我有一个自定义列表视图，它有一个自定义的inexscroller，当你滚动列表时它会自动绘制。现在，当我的listview没有太多项目时，这看起来并不好看。所以我想要做的是当项目小于可滚动的特定数字时隐藏IndexScroller。我做了一切，但我无法隐藏列表视图。请帮忙：
以下是使用的类：
IndexableListViewActivity
public class IndexableListViewActivity extends Activity implements OnClickListener
{
private ArrayList<String> mItems;
private IndexableListView mListView;
TextView MyTasks, TeamTasks, username, fullusername;
RelativeLayout listlay;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mItems = new ArrayList<String>();
mItems.add("Diary of a Wimpy Kid 6: Cabin Fever");
mItems.add("Steve Jobs");
mItems.add("Inheritance (The Inheritance Cycle)");
mItems.add("11/22/63: A Novel");
mItems.add("The Hunger Games");
mItems.add("The LEGO Ideas Book");
mItems.add("Explosive Eighteen: A Stephanie Plum Novel");
mItems.add("Catching Fire (The Second Book of the Hunger Games)");
mItems.add("Elder Scrolls V: Skyrim: Prima Official Game Guide");
mItems.add("Death Comes to Pemberley");
mItems.add("Diary of a Wimpy Kid 6: Cabin Fever");
mItems.add("Steve Jobs");
mItems.add("Inheritance (The Inheritance Cycle)");
mItems.add("11/22/63: A Novel");
mItems.add("The Hunger Games");
mItems.add("The LEGO Ideas Book");
mItems.add("Explosive Eighteen: A Stephanie Plum Novel");
mItems.add("Catching Fire (The Second Book of the Hunger Games)");
mItems.add("Elder Scrolls V: Skyrim: Prima Official Game Guide");
mItems.add("Death Comes to Pemberley");
mItems.add("Make this list longer");
mItems.add("A");
mItems.add("B");
// mItems.add("C");
// mItems.add("D");
// mItems.add("E");
// mItems.add("F");
// mItems.add("H");
// mItems.add("I");
// mItems.add("J");
// mItems.add("K");
// mItems.add("L");
// mItems.add("M");
// mItems.add("N");
// mItems.add("O");
// mItems.add("P");
// mItems.add("Q");
// mItems.add("R");
// mItems.add("S");
// mItems.add("T");
// mItems.add("U");
// mItems.add("V");
// mItems.add("W");
// mItems.add("X");
// mItems.add("Y");
// mItems.add("Z");
Collections.sort(mItems);
ContentAdapter adapter = new ContentAdapter(this,
android.R.layout.simple_list_item_1, mItems);
mListView = (IndexableListView) findViewById(R.id.listview);
mListView.setAdapter(adapter);
mListView.setFastScrollEnabled(true);
MyTasks = (TextView)findViewById(R.id.myTasks);
MyTasks.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
MyTasks.setBackgroundResource(R.drawable.rectangle_selected);
TeamTasks.setBackgroundResource(R.drawable.rectangle);
if(mListView.getLastVisiblePosition() + 1 == mListView.getCount()) {
Toast.makeText(getBaseContext(), "No need to scroll", Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(getBaseContext(), "Need to scroll", Toast.LENGTH_SHORT).show();
}
}
});
TeamTasks = (TextView)findViewById(R.id.teamTasks);
TeamTasks.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
TeamTasks.setBackgroundResource(R.drawable.rectangle_selected);
MyTasks.setBackgroundResource(R.drawable.rectangle);
}
});
}
private class ContentAdapter extends ArrayAdapter<String> implements SectionIndexer {
private String mSections = "#ABCDEFGHIJKLMNOPQRSTUVWXYZ";
public ContentAdapter(Context context, int textViewResourceId,
List<String> objects) {
super(context, textViewResourceId, objects);
}
@Override
public int getPositionForSection(int section) {
// If there is no item for current section, previous section will be selected
for (int i = section; i >= 0; i--) {
for (int j = 0; j < getCount(); j++) {
if (i == 0) {
// For numeric section
for (int k = 0; k <= 9; k++) {
if (StringMatcher.match(String.valueOf(getItem(j).charAt(0)), String.valueOf(k)))
return j;
}
} else {
if (StringMatcher.match(String.valueOf(getItem(j).charAt(0)), String.valueOf(mSections.charAt(i))))
return j;
}
}
}
return 0;
}
@Override
public int getSectionForPosition(int position) {
return 0;
}
@Override
public Object[] getSections() {
String[] sections = new String[mSections.length()];
for (int i = 0; i < mSections.length(); i++)
sections[i] = String.valueOf(mSections.charAt(i));
return sections;
}
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
}
StrngMatcher.java
public class StringMatcher {
public static boolean match(String value, String keyword) {
if (value == null || keyword == null)
return false;
if (keyword.length() > value.length())
return false;
int i = 0, j = 0;
do {
int vi = value.charAt(i);
int kj = keyword.charAt(j);
if (isKorean(vi) && isInitialSound(kj)) {
} else {
if (vi == kj) {
i++;
j++;
} else if (j > 0)
break;
