How to use setEmptyView in Android
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Correct use of setEmptyView in Android ListView
If emptyView and listview already belong to the same parent in the layout, the code to set EmptyView is as follows
Private void setEmptyView () {emptyTv.setText (getString (R.string.txt_no_data_refreshable)); mList.setEmptyView (empty);}
If there is no data, run, everything is normal.
After we execute a sentence of code,
MList.setVisibility (View.VISIBLE)
We found that emptyView can't see it. Strange!
Let's take a look at listview's setEmptyView code.
Public void setEmptyView (View emptyView) {mEmptyView = emptyView; / / If not explicitly specified this view is important for accessibility. If (emptyView! = null & & emptyView.getImportantForAccessibility () = IMPORTANT_FOR_ACCESSIBILITY_AUTO) {emptyView.setImportantForAccessibility (IMPORTANT_FOR_ACCESSIBILITY_YES);} final T adapter = getAdapter (); final boolean empty = ((adapter = = null) | | adapter.isEmpty ()); updateEmptyStatus (empty);}
It focuses on the source code of updateEmptyStatus.
Private void updateEmptyStatus (boolean empty) {if (isInFilterMode ()) {empty = false;} if (empty) {if (mEmptyView! = null) {mEmptyView.setVisibility (View.VISIBLE); setVisibility (View.GONE);} else {setVisibility (View.VISIBLE);} if (mDataChanged) {this.onLayout (false, mLeft, mTop, mRight, mBottom) }} else {if (mEmptyView! = null) mEmptyView.setVisibility (View.GONE); setVisibility (View.VISIBLE);}}
We found that to control the display of emptyView is to hide listview, the two try to hide the display from each other to achieve the effect, and the updateEmptyStatus method will only be executed when listview's setEmptyView, so when you execute mList.setVisibility (View.VISIBLE), listview is set to be visible, it overrides emptyView, so you can't see it, if you want to show emptyView, execute the setEmptyView method again.
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