Android 如何修复滚动时滚动标题的闪烁?
我需要实现ListView的标题,当用户向下滚动ListView时隐藏,当用户向上滚动ListView时再次显示。但我遇到了一个问题:当我慢慢向下滚动ListView时,标题会闪烁。我知道这是因为ListView改变了大小。但如何修复呢 以下是代码:Android 如何修复滚动时滚动标题的闪烁?,android,android-listview,Android,Android Listview,我需要实现ListView的标题,当用户向下滚动ListView时隐藏,当用户向上滚动ListView时再次显示。但我遇到了一个问题:当我慢慢向下滚动ListView时,标题会闪烁。我知道这是因为ListView改变了大小。但如何修复呢 以下是代码: public class MainActivity extends ActionBarActivity implements AbsListView.OnScrollListener { private static final int
public class MainActivity extends ActionBarActivity implements AbsListView.OnScrollListener {
private static final int LIST_DATA_COUNT = 100;
private View mHeader;
private int mLastFirstVisibleItem;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mHeader = findViewById(R.id.textView);
String[] listData = new String[LIST_DATA_COUNT];
for (int i=0;i<LIST_DATA_COUNT;i++) {
listData[i]= String.valueOf(i);
}
ListView listView = (ListView) findViewById(R.id.listView);
listView.setAdapter(new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, android.R.id.text1, listData));
listView.setOnScrollListener(this);
}
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
if (firstVisibleItem<mLastFirstVisibleItem) {
Log.d("tag", "up");
mHeader.setVisibility(View.VISIBLE);
} else if (firstVisibleItem>mLastFirstVisibleItem) {
Log.d("tag", "down");
mHeader.setVisibility(View.GONE);
}
mLastFirstVisibleItem = firstVisibleItem;
}
}
您可以将标题显示为覆盖。这将阻止ListView调整大小。对于第一个版本,请尝试更改ListView和TextView顺序
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<ListView
android:id="@+id/listView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@id/textView"/>
<TextView
android:layout_width="match_parent"
android:layout_height="80dp"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Header"
android:gravity="center"
android:id="@+id/textView"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"/>
</RelativeLayout>
尝试对
列表视图使用触摸监听器
。这可能对你有用
listView.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
int action = event.getAction();
if (action == MotionEvent.ACTION_DOWN) {
startY = event.getY();//declare as global variable
return true;
} else if (action == MotionEvent.ACTION_MOVE) {
float y = event.getY();
if(startY-y<-60){
Log.w(TAG, "scroll down");
mHeader.setVisibility(View.VISIBLE);
}else if(startY-y>60){
Log.w(TAG, "scroll up");
mHeader.setVisibility(View.GONE);
}
}
return false;
}
});
listView.setOnTouchListener(新视图.OnTouchListener(){
@凌驾
公共布尔onTouch(视图v,运动事件){
int action=event.getAction();
if(action==MotionEvent.action\u DOWN){
startY=event.getY();//声明为全局变量
返回true;
}else if(action==MotionEvent.action\u MOVE){
float y=event.getY();
如果(startY-y60){
Log.w(标记“向上滚动”);
mHeader.setVisibility(View.GONE);
}
}
返回false;
}
});
否,这不是所需的。标题必须具有固定位置,并且在用户向下滚动ListView时必须隐藏。所以ListView总是会调整大小,这种行为是正常的,但这是不一样的。我的标题也必须显示在列表的中间。您可以运行我的代码来了解它是如何工作的。@BArtWell请尝试我更新的答案,并告诉我它是否适合您?是的,它工作得很好。但是返回true代码>是不需要的。非常感谢。
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<ListView
android:id="@+id/listView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@id/textView"/>
<TextView
android:layout_width="match_parent"
android:layout_height="80dp"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Header"
android:gravity="center"
android:id="@+id/textView"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"/>
</RelativeLayout>
listView.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
int action = event.getAction();
if (action == MotionEvent.ACTION_DOWN) {
startY = event.getY();//declare as global variable
return true;
} else if (action == MotionEvent.ACTION_MOVE) {
float y = event.getY();
if(startY-y<-60){
Log.w(TAG, "scroll down");
mHeader.setVisibility(View.VISIBLE);
}else if(startY-y>60){
Log.w(TAG, "scroll up");
mHeader.setVisibility(View.GONE);
}
}
return false;
}
});