大家好我正在创建epub阅读器并在android webview中加载这本书 并使webview水平移动引用this 但现在我想让webview像页面一样移动所以我想这样做 1.计算总水平线宽度和屏幕宽度，现在将它们除以得到总页数 2.锁定webview的滚动，当用户滑动时，将webview的滚动设置为screenwidth * swipeCount
现在的问题是，当我试图获得totalHorizontalScrollWidth它给出了屏幕宽度我尝试了这些方法，但都给出了相同的结果
FirstMethod
ViewTreeObserver vto = webView.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
webView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
Log.e("ScrollWidth",""+webView.getMeasuredWidth());
Toast.makeText(getApplicationContext(), "new Width is"+webView.getMeasuredWidth(), Toast.LENGTH_SHORT).show();
}
});
返回480个屏幕宽度
和SecondMethod
public class WebViewWidth extends WebView {
public WebViewWidth(Context context) {
super(context);
}
public WebViewWidth(Context context, AttributeSet attrs) {
super(context, attrs);
}
public int getContentWidth()
{
return this.computeHorizontalScrollRange();
}
public int getContentHeight()
{
return this.computeVerticalScrollRange();
}
}
并使用此webView获取此类
的computeHorizontalScrollRangeprivate class MyWebViewClient extends WebViewClient {
private Context mContext;
public MyWebViewClient(Context context) {
this.mContext = context;
}
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
return true;
}
@Override
public void onPageFinished(WebView view, String url) {
mProgressDialog.dismiss();
final WebView myWebView = (WebView) view;
String varMySheet = "var mySheet = document.styleSheets[0];";
String addCSSRule = "function addCSSRule(selector, newRule) {"
+ "ruleIndex = mySheet.cssRules.length;"
+ "mySheet.insertRule(selector + '{' + newRule + ';}', ruleIndex);"
+ "}";
String insertRule1 = "addCSSRule('html', 'padding: 0px; height: "
+ (myWebView.getMeasuredHeight() / mContext.getResources().getDisplayMetrics().density)
+ "px; -webkit-column-gap: 0px; -webkit-column-width: "
+ myWebView.getMeasuredWidth() + "px;')";
myWebView.loadUrl("javascript:" + varMySheet);
myWebView.loadUrl("javascript:" + addCSSRule);
myWebView.loadUrl("javascript:" + insertRule1);
super.onPageFinished(view, url);
int widthis = webView.getContentWidth();
Toast.makeText(getApplicationContext(), "Width is"+widthis, Toast.LENGTH_SHORT).show();
Log.i("WidthTotoal Scroll", ""+widthis);
}
}
即便如此，结果为480，即屏幕尺寸
我也遇到过这个脚本，但不知道如何从这个脚本获取值到android
String js = ""+
"var desiredHeight;"+
" var desiredWidth;"+
" var bodyID = document.getElementsByTagName('body')[0];"+
" totalHeight = bodyID.offsetHeight;"+
"pageCount = Math.floor(totalHeight/desiredHeight) + 1;"+
" bodyID.style.padding = 10;"+ //(optional) prevents clipped letters around the edges
" bodyID.style.width = desiredWidth * pageCount;"+
" bodyID.style.height = desiredHeight;"+
" bodyID.style.WebkitColumnCount = pageCount;";
有人请帮助我获取webview的最大水平滚动宽度或某些替代方法以获得翻页效果。
答案 0 :(得分：2)
我想我已经很晚了但是感谢this我能够在WebView中实现平滑的水平滑动动画。
根据您的初始问题，想要获得html页面的总宽度，在我的解决方案中，我使用了 WebChromeClients onJsAlert（）方法，您可以在其中获取从javascript返回值。我使用这种方法来获取水平页面的数量。
在我的 MainActivity.java
中@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
WebView.setWebContentsDebuggingEnabled(true);
}
wv = (HorizontalWebView) findViewById(R.id.web_view);
wv.getSettings().setJavaScriptEnabled(true);
wv.setWebViewClient(new WebViewClient() {
public void onPageFinished(WebView view, String url) {
injectJavascript();
}
});
wv.setWebChromeClient(new WebChromeClient() {
@Override
public boolean onJsAlert(WebView view, String url, String message, JsResult result) {
int pageCount = Integer.parseInt(message);
wv.setPageCount(pageCount);
result.confirm();
return true;
}
});
wv.loadUrl("file:///android_asset/ch03.html");
}
private void injectJavascript() {
String js = "function initialize(){\n" +
" var d = document.getElementsByTagName('body')[0];\n" +
" var ourH = window.innerHeight;\n" +
" var ourW = window.innerWidth;\n" +
" var fullH = d.offsetHeight;\n" +
" var pageCount = Math.floor(fullH/ourH)+1;\n" +
