Android 类似UC浏览器的效果：向上滑动地址栏隐藏功能

<?xml version="1.0" encoding="utf-8"?><RelativeLayout android:id="@+id/root" 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" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"> <samples.zjc.com.testbrowserfeature.MyScrollView  android:id="@+id/scrollView"  android:scrollbars="none"  android:layout_width="match_parent"  android:layout_height="match_parent">  <LinearLayout   android:orientation="vertical"   android:layout_width="match_parent"   android:layout_height="match_parent">   <LinearLayout    android:id="@+id/toolBar"    android:background="#5ff0"    android:orientation="horizontal"    android:layout_width="match_parent"    android:layout_height="wrap_content">    <EditText     android:id="@+id/urlEdit"     android:layout_weight="1"     android:layout_width="0dp"     android:layout_height="wrap_content"/>    <Button     android:id="@+id/goButton"     android:text="Go"     android:layout_width="wrap_content"     android:layout_height="wrap_content"/>   </LinearLayout>   <samples.zjc.com.testbrowserfeature.MyWebView    android:id="@+id/webView"    android:layout_width="match_parent"    android:layout_height="100dp" />  </LinearLayout> </samples.zjc.com.testbrowserfeature.MyScrollView></RelativeLayout>

onTouchEvent 中阻止 MotionEvent.ACTION_MOVE 事件public class MyScrollView extends ScrollView { public MyScrollView(Context context) {  super(context); } public MyScrollView(Context context, AttributeSet attrs) {  super(context, attrs); } public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr) {  super(context, attrs, defStyleAttr); } @TargetApi(Build.VERSION_CODES.LOLLIPOP) public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {  super(context, attrs, defStyleAttr, defStyleRes); } @Override public boolean onTouchEvent(MotionEvent ev) {  if(ev.getAction() == MotionEvent.ACTION_MOVE) {   return true;  }  return super.onTouchEvent(ev); }}

public class MyWebView extends WebView { public interface MyWebViewListener {  void afterDraw(WebView webView); } private MyWebViewListener mListener; private int mMoveCheckedCnt; public MyWebView(Context context) {  super(context); } public MyWebView(Context context, AttributeSet attrs) {  super(context, attrs); } public MyWebView(Context context, AttributeSet attrs, int defStyleAttr) {  super(context, attrs, defStyleAttr); } @TargetApi(Build.VERSION_CODES.LOLLIPOP) public MyWebView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {  super(context, attrs, defStyleAttr, defStyleRes); } public MyWebView(Context context, AttributeSet attrs, int defStyleAttr, boolean privateBrowsing) {  super(context, attrs, defStyleAttr, privateBrowsing); } public void setListener(MyWebViewListener listener) {  mListener = listener; } @Override public boolean onTouchEvent(MotionEvent event) {  switch (event.getAction()) {   case MotionEvent.ACTION_DOWN:    mMoveCheckedCnt = 0;    flingScroll(0, 0);    break;   case MotionEvent.ACTION_MOVE:    mMoveCheckedCnt++;    return false;   case MotionEvent.ACTION_UP:    if(mMoveCheckedCnt >= 2) {     event.setAction(MotionEvent.ACTION_CANCEL);     mMoveCheckedCnt = 0;    }    break;  }  return super.onTouchEvent(event); } @Override protected void onDraw(Canvas canvas) {  super.onDraw(canvas);  MyWebViewListener listener = mListener;  if(listener != null) {   listener.afterDraw(this);  } } public int getVScrollRange() {  int v = computeVerticalScrollRange() - computeVerticalScrollExtent();  if(v < 0) {   v = 0;  }  return v; }}

