Android ListView OnItemClick 事件有时会触发,但并非总是如此
我的 Android ListView 组件有一个非常奇怪的问题。
情况:我基本上利用 setOnItemClickListener 方法,然后重写“onItemClick”方法,以在单击列表视图中的项目时实现自定义操作。
问题: onItemClick 事件按其应该在项目点击时触发的方式触发,但是在点击了相当数量的项目 (20-30-40) 后,突然只有一个项目变得不可点击,这意味着当您点击时什么也不会发生点击它。与此同时,所有其他项目仍然可以点击。
我已经重写了 ListView 组件来捕获“dispatchTouchEvent”(参见下面的代码),这表明当一个项目突然变得不可点击时,dispatchTouchEvent 确实仍然被触发,具有合理的 X 和 Y 坐标,但不知何故“onItemClick” “事件未能触发。
public class ExtendedListView extends ListView
{
public ExtendedListView(Context context) {
super(context);
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev)
{
Log.v("dispatchTouchEvent", "click|X:" + ev.getX() + "|Y:" + ev.getY());
return super.dispatchTouchEvent(ev);
}
任何
启动ListView 的方法:
@SuppressWarnings("unchecked")
private void renderHomeScreenItemsList() {
HomeScreenItemAdapter m_adapter;
ArrayList<HomeScreenItem> lHomeScreenItems = null;
LayoutParams lpHomeScreenItems = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
lpHomeScreenItems.leftMargin = Util.dipsToPx(0, this);
lpHomeScreenItems.topMargin = Util.dipsToPx(155, this);
lpHomeScreenItems.gravity = 3; //3 = LEFT. Some gravity is necessary.
lvHomeScreenItems = new ExtendedListView(this);
lvHomeScreenItems.setLayoutParams(lpHomeScreenItems);
ColorDrawable sage = new ColorDrawable(this.getResources().getColor(R.color.HomeScreenDividerColor));
lvHomeScreenItems.setDivider(sage);
lvHomeScreenItems.setDividerHeight(1);
lvHomeScreenItems.setCacheColorHint(Color.WHITE);
lvHomeScreenItems.setBackgroundColor(Color.WHITE);
lHomeScreenItems = new ArrayList<HomeScreenItem>();
Iterator<EnabledSection> ite = Global.EnabledSectionsVector.iterator();
while (ite.hasNext()) {
EnabledSection es = (EnabledSection) ite.next();
HomeScreenItem h1 = new HomeScreenItem();
h1.setItemText(es.FunctionTitle);
h1.setFunctionName(es.FunctionName);
int imageId = getResources().getIdentifier("homescreen_" + es.FunctionName.toLowerCase(), "drawable", "XXXXXXXXX");
h1.setItemImageResourceId(imageId);
lHomeScreenItems.add(h1);
}
HomeScreenItem hCopyright = new HomeScreenItem();
hCopyright.setItemText("copyright");
hCopyright.setItemImageResourceId(-1);
lHomeScreenItems.add(hCopyright);
m_adapter = new HomeScreenItemAdapter(this, R.layout.row, lHomeScreenItems);
lvHomeScreenItems.setAdapter(m_adapter);
lvHomeScreenItems.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Log.v("onItemClick", "Click Detected");
HomeScreenItem hmi = (HomeScreenItem)parent.getItemAtPosition(position);
Boolean blnAcceptClick = true;
if (WrapperWebView == null)
blnAcceptClick = true;
else
if (WrapperWebView.getProgress() != 100)
blnAcceptClick = false;
if (hmi.getItemImageResourceId() != -1 && blnAcceptClick)
{
Global.IsLoadingWrapper = true;
vSelectedItem = view;
ImageView ivIcon = (ImageView)view.findViewById(R.id.rightarrow);
LinearLayout ll = (LinearLayout)view.findViewById(R.id.RowContainer);
TextView ll2 = (TextView)view.findViewById(R.id.toptext);
ll.setBackgroundResource(R.color.BlueActive);
ll2.setBackgroundResource(R.color.BlueActive);
ll2.setTextColor(Color.WHITE);
int[] intCoordinates = new int[2];
