我有以下代码来监听Swipe操作以在ViewFlipper中的GridViews之间导航。但是，它会不一致地检测到滑动。我将Gesture Listener添加到每个GridView以及GridView中的每个项目上。还有什么我想念的吗？
完整代码如下：
public class ListNewsActivity extends Activity implements OnGestureListener {
String TAG = "ListNewsActivity";
private static final int SWIPE_MIN_DISTANCE = 120;
private static final int SWIPE_MAX_OFF_PATH = 250;
private static final int SWIPE_THRESHOLD_VELOCITY = 200;
private static final int DIALOG_PLEASE_WAIT = 100;
private GestureDetector gestureDetector;
View.OnTouchListener gestureListener;
private Animation slideLeftIn;
private Animation slideLeftOut;
private Animation slideRightIn;
private Animation slideRightOut;
private static int MAX_STREAMS = AppSettings.getStreamList().size();
Context context;
ViewFlipper flipper;
StreamHeader header;
int currentStreamIndex = 0;
ArrayList<StreamNav> navList = new ArrayList<StreamNav>();
ArrayList<StreamGridView> gridList = new ArrayList<StreamGridView>();
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
context = getApplicationContext();
super.onCreate(savedInstanceState);
setContentView(R.layout.stream);
if (AppSettings.userToken == null) {
AppSettings.getUserToken(context);
}
header = (StreamHeader) findViewById(R.id.stream_header);
setHeaderTitle();
flipper = (ViewFlipper)findViewById(R.id.stream_flipper);
boolean loadData = false;
Log.v(TAG, "No. of streams: " + String.valueOf(AppSettings.getStreamList().size()));
for (Stream stream : AppSettings.getStreamList()) {
Log.v(TAG, "Checking Stream " + stream.getName());
if (stream.getPosts() == null || stream.getPosts().size() == 0) {
loadData = true;
Log.v(TAG, "Empty Stream for " + stream.getBlogId() + ". Data will be loaded.");
break;
}
else {
Log.v(TAG, "Stream " + stream.getName() + " is populated. Posts: " + String.valueOf(stream.getPosts().size()));
}
}
setupNavAndGrids();
if (loadData) {
new LoadStreamTask().execute();
}
else {
populateGrids();
}
slideLeftIn = AnimationUtils.loadAnimation(this, R.anim.stream_flipper_slidein_from_right);
slideLeftOut = AnimationUtils.loadAnimation(this, R.anim.stream_flipper_slideout_to_left);
slideRightIn = AnimationUtils.loadAnimation(this, R.anim.stream_flipper_slidein_from_left);
slideRightOut = AnimationUtils.loadAnimation(this, R.anim.stream_flipper_slideout_to_right);
gestureDetector = new GestureDetector(new MyGestureDetector());
gestureListener = new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
if (gestureDetector.onTouchEvent(event)) {
return true;
}
return false;
}
};
}
public void setupNavAndGrids() {
LinearLayout llNav = (LinearLayout) findViewById(R.id.stream_nav_layout);
View.OnClickListener navOnClickListener = new View.OnClickListener() {
@Override
public void onClick(View v) {
StreamNav nav = (StreamNav)v;
navigateToStream(nav.getStreamIndex());
}
};
for (int i = 0; i < MAX_STREAMS; i++) {
StreamNav nav = new StreamNav(context, null);
nav.setStreamIndex(i);
nav.setOnClickListener(navOnClickListener);
navList.add(nav);
llNav.addView(nav);
StreamGridView gv = new StreamGridView(context, null);
gv.setOnTouchListener(gestureListener);
gridList.add(gv);
flipper.addView(gv);
}
navList.get(0).setSelected(true);
}
void navigateToStream(int newStreamIndex) {
for (StreamNav nav : navList) {
if (nav.getStreamIndex() == newStreamIndex) {
nav.setSelected(true);
}
else {
nav.setSelected(false);
}
}
Log.v(TAG, "Navigate To Stream: currentStreamIndex=" + String.valueOf(currentStreamIndex) + " newStreamIndex " + String.valueOf(newStreamIndex));
