问题
I've got an activity that use WebView to load the web content. The problem arise when I want to implement Flexible Space with image. I can expand and collapse the Toolbar, but when the Toolbar already collapsed, The scrollbar stuck there. I can't scroll the content inside the WebView.
This is the XML:
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipToPadding="false"
android:fillViewport="true"
app:layout_behavior="@string/appbar_scrolling_view_behavior">
<WebView
android:id="@+id/read_full_content_wv"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</android.support.v4.widget.NestedScrollView>
Do you have any solution for this?
Regards, Elmer
EDIT After I look at the link that given by LinX64. I tried to add:
public class FullContentActivity extends AppCompatActivity {
...
@Override
protected void onCreate(Bundle savedInstance){
...
WebView webView = (WebView) findViewById(R.id.read_full_content_wv);
webView.setWebViewClient(new MyBrowser());
webView.loadData(extra.get(1).toString(), "text/html", "utf-8");
...
}
...
private class MyBrowser extends WebViewClient {
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon){
NestedScrollView nsv = (NestedScrollView) findViewById(R.id.nsv_fc);
nsv.scrollTo(0,0);
}
}
}
and still got stucked.
EDIT 2 FYI: I tried on ASUS Zenfone 6 - KitKat 4.4.2 Is it possible KitKat can't load it correctly?
EDIT 3: The best solution I've got for this question
After working around, I think I cannot get experience I want for Flexible Space using CollapsingToolbarLayout combined with WebView, so I changed WebView to TextView and use Html.fromHtml() to read the content. Unless Google gonna update or fix some features so we can combine CollapsingToolbarLayout and WebView together.
回答1:
By the usage of NestedScrollingChild Interface, we can implements the NestedScrollView properties in the webview. And customize the scrolling functionality under the onTouchEvent() method.
public class NestedWebView extends WebView implements NestedScrollingChild {
private int mLastY;
private final int[] mScrollOffset = new int[2];
private final int[] mScrollConsumed = new int[2];
private int mNestedOffsetY;
private NestedScrollingChildHelper mChildHelper;
public NestedWebView(Context context) {
this(context, null);
}
public NestedWebView(Context context, AttributeSet attrs) {
this(context, attrs, android.R.attr.webViewStyle);
}
public NestedWebView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
mChildHelper = new NestedScrollingChildHelper(this);
setNestedScrollingEnabled(true);
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
boolean returnValue = false;
MotionEvent event = MotionEvent.obtain(ev);
final int action = MotionEventCompat.getActionMasked(event);
if (action == MotionEvent.ACTION_DOWN) {
mNestedOffsetY = 0;
}
int eventY = (int) event.getY();
event.offsetLocation(0, mNestedOffsetY);
switch (action) {
case MotionEvent.ACTION_MOVE:
int totalScrollOffset = 0;
int deltaY = mLastY - eventY;
// NestedPreScroll
if (dispatchNestedPreScroll(0, deltaY, mScrollConsumed, mScrollOffset)) {
totalScrollOffset += mScrollOffset[1];
deltaY -= mScrollConsumed[1];
event.offsetLocation(0, -mScrollOffset[1]);
mNestedOffsetY += mScrollOffset[1];
}
returnValue = super.onTouchEvent(event);
// NestedScroll
if (dispatchNestedScroll(0, mScrollOffset[1], 0, deltaY, mScrollOffset)) {
totalScrollOffset += mScrollOffset[1];
event.offsetLocation(0, mScrollOffset[1]);
mNestedOffsetY += mScrollOffset[1];
mLastY -= mScrollOffset[1];
}
mLastY = eventY - totalScrollOffset;
break;
case MotionEvent.ACTION_DOWN:
returnValue = super.onTouchEvent(event);
mLastY = eventY;
// start NestedScroll
startNestedScroll(ViewCompat.SCROLL_AXIS_VERTICAL);
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
returnValue = super.onTouchEvent(event);
// end NestedScroll
stopNestedScroll();
break;
}
return returnValue;
}
// Nested Scroll implements
@Override
public void setNestedScrollingEnabled(boolean enabled) {
mChildHelper.setNestedScrollingEnabled(enabled);
}
@Override
public boolean isNestedScrollingEnabled() {
return mChildHelper.isNestedScrollingEnabled();
}
@Override
public boolean startNestedScroll(int axes) {
return mChildHelper.startNestedScroll(axes);
}
@Override
public void stopNestedScroll() {
mChildHelper.stopNestedScroll();
}
@Override
public boolean hasNestedScrollingParent() {
return mChildHelper.hasNestedScrollingParent();
}
@Override
public boolean dispatchNestedScroll(int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed,
int[] offsetInWindow) {
return mChildHelper.dispatchNestedScroll(dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, offsetInWindow);
}
@Override
public boolean dispatchNestedPreScroll(int dx, int dy, int[] consumed, int[] offsetInWindow) {
return mChildHelper.dispatchNestedPreScroll(dx, dy, consumed, offsetInWindow);
}
@Override
public boolean dispatchNestedFling(float velocityX, float velocityY, boolean consumed) {
return mChildHelper.dispatchNestedFling(velocityX, velocityY, consumed);
}
@Override
public boolean dispatchNestedPreFling(float velocityX, float velocityY) {
return mChildHelper.dispatchNestedPreFling(velocityX, velocityY);
}
}
Declare NestedWebView instead of declaring webview inside the NestedScrollView.For example,
<com.nestedscrollwebviewexample.NestedWebView
android:id="@+id/nested_webview"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#000000"
android:fillViewport="true"
android:focusable="true"
android:isScrollContainer="false"
android:visibility="visible"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
app:layout_scrollFlags="scroll|exitUntilCollapsed" />
Instead of declaring Webview you can initialize as NestedWebView inside your Activity
private NestedWebView mShopWebView;
mShopWebView = (NestedWebView) findViewById(R.id.url_load_webview);
回答2:
Got this one working with changing the height attribute of the underlying Webview.
For NestedScrollView use attribute
android:fillViewport="true"
and for WebView use android:layout_height="wrap_content"
Full Answer here
回答3:
I faced a similar problem but I solved it on multiple Android versions by using the following custom WebView class which manages the touch events:
import android.content.Context;
import android.support.v4.view.MotionEventCompat;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.webkit.WebView;
/**
* Created by pk on 10/16/16.
* Creates a WebView that can be used inside a ScrollView
*/
public class CustomWebView extends WebView {
public CustomWebView(Context context) {
super(context);
}
public CustomWebView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public CustomWebView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
//Check pointer index to avoid -1 (error)
if (MotionEventCompat.findPointerIndex(event, 0) == -1) {
return super.onTouchEvent(event);
}
if (event.getPointerCount() >= 2) {
requestDisallowInterceptTouchEvent(true);
} else {
requestDisallowInterceptTouchEvent(false);
}
return super.onTouchEvent(event);
}
@Override
protected void onOverScrolled(int scrollX, int scrollY, boolean clampedX, boolean clampedY) {
super.onOverScrolled(scrollX, scrollY, clampedX, clampedY);
requestDisallowInterceptTouchEvent(true);
}
}
回答4:
I see it's been awhile, but i'll try anyway
I had a similar problem.
I solved it by replacing: android.support.v4.widget.NestedScrollView with: android.widget.ScrollView I don't know how it will affect on the collapsing toolbar.
来源：https://stackoverflow.com/questions/35127845/webview-inside-nestedscrollview-cannot-be-scrolled