view.getLocationInWindow(intCoordinates);
lpLoadingSpinner.topMargin = intCoordinates[1] - Util.dipsToPx(10, HomeScreen.this);
ivLoadingSpinner.setVisibility(View.VISIBLE);
ivLoadingSpinner.bringToFront();
LoadingSpinnerAnimation.start();
ivIcon.setVisibility(View.GONE);
ivClickedItemIcon = ivIcon;
InitializeWebView(hmi.getFunctionName());
}
}
});
}
帮助将不胜感激。该错误已确认发生在多个设备和多个 Android 版本上。
更新:问题已解决 我已经设法找到问题并解决它。基本上,项目列表包含所有“正常”项目(在我的上下文中),除了底部的项目,它是一个“版权”项目,带有必须可单击的链接(蓝色)。为了使此点击效果发挥作用,我使用了:
tt.setMovementMethod(LinkMovementMethod.getInstance());
如果正在渲染的项目是版权项目。
但是,如果正在渲染的项目是“正常”项目,我不会反驳这种效果,因此仅在渲染正常项目时添加下面的行,问题就消失了:
tt.setMovementMethod(null);
完整的示例代码(删除了不相关的代码) )
public class HomeScreenItemAdapter extends ArrayAdapter<HomeScreenItem> {
private ArrayList<HomeScreenItem> items;
public HomeScreenItemAdapter(Context context, int textViewResourceId, ArrayList<HomeScreenItem> items) {
super(context, textViewResourceId, items);
this.items = items;
}
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
View v = convertView;
if (v == null) {
LayoutInflater vi = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.row, null);
}
HomeScreenItem o = items.get(position);
if (o != null) {
TextView tt = (TextView) v.findViewById(R.id.toptext);
if (iv != null && tt != null)
{
if (position != (items.size() - 1))
{
tt.setMovementMethod(null);
}
else
{
//last element, so setup element to show copyright notice instead
tt.setMovementMethod(LinkMovementMethod.getInstance()); //this makes the link clickable
}
}
}
return v;
}
}
I have a very wierd problem with the Android ListView component.
Situation: I'm basically utilizing the setOnItemClickListener method and subsequently overriding the "onItemClick" method to implement a custom action when clicking on an item in the listview.
Problem: The onItemClick event fires as it should on an item tap, however having tapped a decent amount of items (20-30-40), suddenly one, and only one, of the items become un-tapable, meaning nothing happens when you tap it. Meanwhile, all the other items are still tapable.
I have overridden the ListView component to capture the "dispatchTouchEvent" (see code below), and that reveals that when an item suddenly becomes un-tapable, the dispatchTouchEvent is indeed still fired, with reasonable X and Y coordinates, but somehow the "onItemClick" event failes to fire.
public class ExtendedListView extends ListView
{
public ExtendedListView(Context context) {
super(context);
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev)
{
Log.v("dispatchTouchEvent", "click|X:" + ev.getX() + "|Y:" + ev.getY());
return super.dispatchTouchEvent(ev);
}
}
Method that initiates the ListView:
@SuppressWarnings("unchecked")
private void renderHomeScreenItemsList() {
HomeScreenItemAdapter m_adapter;
ArrayList<HomeScreenItem> lHomeScreenItems = null;
LayoutParams lpHomeScreenItems = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
lpHomeScreenItems.leftMargin = Util.dipsToPx(0, this);
lpHomeScreenItems.topMargin = Util.dipsToPx(155, this);
lpHomeScreenItems.gravity = 3; //3 = LEFT. Some gravity is necessary.