if (currentStreamIndex < newStreamIndex) {
int ctr = newStreamIndex - currentStreamIndex;
for (int i = 0; i < ctr; i++) {
showNext();
}
}
else {
int ctr = currentStreamIndex - newStreamIndex;
for (int i = 0; i < ctr; i++) {
showPrevious();
}
}
}
public void showNext() {
Toast.makeText(context, "Show Next Page for Flipper", Toast.LENGTH_LONG);
flipper.setInAnimation(this, R.anim.stream_flipper_slidein_from_right);
flipper.setOutAnimation(this, R.anim.stream_flipper_slideout_to_left);
flipper.showNext();
setStreamIndex(1);
setHeaderTitle();
}
public void showPrevious() {
Toast.makeText(context, "Show Previous Page for Flipper", Toast.LENGTH_LONG);
flipper.setInAnimation(this, R.anim.stream_flipper_slidein_from_left);
flipper.setOutAnimation(this, R.anim.stream_flipper_slideout_to_right);
flipper.showPrevious();
setStreamIndex(-1);
setHeaderTitle();
}
void setStreamIndex(int step) {
if (step == 1) {
if (currentStreamIndex == MAX_STREAMS) {
currentStreamIndex = 0;
}
else {
currentStreamIndex++;
}
}
else {
// -1 which means previous
if (currentStreamIndex == 0) {
currentStreamIndex = MAX_STREAMS - 1;
}
else {
currentStreamIndex--;
}
}
}
void setHeaderTitle() {
header.setTitle(AppSettings.getStreamList().get(currentStreamIndex).getName());
}
void populateGrids() {
int pos = -1;
for (StreamGridView sgv : gridList) {
pos++;
Log.v(TAG, "Loading Stream for " + AppSettings.getStreamList().get(pos).getName() + "; Posts: " + String.valueOf(AppSettings.getStreamList().get(pos).getPosts().size()));
ArrayList<Post> posts = AppSettings.getStreamList().get(pos).getPosts();
sgv.adapter = new LazyPostItemAdapter(ListNewsActivity.this, posts, gestureListener);
sgv.gvStream.setAdapter(sgv.adapter);
}
}
class LoadStreamTask extends AsyncTask<Void, String, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
showDialog(DIALOG_PLEASE_WAIT);
}
@Override
protected Void doInBackground(Void... unused) {
for (Stream stream : AppSettings.getStreamList()) {
if (stream.getBlogId().equalsIgnoreCase("popular")) {
stream.setPosts(Post.getPopularStream());
}
else if (stream.getBlogId().equalsIgnoreCase("recent")) {
stream.setPosts(Post.getRecentStream());
}
else {
Blog blog = Blog.getBlog(stream.getBlogId());
stream.setPosts(Post.getPostsForBlog(blog));
}
}
return null;
}
@Override
protected void onPostExecute(Void unused) {
populateGrids();
dismissDialog(DIALOG_PLEASE_WAIT);
}
}
@Override
protected Dialog onCreateDialog(int id) {
switch (id) {
case DIALOG_PLEASE_WAIT:
ProgressDialog mProgressDialog;
mProgressDialog = new ProgressDialog(this);
mProgressDialog.setMessage("Loading Streams...");
mProgressDialog.setCancelable(false);
mProgressDialog.show();
return mProgressDialog;
default:
return null;
}
}
class MyGestureDetector extends SimpleOnGestureListener {
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
Log.v(TAG, "onFling");
try {
if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
return false;
// right to left swipe
if(e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
flipper.setInAnimation(slideLeftIn);
flipper.setOutAnimation(slideLeftOut);
flipper.showNext();
} else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
flipper.setInAnimation(slideRightIn);
flipper.setOutAnimation(slideRightOut);
flipper.showPrevious();
}
} catch (Exception e) {
// nothing
}
return false;
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if (gestureDetector.onTouchEvent(event))
return true;
else
return false;
}
@Override