else
i++;
}
} while (i < value.length() && j < keyword.length());
return (j == keyword.length())? true : false;
}
private static boolean isKorean(int i) {
return false;
}
private static boolean isInitialSound(int i) {
return false;
}
}
IndexableListView.java
public class IndexableListView extends ListView {
private boolean mIsFastScrollEnabled = false;
private IndexScroller mScroller = null;
private GestureDetector mGestureDetector = null;
public IndexableListView(Context context) {
super(context);
}
public IndexableListView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public IndexableListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public boolean isFastScrollEnabled() {
return mIsFastScrollEnabled;
}
@Override
public void setFastScrollEnabled(boolean enabled) {
mIsFastScrollEnabled = enabled;
if (mIsFastScrollEnabled) {
if (mScroller == null)
mScroller = new IndexScroller(getContext(), this);
}
else {
if (mScroller != null) {
mScroller.hide();
mScroller = null;
}
}
}
@Override
public void draw(Canvas canvas) {
super.draw(canvas);
// Overlay index bar
if (mScroller != null)
mScroller.draw(canvas);
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
// Intercept ListView's touch event
if (mScroller != null && mScroller.onTouchEvent(ev))
return true;
if (mGestureDetector == null) {
mGestureDetector = new GestureDetector(getContext(), new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2,
float velocityX, float velocityY) {
// If fling happens, index bar shows
if(mScroller!=null)
mScroller.show();
return super.onFling(e1, e2, velocityX, velocityY);
}
});
}
mGestureDetector.onTouchEvent(ev);
return super.onTouchEvent(ev);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
return true;
}
@Override
public void setAdapter(ListAdapter adapter) {
super.setAdapter(adapter);
if (mScroller != null)
mScroller.setAdapter(adapter);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
if (mScroller != null)
mScroller.onSizeChanged(w, h, oldw, oldh);
}
}
IndexScroller.java
public class IndexScroller {
private float mIndexbarWidth;
private float mIndexbarMargin;
private float mPreviewPadding;
private float mDensity;
private float mScaledDensity;
private float mAlphaRate;
private int mState = STATE_HIDDEN;
private int mListViewWidth;
private int mListViewHeight;
private int mCurrentSection = -1;
private boolean mIsIndexing = false;
private ListView mListView = null;
private SectionIndexer mIndexer = null;
private String[] mSections = null;
private RectF mIndexbarRect;
private static final int STATE_HIDDEN = 0;
private static final int STATE_SHOWING = 1;
private static final int STATE_SHOWN = 2;
private static final int STATE_HIDING = 3;
public IndexScroller(Context context, ListView lv) {
mDensity = context.getResources().getDisplayMetrics().density;
mScaledDensity = context.getResources().getDisplayMetrics().scaledDensity;
mListView = lv;
setAdapter(mListView.getAdapter());
mIndexbarWidth = 20 * mDensity;
mIndexbarMargin = 2 * mDensity;
mPreviewPadding = 5 * mDensity;
}
public void draw(Canvas canvas) {
if (mState == STATE_HIDDEN)
return;
// mAlphaRate determines the rate of opacity
Paint indexbarPaint = new Paint();
indexbarPaint.setColor(Color.BLACK);
indexbarPaint.setAlpha((int) (64 * mAlphaRate));
indexbarPaint.setAntiAlias(true);
canvas.drawRoundRect(mIndexbarRect, 5 * mDensity, 5 * mDensity, indexbarPaint);
if (mSections != null && mSections.length > 0) {
// Preview is shown when mCurrentSection is set
if (mCurrentSection >= 0) {
Paint previewPaint = new Paint();
previewPaint.setColor(Color.BLACK);
previewPaint.setAlpha(96);
previewPaint.setAntiAlias(true);
previewPaint.setShadowLayer(3, 0, 0, Color.argb(64, 0, 0, 0));
Paint previewTextPaint = new Paint();
previewTextPaint.setColor(Color.WHITE);
previewTextPaint.setAntiAlias(true);
previewTextPaint.setTextSize(50 * mScaledDensity);
float previewTextWidth = previewTextPaint.measureText(mSections[mCurrentSection]);
float previewSize = 2 * mPreviewPadding + previewTextPaint.descent() - previewTextPaint.ascent();
RectF previewRect = new RectF((mListViewWidth - previewSize) / 2
, (mListViewHeight - previewSize) / 2
, (mListViewWidth - previewSize) / 2 + previewSize
, (mListViewHeight - previewSize) / 2 + previewSize);
canvas.drawRoundRect(previewRect, 5 * mDensity, 5 * mDensity, previewPaint);
canvas.drawText(mSections[mCurrentSection], previewRect.left + (previewSize - previewTextWidth) / 2 - 1