lvHomeScreenItems = new ExtendedListView(this);
lvHomeScreenItems.setLayoutParams(lpHomeScreenItems);
ColorDrawable sage = new ColorDrawable(this.getResources().getColor(R.color.HomeScreenDividerColor));
lvHomeScreenItems.setDivider(sage);
lvHomeScreenItems.setDividerHeight(1);
lvHomeScreenItems.setCacheColorHint(Color.WHITE);
lvHomeScreenItems.setBackgroundColor(Color.WHITE);
lHomeScreenItems = new ArrayList<HomeScreenItem>();
Iterator<EnabledSection> ite = Global.EnabledSectionsVector.iterator();
while (ite.hasNext()) {
EnabledSection es = (EnabledSection) ite.next();
HomeScreenItem h1 = new HomeScreenItem();
h1.setItemText(es.FunctionTitle);
h1.setFunctionName(es.FunctionName);
int imageId = getResources().getIdentifier("homescreen_" + es.FunctionName.toLowerCase(), "drawable", "XXXXXXXXX");
h1.setItemImageResourceId(imageId);
lHomeScreenItems.add(h1);
}
HomeScreenItem hCopyright = new HomeScreenItem();
hCopyright.setItemText("copyright");
hCopyright.setItemImageResourceId(-1);
lHomeScreenItems.add(hCopyright);
m_adapter = new HomeScreenItemAdapter(this, R.layout.row, lHomeScreenItems);
lvHomeScreenItems.setAdapter(m_adapter);
lvHomeScreenItems.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Log.v("onItemClick", "Click Detected");
HomeScreenItem hmi = (HomeScreenItem)parent.getItemAtPosition(position);
Boolean blnAcceptClick = true;
if (WrapperWebView == null)
blnAcceptClick = true;
else
if (WrapperWebView.getProgress() != 100)
blnAcceptClick = false;
if (hmi.getItemImageResourceId() != -1 && blnAcceptClick)
{
Global.IsLoadingWrapper = true;
vSelectedItem = view;
ImageView ivIcon = (ImageView)view.findViewById(R.id.rightarrow);
LinearLayout ll = (LinearLayout)view.findViewById(R.id.RowContainer);
TextView ll2 = (TextView)view.findViewById(R.id.toptext);
ll.setBackgroundResource(R.color.BlueActive);
ll2.setBackgroundResource(R.color.BlueActive);
ll2.setTextColor(Color.WHITE);
int[] intCoordinates = new int[2];
view.getLocationInWindow(intCoordinates);
lpLoadingSpinner.topMargin = intCoordinates[1] - Util.dipsToPx(10, HomeScreen.this);
ivLoadingSpinner.setVisibility(View.VISIBLE);
ivLoadingSpinner.bringToFront();
LoadingSpinnerAnimation.start();
ivIcon.setVisibility(View.GONE);
ivClickedItemIcon = ivIcon;
InitializeWebView(hmi.getFunctionName());
}
}
});
}
Any help would be greatly appeciated. The bug is confirmed to happen on multiple devices and on multiple android versions.
UPDATE: Problem fixed
I've managed to find the problem and fix it. Basically, the list of items contained all "normal" items (in my context), except for the bottom one, which was a "copyright" item with a link (in blue) that had to be clickable. To get this click effect working, I used:
tt.setMovementMethod(LinkMovementMethod.getInstance());
if the item being rendered was the copyright item.
However, I didn't counter that effect if the item being rendered was a "normal" item, so by only adding the line below when a normal item is rendered, the problem went away:
tt.setMovementMethod(null);
Full example code (with non-relevant code removed)
public class HomeScreenItemAdapter extends ArrayAdapter<HomeScreenItem> {
private ArrayList<HomeScreenItem> items;
public HomeScreenItemAdapter(Context context, int textViewResourceId, ArrayList<HomeScreenItem> items) {
super(context, textViewResourceId, items);
this.items = items;
}
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
View v = convertView;
if (v == null) {
LayoutInflater vi = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.row, null);
}
HomeScreenItem o = items.get(position);
if (o != null) {
TextView tt = (TextView) v.findViewById(R.id.toptext);
if (iv != null && tt != null)
{
if (position != (items.size() - 1))
{
tt.setMovementMethod(null);
}
else
{
//last element, so setup element to show copyright notice instead
tt.setMovementMethod(LinkMovementMethod.getInstance()); //this makes the link clickable
}
}
}
return v;
}
}
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