public boolean onDown(MotionEvent e) {
// TODO Auto-generated method stub
return false;
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
// TODO Auto-generated method stub
return false;
}
@Override
public void onLongPress(MotionEvent e) {
// TODO Auto-generated method stub
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
float distanceY) {
// TODO Auto-generated method stub
return false;
}
@Override
public void onShowPress(MotionEvent e) {
// TODO Auto-generated method stub
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
// TODO Auto-generated method stub
return false;
}
}
答案 0 :(得分：3)
我一直在StackOverflow上看到相同的滑动手势检测代码，所以我试图将其清理一下。这是一个通用的侦听器，它可以为右或左滑动触发事件（很容易扩展到其他
public class SwipeListener extends GestureDetector.SimpleOnGestureListener {
private static final int SWIPE_MIN_DISTANCE = 120;
private static final int SWIPE_MAX_OFF_PATH = 250;
private static final int SWIPE_THRESHOLD_VELOCITY = 200;
private SwipeHandler handler;
public SwipeHandler getHandler() {
return handler;
}
public void setHandler(SwipeHandler handler) {
this.handler = handler;
}
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
return false;
// left
if (e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE
&& Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
if (handler != null) {
handler.onLeft();
return true;
}
// right
} else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE
&& Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
if (handler != null) {
handler.onRight();
return true;
}
}
return super.onFling(e1, e2, velocityX, velocityY);
}
public static abstract class SwipeHandler{
public void onLeft() {}
public void onRight() {}
}
}
然后在任何地方使用它，只需创建一个实例，设置滑动事件处理程序并附加它：
SwipeListener swipeListener = new SwipeListener();
swipeListener.setHandler(new SwipeListener.SwipeHandler() {
@Override
public void onRight() {
doSomething();
}
});
someView.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
return gestureDetector.onTouchEvent(event);
}
});
答案 1 :(得分：1)
我在这里有几个问题/意见：
问：你能不一致地阐述你的意思吗？没有检测到滑动时是否有任何模式？它有用吗？如果是的话，何时？问：在您的主Activity中，在over-riden onTouchEvent（MotionEvent me）方法中，您是否会像这样返回myGestureDetector.onTouchEvent（me）？
@Override
public boolean onTouchEvent(MotionEvent me) {
return myGestureDetector.onTouchEvent(me);
}
这里myGestureDetector是MyGestureDetector类的一个对象，它基本上将你的GestureDetector附加到触摸事件
观察：你可以在手势处理完成后立即返回true，告诉android手势捕获完成，例如
if(e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
flipper.setInAnimation(slideLeftIn);
flipper.setOutAnimation(slideLeftOut);
flipper.showNext();
//return true if the gesture event is consumed
return true;
} else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
flipper.setInAnimation(slideRightIn);
flipper.setOutAnimation(slideRightOut);
flipper.showPrevious();
//return true if the gesture event is consumed
return true;
}
答案 2 :(得分：0)
1）你在viewflipper中添加了所有的网格视图。
viewFlipper = (ViewFlipper)findViewById(R.id.flipper);
slideLeftIn = AnimationUtils.loadAnimation(this, R.anim.slide_left_in);
slideLeftOut = AnimationUtils.loadAnimation(this, R.anim.slide_left_out);
slideRightIn = AnimationUtils.loadAnimation(this, R.anim.slide_right_in);
slideRightOut = AnimationUtils.loadAnimation(this, R.anim.slide_right_out);
gestureDetector = new GestureDetector(new MyGestureDetector());
gestureListener = new View.OnTouchListener()
{
public boolean onTouch(View v, MotionEvent event)
{
if (gestureDetector.onTouchEvent(event))
{
return true;
}
else{
return false;}
}
};
我已在我的代码中添加了这些工作正常。请检查这个让我知道