我使用https://github.com/woozzu/IndexableListView/tree/master/src/com/woozzu/android/widget为自己制作了一个
并将 ListView 更改为 RecylerView
public class IndexableRecylerView extends RecyclerView implements RecyclerView.OnItemTouchListener{
public IndexScroller mScroller = null;
public IndexableRecylerView(Context context) {
super(context);
init();
}
public IndexableRecylerView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public IndexableRecylerView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
public void init() {
addOnItemTouchListener(this);
}
public void setFastScrollEnabled(boolean enable) {
if (enable) {
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) {
if (mScroller != null)
mScroller.show();
// Intercept ListView's touch event
if (mScroller != null && mScroller.onTouchEvent(ev))
return true;
return super.onTouchEvent(ev);
}
public void setIndexAdapter(List<String> sectionName, List<Integer> sectionPosition) {
if (mScroller != null)
mScroller.notifyChanges(sectionName, sectionPosition);
}
@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);
}
@Override
public void stopScroll()
{
try
{
super.stopScroll();
}
catch( NullPointerException exception )
{
Log.i("RecyclerView", "NPE caught in stopScroll");
}
}
@Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
if (mScroller != null && mScroller.contains(e.getX(), e.getY())) {
mScroller.show();
return true;
}else{
return false;
}
}
@Override
public void onTouchEvent(RecyclerView rv, MotionEvent e) {
}
}
此类在侧面绘制索引器，并允许您在它们上滚动并滚动 recylerview ..
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 RecyclerView recyclerView = null;
public List<String> mSections = new ArrayList<>();
public List<Integer> mSectionPosition = new ArrayList<>();
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, RecyclerView lv) {
mDensity = context.getResources().getDisplayMetrics().density;
mScaledDensity = context.getResources().getDisplayMetrics().scaledDensity;
recyclerView = lv;
mIndexbarWidth = 20 * mDensity;
mIndexbarMargin = 10 * 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.size() > 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.get(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.get(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.size();
float paddingTop = (sectionHeight - (indexPaint.descent() - indexPaint.ascent())) / 2;
for (int i = 0; i < mSections.size(); i++) {
float paddingLeft = (mIndexbarWidth - indexPaint.measureText(mSections.get(i))) / 2;
canvas.drawText(mSections.get(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());
recyclerView.scrollToPosition(mSectionPosition.get(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());
recyclerView.scrollToPosition(mSectionPosition.get(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);
}
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;
}
}
public 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.size() == 0)
return 0;
if (y < mIndexbarRect.top + mIndexbarMargin)
return 0;
if (y >= mIndexbarRect.top + mIndexbarRect.height() - mIndexbarMargin)
return mSections.size() - 1;
return (int) ((y - mIndexbarRect.top - mIndexbarMargin) / ((mIndexbarRect.height() - 2 * mIndexbarMargin) / mSections.size()));
}
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);
}
recyclerView.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);
}
recyclerView.invalidate();
fade(10);
break;
}
}
};
public void notifyChanges(List<String> sectionName, List<Integer> sectionPosition) {
// Pre-calculate and pass your section header and position
mSections = sectionNames;
mSectionPosition = sectionPosition;
}}
这只是我修改以测试它的快速修复。似乎对我有用，有 3100 个项目的列表。当您将 Items 设置为适配器时，您需要计算节标题和位置。在我的情况下，我遍历我的预排序列表并为每个字符获取第一项的位置并放入一个列表并传递给公共 void notifyChanges(List sectionName, List sectionPosition)。希望能帮助到你。