for this tab.
* <p>
* If the inflated layout contains a {@link TextView} with an ID of
* {@link android.R.id#text1} then that will be updated with the value given
* to {@link #setText(CharSequence)}. Similarly, if this layout contains an
* {@link ImageView} with ID {@link android.R.id#icon} then it will be updated with
* the value given to {@link #setIcon(Drawable)}.
* </p>
*
* @param layoutResId A layout resource to inflate and use as a custom tab view
* @return The current instance for call chaining
*/
@NonNull
public Tab setCustomView(@LayoutRes int layoutResId) {
return setCustomView(
LayoutInflater.from(mParent.getContext()).inflate(layoutResId, null));
}
/**
* Return the icon associated with this tab.
*
* @return The tab's icon
*/
@Nullable
public Drawable getIcon() {
return mIcon;
}
/**
* Return the current position of this tab in the action bar.
*
* @return Current position, or {@link #INVALID_POSITION} if this tab is not currently in
* the action bar.
*/
public int getPosition() {
return mPosition;
}
void setPosition(int position) {
mPosition = position;
}
/**
* Return the text of this tab.
*
* @return The tab's text
*/
@Nullable
public CharSequence getText() {
return mText;
}
/**
* Set the icon displayed on this tab.
*
* @param icon The drawable to use as an icon
* @return The current instance for call chaining
*/
@NonNull
public Tab setIcon(@Nullable Drawable icon) {
mIcon = icon;
if (mPosition >= 0) {
mParent.updateTab(mPosition);
}
return this;
}
/**
* Set the icon displayed on this tab.
*
* @param resId A resource ID referring to the icon that should be displayed
* @return The current instance for call chaining
*/
@NonNull
public Tab setIcon(@DrawableRes int resId) {
return setIcon(TintManager.getDrawable(mParent.getContext(), resId));
}
/**
* Set the text displayed on this tab. Text may be truncated if there is not room to display
* the entire string.
*
* @param text The text to display
* @return The current instance for call chaining
*/
@NonNull
public Tab setText(@Nullable CharSequence text) {
mText = text;
if (mPosition >= 0) {
mParent.updateTab(mPosition);
}
return this;
}
/**
* Set the text displayed on this tab. Text may be truncated if there is not room to display
* the entire string.
*
* @param resId A resource ID referring to the text that should be displayed
* @return The current instance for call chaining
*/
@NonNull
public Tab setText(@StringRes int resId) {
return setText(mParent.getResources().getText(resId));
}
/**
* Select this tab. Only valid if the tab has been added to the action bar.
*/
public void select() {
mParent.selectTab(this);
}
/**
* Returns true if this tab is currently selected.
*/
public boolean isSelected() {
return mParent.getSelectedTabPosition() == mPosition;
}
/**
* Set a description of this tab's content for use in accessibility support. If no content
* description is provided the title will be used.
*
* @param resId A resource ID referring to the description text
* @return The current instance for call chaining
* @see #setContentDescription(CharSequence)
* @see #getContentDescription()
*/
@NonNull
public Tab setContentDescription(@StringRes int resId) {
return setContentDescription(mParent.getResources().getText(resId));
}
/**
* Set a description of this tab's content for use in accessibility support. If no content
* description is provided the title will be used.
*
* @param contentDesc Description of this tab's content
* @return The current instance for call chaining
* @see #setContentDescription(int)
* @see #getContentDescription()
*/
@NonNull
public Tab setContentDescription(@Nullable CharSequence contentDesc) {
mContentDesc = contentDesc;
if (mPosition >= 0) {
mParent.updateTab(mPosition);
}
return this;
}
/**
* Gets a brief description of this tab's content for use in accessibility support.
*
* @return Description of this tab's content
* @see #setContentDescription(CharSequence)
* @see #setContentDescription(int)
*/
@Nullable
public CharSequence getContentDescription() {
return mContentDesc;
}
}
或者你可以直接挂钩（通过反射）：
private final SlidingTabStrip mTabStrip;
或者您可以自行决定复制源代码并更改方法和字段。
回答以备将来参考。
tabLayout.getTabAt(tabIndex).view
例子- 获取 tabLayout 中第一个选项卡的视图。使用 tabLayout.getTabAt(0).view