, previewRect.top + mPreviewPadding - previewTextPaint.ascent() + 1, previewTextPaint);
}
Paint indexPaint = new Paint();
indexPaint.setColor(Color.WHITE);
indexPaint.setAlpha((int) (255 * mAlphaRate));
indexPaint.setAntiAlias(true);
indexPaint.setTextSize(12 * mScaledDensity);
float sectionHeight = (mIndexbarRect.height() - 2 * mIndexbarMargin) / mSections.length;
float paddingTop = (sectionHeight - (indexPaint.descent() - indexPaint.ascent())) / 2;
for (int i = 0; i < mSections.length; i++) {
float paddingLeft = (mIndexbarWidth - indexPaint.measureText(mSections[i])) / 2;
canvas.drawText(mSections[i], mIndexbarRect.left + paddingLeft
, mIndexbarRect.top + mIndexbarMargin + sectionHeight * i + paddingTop - indexPaint.ascent(), indexPaint);
}
}
}
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
// If down event occurs inside index bar region, start indexing
if (mState != STATE_HIDDEN && contains(ev.getX(), ev.getY())) {
setState(STATE_SHOWN);
// It demonstrates that the motion event started from index bar
mIsIndexing = true;
// Determine which section the point is in, and move the list to that section
mCurrentSection = getSectionByPoint(ev.getY());
mListView.setSelection(mIndexer.getPositionForSection(mCurrentSection));
return true;
}
break;
case MotionEvent.ACTION_MOVE:
if (mIsIndexing) {
// If this event moves inside index bar
if (contains(ev.getX(), ev.getY())) {
// Determine which section the point is in, and move the list to that section
mCurrentSection = getSectionByPoint(ev.getY());
mListView.setSelection(mIndexer.getPositionForSection(mCurrentSection));
}
return true;
}
break;
case MotionEvent.ACTION_UP:
if (mIsIndexing) {
mIsIndexing = false;
mCurrentSection = -1;
}
if (mState == STATE_SHOWN)
setState(STATE_HIDING);
break;
}
return false;
}
public void onSizeChanged(int w, int h, int oldw, int oldh) {
mListViewWidth = w;
mListViewHeight = h;
mIndexbarRect = new RectF(w - mIndexbarMargin - mIndexbarWidth
, mIndexbarMargin
, w - mIndexbarMargin
, h - mIndexbarMargin);
}
public void show() {
if (mState == STATE_HIDDEN)
setState(STATE_SHOWING);
else if (mState == STATE_HIDING)
setState(STATE_HIDING);
}
public void hide() {
if (mState == STATE_SHOWN)
setState(STATE_HIDING);
}
public void setAdapter(Adapter adapter) {
if (adapter instanceof SectionIndexer) {
mIndexer = (SectionIndexer) adapter;
mSections = (String[]) mIndexer.getSections();
}
}
private void setState(int state) {
if (state < STATE_HIDDEN || state > STATE_HIDING)
return;
mState = state;
switch (mState) {
case STATE_HIDDEN:
// Cancel any fade effect
mHandler.removeMessages(0);
break;
case STATE_SHOWING:
// Start to fade in
mAlphaRate = 0;
fade(0);
break;
case STATE_SHOWN:
// Cancel any fade effect
mHandler.removeMessages(0);
break;
case STATE_HIDING:
// Start to fade out after three seconds
mAlphaRate = 1;
fade(3000);
break;
}
}
private boolean contains(float x, float y) {
// Determine if the point is in index bar region, which includes the right margin of the bar
return (x >= mIndexbarRect.left && y >= mIndexbarRect.top && y <= mIndexbarRect.top + mIndexbarRect.height());
}
private int getSectionByPoint(float y) {
if (mSections == null || mSections.length == 0)
return 0;
if (y < mIndexbarRect.top + mIndexbarMargin)
return 0;
if (y >= mIndexbarRect.top + mIndexbarRect.height() - mIndexbarMargin)
return mSections.length - 1;
return (int) ((y - mIndexbarRect.top - mIndexbarMargin) / ((mIndexbarRect.height() - 2 * mIndexbarMargin) / mSections.length));
}
private void fade(long delay) {
mHandler.removeMessages(0);
mHandler.sendEmptyMessageAtTime(0, SystemClock.uptimeMillis() + delay);
}
private Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (mState) {
case STATE_SHOWING:
// Fade in effect
mAlphaRate += (1 - mAlphaRate) * 0.2;
if (mAlphaRate > 0.9) {
mAlphaRate = 1;
setState(STATE_SHOWN);
}
mListView.invalidate();
fade(10);
break;
case STATE_SHOWN:
// If no action, hide automatically
setState(STATE_HIDING);
break;
case STATE_HIDING:
// Fade out effect
mAlphaRate -= mAlphaRate * 0.2;
if (mAlphaRate < 0.1) {
mAlphaRate = 0;
setState(STATE_HIDDEN);
}
mListView.invalidate();
fade(10);
break;
}
}
};
}
在此， IndexableListView 和 IndexScroller 位于同一个包中，其他2个类位于2个不同的包中。
请帮助如何隐藏IndexScroller，以便它不会出现在触摸上。
答案 0 :(得分：0)
由于没有人愿意回答，这就是要做的事情。
对于所有设置状态的行，如IndexScroller.java所示，将它们包含在：
isTrue = mListView.getLastVisiblePosition() + 1 == mListView.getCount();
if(!isTrue)
{
//State Shown
}