" var currentPage = 0;\n" +
" var newW = pageCount*ourW;\n" +
" d.style.height = ourH+'px';\n" +
" d.style.width = newW+'px';\n" +
" d.style.margin = 0;\n" +
" d.style.webkitColumnCount = pageCount;\n" +
" return pageCount;\n" +
"}";
wv.loadUrl("javascript:" + js);
wv.loadUrl("javascript:alert(initialize())");
}
我使用 javascript：alert（initialize（））来执行javascript函数，其中我返回已创建的水平页面的数量。我传递给Custom WebView。
<强> HorizontalWebView.java
public class HorizontalWebView extends WebView {
private float x1 = -1;
private int pageCount = 0;
public HorizontalWebView(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
x1 = event.getX();
break;
case MotionEvent.ACTION_UP:
float x2 = event.getX();
float deltaX = x2 - x1;
if (Math.abs(deltaX) > 100) {
// Left to Right swipe action
if (x2 > x1) {
turnPageLeft();
return true;
}
// Right to left swipe action
else {
turnPageRight();
return true;
}
}
break;
}
return true;
}
private int current_x = 0;
private void turnPageLeft() {
if (getCurrentPage() > 0) {
int scrollX = getPrevPagePosition();
loadAnimation(scrollX);
current_x = scrollX;
scrollTo(scrollX, 0);
}
}
private int getPrevPagePosition() {
int prevPage = getCurrentPage() - 1;
return (int) Math.ceil(prevPage * this.getMeasuredWidth());
}
private void turnPageRight() {
if (getCurrentPage() < pageCount - 1) {
int scrollX = getNextPagePosition();
loadAnimation(scrollX);
current_x = scrollX;
scrollTo(scrollX, 0);
}
}
private void loadAnimation(int scrollX) {
ObjectAnimator anim = ObjectAnimator.ofInt(this, "scrollX",
current_x, scrollX);
anim.setDuration(500);
anim.setInterpolator(new LinearInterpolator());
anim.start();
}
private int getNextPagePosition() {
int nextPage = getCurrentPage() + 1;
return (int) Math.ceil(nextPage * this.getMeasuredWidth());
}
public int getCurrentPage() {
return (int) (Math.ceil((double) getScrollX() / this.getMeasuredWidth()));
}
public void setPageCount(int pageCount) {
this.pageCount = pageCount;
}
}
您可以找到完整的解决方案here
答案 1 :(得分：1)
我解决了这个问题，解决方案是保持倒数计时器并在计算宽度前给出1秒延迟
这是我怎么做的
@Override
public void onPageFinished(final WebView view, String url) {
final WebView myWebView = (WebView) view;
String varMySheet = "var mySheet = document.styleSheets[0];";
String addCSSRule = "function addCSSRule(selector, newRule) {"
+ "ruleIndex = mySheet.cssRules.length;"
+ "mySheet.insertRule(selector + '{' + newRule + ';}', ruleIndex);"
+ "}";
String insertRule1 = "addCSSRule('html', 'padding: 0px; height: "
+ (myWebView.getMeasuredHeight() / mContext.getResources().getDisplayMetrics().density)
+ "px; -webkit-column-gap: 0px; -webkit-column-width: "
+ myWebView.getMeasuredWidth() + "px;')";
String js = ""+
"var desiredHeight;"+
" var desiredWidth;"+
" var bodyID = document.getElementsByTagName('body')[0];"+
" totalHeight = bodyID.offsetHeight;"+
"pageCount = Math.floor(totalHeight/desiredHeight) + 1;"+
" bodyID.style.padding = 10;"+ //(optional) prevents clipped letters around the edges
" bodyID.style.width = desiredWidth * pageCount;"+
" bodyID.style.height = desiredHeight;"+
" bodyID.style.WebkitColumnCount = pageCount;"+
"function getPagesCount() {"+
" android.getPagesCount(pageCount);"+
" };";
myWebView.loadUrl("javascript:" + varMySheet);
myWebView.loadUrl("javascript:" + addCSSRule);
myWebView.loadUrl("javascript:" + insertRule1);
view.setVisibility(View.VISIBLE);
super.onPageFinished(view, url);
CountDownTimer test= new CountDownTimer(3000,1000) {
@Override
public void onTick(long millisUntilFinished) {
}
@Override
public void onFinish() {
int widthis = webView.getContentWidth();
TotalScrollWidth=widthis;
Log.i("WidthTotoal Scroll", ""+widthis);
TotalPages= (TotalScrollWidth/ScreenWidth)-1;
Toast.makeText(getApplicationContext(), "Total Pages are" +TotalPages, 100).show();
progressPages.setMax(TotalPages);
progressdialog.dismiss();
}
};
test.start();
}