public class MainActivity extends AppCompatActivity implements MyWebView.MyWebViewListener { MyWebView mWebView; GestureDetector mGesture = null; View mToolBar; int mToolBarHeight; MyScrollView mScrollView; int mScrollViewHeight; int mScrollOffset; EditText mUrlEdit; @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);  mWebView = (MyWebView) findViewById(R.id.webView);  mWebView.setWebViewClient(new WebViewClient() {   @Override   public boolean shouldOverrideUrlLoading(WebView view, String url) {    return false;   }  });  mWebView.setListener(this);  mWebView.loadUrl("http://www.sohu.com");  mUrlEdit = (EditText) findViewById(R.id.urlEdit);  findViewById(R.id.goButton).setOnClickListener(new View.OnClickListener() {   @Override   public void onClick(View v) {    String url = mUrlEdit.getText().toString();    if (!url.startsWith("http://") && !url.startsWith("https://")) {     url = "http://" + url;    }    mWebView.loadUrl(url);   }  });  mToolBar = findViewById(R.id.toolBar);  mScrollView = (MyScrollView)findViewById(R.id.scrollView);  ScrollView scrollView = (ScrollView) mScrollView;  findViewById(R.id.root).getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {   @Override   public void onGlobalLayout() {    mToolBarHeight = mToolBar.getHeight();    mScrollViewHeight = mScrollView.getHeight();    adjustScrollView();   }  });  mGesture = new GestureDetector(this, new GestureListener()); } @Override public boolean dispatchTouchEvent(MotionEvent ev) {  mGesture.onTouchEvent(ev);  return super.dispatchTouchEvent(ev); } @Override public void afterDraw(WebView webView) {  if (mWebView.getVScrollRange() < mScrollOffset) {   mScrollOffset = mWebView.getVScrollRange();   adjustScrollView();  } } class GestureListener extends GestureDetector.SimpleOnGestureListener {  @Override  public boolean onDoubleTap(MotionEvent e) {   Log.e("Temp", "onDoubleTap");   return super.onDoubleTap(e);  }  @Override  public boolean onDown(MotionEvent e) {   Log.e("Temp", "onDown");   return super.onDown(e);  }  @Override  public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,        float velocityY) {   Log.e("Temp", "onFling:velocityX = " + velocityX + " velocityY" + velocityY);   int effectX = (int) velocityX;   int effectY = (int) velocityY;   if (effectOnScrollViewByScroll((velocityY < 0 ? 1 : -1) * 8000)) {    effectY = 0;   }   mWebView.flingScroll(-effectX, -effectY);   return super.onFling(e1, e2, velocityX, velocityY);  }  @Override  public void onLongPress(MotionEvent e) {   Log.e("Temp", "onLongPress");   super.onLongPress(e);  }  @Override  public boolean onScroll(MotionEvent e1, MotionEvent e2,        float distanceX, float distanceY) {   Log.e("Temp", "onScroll:distanceX = " + distanceX + " distanceY = " + distanceY);   int effectX = (int) distanceX;   int effectY = (int) distanceY;   if (effectOnScrollViewByScroll((int) distanceY)) {    effectY = 0;   }   mWebView.scrollBy(effectX, effectY);   return super.onScroll(e1, e2, distanceX, distanceY);  }  @Override  public boolean onSingleTapUp(MotionEvent e) {   Log.e("Temp", "onSingleTapUp");   return super.onSingleTapUp(e);  } } private boolean effectOnScrollViewByScroll(int distanceY) {  if (distanceY > 0) {   // scroll up, the web will scroll down   if (mScrollOffset >= mToolBarHeight || mScrollOffset >= mWebView.getVScrollRange()) {    return false;   }   mScrollOffset += distanceY;   if (mScrollOffset > mToolBarHeight) {    mScrollOffset = mToolBarHeight;   }   if (mScrollOffset > mWebView.getVScrollRange()) {    mScrollOffset = mWebView.getVScrollRange();   }  } else {   if (mScrollOffset <= 0) {    return false;   }   mScrollOffset += distanceY;   if (mScrollOffset <= 0) {    mScrollOffset = 0;   }  }  adjustScrollView();  return true; } private void adjustScrollView() {  Log.e("Temp", "offset is " + mScrollOffset);  ViewGroup.LayoutParams layoutParams = mWebView.getLayoutParams();  int newHeight = (mScrollViewHeight - mToolBarHeight) + mScrollOffset;  Log.e("Temp", "newHeight is " + newHeight + ", layoutParams.height" + layoutParams.height);  if (newHeight != layoutParams.height) {   layoutParams.height = newHeight;   mWebView.setLayoutParams(layoutParams);   new Handler(Looper.getMainLooper()).post(new Runnable() {    @Override    public void run() {     mScrollView.fullScroll(ScrollView.FOCUS_DOWN);    }   });  } }}