Qt for Android

Qt for Android enables you to run Qt 5 applications Android devices. All Qt modules (essential and add-on) are supported except Qt WebEngine, Qt Serial Port, and the platform-specific ones (Qt Mac Extras, Qt Windows Extras, and Qt X11 Extras).

在Windows或者Linux平台上可以用QtWebEngine模块实现网页预览和打印成PDF文档，用起来很方便，生成的文档质量也比较好，但在Android平台上QtWebEngine模块不能用，想要显示网页可以用QtWebView模块，不支持打印成PDF。尝试用QTextDocument和QPrinter将html转为PDF，发现QTextDocument不支持CSS样式，生成的PDF文档排版是错的。

查看QtWebView在Android平台上的实现，可以发现其用的就是Android的WebView控件实现的网页显示。尝试在Android平台上实现html生成PDF，找到了这篇文章https://www.jianshu.com/p/d82bd61b11a4，验证后可行。需要依赖第三方库DexMaker，可以用谷歌实现的 implementation 'com.google.dexmaker:dexmaker:1.2'，库文件名为dexmaker-1.2.jar。

修改QT源码，在Android平台上实现html转PDF的功能

修改$QtSrc/qtwebview/src/jar/src/org/qtproject/qt5/android/view/QtAndroidWebViewController.java文件

/******************************************************************************** Copyright (C) 2015 The Qt Company Ltd.** Contact: http://www.qt.io/licensing/**** This file is part of the QtWebView module of the Qt Toolkit.**** $QT_BEGIN_LICENSE:LGPL3$** Commercial License Usage** Licensees holding valid commercial Qt licenses may use this file in** accordance with the commercial license agreement provided with the** Software or, alternatively, in accordance with the terms contained in** a written agreement between you and The Qt Company. For licensing terms** and conditions see http://www.qt.io/terms-conditions. For further** information use the contact form at http://www.qt.io/contact-us.**** GNU Lesser General Public License Usage** Alternatively, this file may be used under the terms of the GNU Lesser** General Public License version 3 as published by the Free Software** Foundation and appearing in the file LICENSE.LGPLv3 included in the** packaging of this file. Please review the following information to** ensure the GNU Lesser General Public License version 3 requirements** will be met: https://www.gnu.org/licenses/lgpl.html.**** GNU General Public License Usage** Alternatively, this file may be used under the terms of the GNU** General Public License version 2.0 or later as published by the Free** Software Foundation and appearing in the file LICENSE.GPL included in** the packaging of this file. Please review the following information to** ensure the GNU General Public License version 2.0 requirements will be** met: http://www.gnu.org/licenses/gpl-2.0.html.**** $QT_END_LICENSE$******************************************************************************/package org.qtproject.qt5.android.view;import android.content.pm.PackageManager;import android.view.View;import android.webkit.GeolocationPermissions;import android.webkit.URLUtil;import android.webkit.ValueCallback;import android.annotation.SuppressLint;import android.content.Context;import android.os.Bundle;import android.os.CancellationSignal;import android.os.ParcelFileDescriptor;import android.print.PageRange;import android.print.PrintAttributes;import android.print.PrintDocumentAdapter;import android.webkit.WebView;import android.webkit.WebViewClient;import android.webkit.WebChromeClient;import java.lang.Runnable;import android.app.Activity;import android.content.Intent;import android.net.Uri;import java.lang.String;import android.webkit.WebSettings;import android.webkit.WebSettings.PluginState;import android.graphics.Bitmap;import java.util.concurrent.Semaphore;import java.io.File;import java.io.IOException;import java.lang.reflect.InvocationHandler;import java.lang.reflect.Method;import android.os.Build;import java.util.concurrent.TimeUnit;import com.google.dexmaker.stock.ProxyBuilder;public class QtAndroidWebViewController{    private final Activity m_activity;    private final long m_id;    private boolean busy;    private boolean m_hasLocationPermission;    private WebView m_webView = null;    private static final String TAG = "QtAndroidWebViewController";    private final int INIT_STATE = 0;    private final int STARTED_STATE = 1;    private final int LOADING_STATE = 2;    private final int FINISHED_STATE = 3;    private volatile int m_loadingState = INIT_STATE;    private volatile int m_progress = 0;    private volatile int m_frameCount = 0;    // API 11 methods    private Method m_webViewOnResume = null;    private Method m_webViewOnPause = null;    private Method m_webSettingsSetDisplayZoomControls = null;    // API 19 methods    private Method m_webViewEvaluateJavascript = null;    // Native callbacks    private native void c_onPageFinished(long id, String url);    private native void c_onPageStarted(long id, String url, Bitmap icon);    private native void c_onProgressChanged(long id, int newProgress);    private native void c_onReceivedIcon(long id, Bitmap icon);    private native void c_onReceivedTitle(long id, String title);    private native void c_onRunJavaScriptResult(long id, long callbackId, String result);    private native void c_onReceivedError(long id, int errorCode, String description, String url);    private native void c_onpdfPrintingFinished(long id, boolean succeed);    // We need to block the UI thread in some cases, if it takes to long we should timeout before    // ANR kicks in... Usually the hard limit is set to 10s and if exceed that then we're in trouble.    // In general we should not let input events be delayed for more then 500ms (If we're spending more    // then 200ms somethings off...).    private final long BLOCKING_TIMEOUT = 250;    private void resetLoadingState(final int state)    {        m_progress = 0;        m_frameCount = 0;        m_loadingState = state;    }    private class Html2Pdf {        private File file;        private File dexCacheFile;        private PrintDocumentAdapter printAdapter;        private PageRange[] ranges;        private ParcelFileDescriptor descriptor;            private void printToPdf(WebView webView, String fileName) {            if (webView != null) {                file = new File(fileName);                dexCacheFile = webView.getContext().getDir("dex", 0);                if (!dexCacheFile.exists()) {                    dexCacheFile.mkdir();                }                try {                    if (file.exists()) {                        file.delete();                    }                    file.createNewFile();                    descriptor = ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_WRITE);                    PrintAttributes attributes = new PrintAttributes.Builder()                            .setMediaSize(PrintAttributes.MediaSize.ISO_A4)                            .setResolution(new PrintAttributes.Resolution("id", Context.PRINT_SERVICE, 300, 300))                            .setColorMode(PrintAttributes.COLOR_MODE_COLOR)                            .setMinMargins(PrintAttributes.Margins.NO_MARGINS)                            .build();                    ranges = new PageRange[]{PageRange.ALL_PAGES};                        printAdapter = webView.createPrintDocumentAdapter();                    printAdapter.onStart();                    printAdapter.onLayout(attributes, attributes, new CancellationSignal(), getLayoutResultCallback(new InvocationHandler() {                        @Override                        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {                            if (method.getName().equals("onLayoutFinished")) {                                onLayoutSuccess();                            } else {                                descriptor.close();                                c_onpdfPrintingFinished(m_id, false);                                busy = false;                            }                            return null;                        }                    }, dexCacheFile.getAbsoluteFile()), new Bundle());                } catch (IOException e) {                    if (descriptor != null) {                        try {                            descriptor.close();                        } catch (IOException ex) {                            ex.printStackTrace();                        }                    }                    c_onpdfPrintingFinished(m_id, false);                    e.printStackTrace();                    busy = false;                }            }        }            private void onLayoutSuccess() throws IOException {            PrintDocumentAdapter.WriteResultCallback callback = getWriteResultCallback(new InvocationHandler() {                @Override                public Object invoke(Object o, Method method, Object[] objects) throws Throwable {                    if (method.getName().equals("onWriteFinished")) {                        c_onpdfPrintingFinished(m_id, true);                    } else {                        c_onpdfPrintingFinished(m_id, false);                    }                    busy = false;                    if (descriptor != null) {                        try {                            descriptor.close();                        } catch (IOException ex) {                            ex.printStackTrace();                        }                    }                    return null;                }            }, dexCacheFile.getAbsoluteFile());            printAdapter.onWrite(ranges, descriptor, new CancellationSignal(), callback);        }            @SuppressLint("NewApi")        private  PrintDocumentAdapter.LayoutResultCallback getLayoutResultCallback(InvocationHandler invocationHandler, File dexCacheDir) throws IOException {            return ProxyBuilder.forClass(PrintDocumentAdapter.LayoutResultCallback.class)                    .dexCache(dexCacheDir)                    .handler(invocationHandler)                    .build();        }            @SuppressLint("NewApi")        private  PrintDocumentAdapter.WriteResultCallback getWriteResultCallback(InvocationHandler invocationHandler, File dexCacheDir) throws IOException {            return ProxyBuilder.forClass(PrintDocumentAdapter.WriteResultCallback.class)                    .dexCache(dexCacheDir)                    .handler(invocationHandler)                    .build();        }        }    private class QtAndroidWebViewClient extends WebViewClient    {        QtAndroidWebViewClient() { super(); }        @Override        public boolean shouldOverrideUrlLoading(WebView view, String url)        {            // handle http: and http:, etc., as usual            if (URLUtil.isValidUrl(url))                return false;            // try to handle geo:, tel:, mailto: and other schemes            try {                Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));                view.getContext().startActivity(intent);                return true;            } catch (Exception e) {                e.printStackTrace();            }            return false;        }        @Override        public void onLoadResource(WebView view, String url)        {            super.onLoadResource(view, url);        }        @Override        public void onPageFinished(WebView view, String url)        {            super.onPageFinished(view, url);            m_loadingState = FINISHED_STATE;            if (m_progress != 100) // onProgressChanged() will notify Qt if we didn't finish here.                return;             m_frameCount = 0;             c_onPageFinished(m_id, url);        }        @Override        public void onPageStarted(WebView view, String url, Bitmap favicon)        {            super.onPageStarted(view, url, favicon);            if (++m_frameCount == 1) { // Only call onPageStarted for the first frame.                m_loadingState = LOADING_STATE;                c_onPageStarted(m_id, url, favicon);            }        }        @Override        public void onReceivedError(WebView view,                                    int errorCode,                                    String description,                                    String url)        {            super.onReceivedError(view, errorCode, description, url);            resetLoadingState(INIT_STATE);            c_onReceivedError(m_id, errorCode, description, url);        }    }    private class QtAndroidWebChromeClient extends WebChromeClient    {        QtAndroidWebChromeClient() { super(); }        @Override        public void onProgressChanged(WebView view, int newProgress)        {            super.onProgressChanged(view, newProgress);            m_progress = newProgress;            c_onProgressChanged(m_id, newProgress);            if (m_loadingState == FINISHED_STATE && m_progress == 100) { // Did we finish?                m_frameCount = 0;                c_onPageFinished(m_id, view.getUrl());            }        }        @Override        public void onReceivedIcon(WebView view, Bitmap icon)        {            super.onReceivedIcon(view, icon);            c_onReceivedIcon(m_id, icon);        }        @Override        public void onReceivedTitle(WebView view, String title)        {            super.onReceivedTitle(view, title);            c_onReceivedTitle(m_id, title);        }        @Override        public void onGeolocationPermissionsShowPrompt(String origin, GeolocationPermissions.Callback callback)        {            callback.invoke(origin, m_hasLocationPermission, false);        }    }    public QtAndroidWebViewController(final Activity activity, final long id)    {        m_activity = activity;        m_id = id;        final Semaphore sem = new Semaphore(0);        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() {                m_webView = new WebView(m_activity);                m_hasLocationPermission = hasLocationPermission(m_webView);                WebSettings webSettings = m_webView.getSettings();                if (Build.VERSION.SDK_INT > 10) {                    try {                        m_webViewOnResume = m_webView.getClass().getMethod("onResume");                        m_webViewOnPause = m_webView.getClass().getMethod("onPause");                        m_webSettingsSetDisplayZoomControls = webSettings.getClass().getMethod("setDisplayZoomControls", boolean.class);                        if (Build.VERSION.SDK_INT > 18) {                            m_webViewEvaluateJavascript = m_webView.getClass().getMethod("evaluateJavascript",                                                                                         String.class,                                                                                         ValueCallback.class);                        }                    } catch (Exception e) { /* Do nothing */ e.printStackTrace(); }                }                //allowing access to location without actual ACCESS_FINE_LOCATION may throw security exception                webSettings.setGeolocationEnabled(m_hasLocationPermission);                webSettings.setJavaScriptEnabled(true);                if (m_webSettingsSetDisplayZoomControls != null) {                    try { m_webSettingsSetDisplayZoomControls.invoke(webSettings, false); } catch (Exception e) { e.printStackTrace(); }                }                webSettings.setBuiltInZoomControls(true);                webSettings.setPluginState(PluginState.ON);                m_webView.setWebViewClient((WebViewClient)new QtAndroidWebViewClient());                m_webView.setWebChromeClient((WebChromeClient)new QtAndroidWebChromeClient());                sem.release();            }        });        try {            sem.acquire();        } catch (Exception e) {            e.printStackTrace();        }    }    public void loadUrl(final String url)    {        if (url == null) {            return;        }        resetLoadingState(STARTED_STATE);        c_onPageStarted(m_id, url, null);        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() { m_webView.loadUrl(url); }        });    }    public void loadData(final String data, final String mimeType, final String encoding)    {        if (data == null)            return;        resetLoadingState(STARTED_STATE);        c_onPageStarted(m_id, null, null);        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() { m_webView.loadData(data, mimeType, encoding); }        });    }    public void loadDataWithBaseURL(final String baseUrl,                                    final String data,                                    final String mimeType,                                    final String encoding,                                    final String historyUrl)    {        if (data == null)            return;        resetLoadingState(STARTED_STATE);        c_onPageStarted(m_id, null, null);        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() { m_webView.loadDataWithBaseURL(baseUrl, data, mimeType, encoding, historyUrl); }        });    }    public void goBack()    {        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() { m_webView.goBack(); }        });    }    public boolean canGoBack()    {        final boolean[] back = {false};        final Semaphore sem = new Semaphore(0);        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() { back[0] = m_webView.canGoBack(); sem.release(); }        });        try {            sem.tryAcquire(BLOCKING_TIMEOUT, TimeUnit.MILLISECONDS);        } catch (Exception e) {            e.printStackTrace();        }        return back[0];    }    public void goForward()    {        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() { m_webView.goForward(); }        });    }    public boolean canGoForward()    {        final boolean[] forward = {false};        final Semaphore sem = new Semaphore(0);        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() { forward[0] = m_webView.canGoForward(); sem.release(); }        });        try {            sem.tryAcquire(BLOCKING_TIMEOUT, TimeUnit.MILLISECONDS);        } catch (Exception e) {            e.printStackTrace();        }        return forward[0];    }    public void stopLoading()    {        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() { m_webView.stopLoading(); }        });    }    public void reload()    {        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() { m_webView.reload(); }        });    }    public String getTitle()    {        final String[] title = {""};        final Semaphore sem = new Semaphore(0);        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() { title[0] = m_webView.getTitle(); sem.release(); }        });        try {            sem.tryAcquire(BLOCKING_TIMEOUT, TimeUnit.MILLISECONDS);        } catch (Exception e) {            e.printStackTrace();        }        return title[0];    }    public int getProgress()    {        return m_progress;    }    public boolean isLoading()    {        return m_loadingState == LOADING_STATE || m_loadingState == STARTED_STATE || (m_progress > 0 && m_progress < 100);    }    public void runJavaScript(final String script, final long callbackId)    {        if (script == null)            return;        if (Build.VERSION.SDK_INT < 19 || m_webViewEvaluateJavascript == null)            return;        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() {                try {                    m_webViewEvaluateJavascript.invoke(m_webView, script, callbackId == -1 ? null :                        new ValueCallback() {                            @Override                            public void onReceiveValue(String result) {                                c_onRunJavaScriptResult(m_id, callbackId, result);                            }                        });                } catch (Exception e) {                    e.printStackTrace();                }            }        });    }    public String getUrl()    {        final String[] url = {""};        final Semaphore sem = new Semaphore(0);        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() { url[0] = m_webView.getUrl(); sem.release(); }        });        try {            sem.tryAcquire(BLOCKING_TIMEOUT, TimeUnit.MILLISECONDS);        } catch (Exception e) {            e.printStackTrace();        }        return url[0];    }    public WebView getWebView()    {       return m_webView;    }    public void onPause()    {        if (m_webViewOnPause == null)            return;        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() { try { m_webViewOnPause.invoke(m_webView); } catch (Exception e) { e.printStackTrace(); } }        });    }    public void onResume()    {        if (m_webViewOnResume == null)            return;        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() { try { m_webViewOnResume.invoke(m_webView); } catch (Exception e) { e.printStackTrace(); } }        });    }    private static boolean hasLocationPermission(View view)    {        final String name = view.getContext().getPackageName();        final PackageManager pm = view.getContext().getPackageManager();        return pm.checkPermission("android.permission.ACCESS_FINE_LOCATION", name) == PackageManager.PERMISSION_GRANTED;    }    public void destroy()    {        m_activity.runOnUiThread(new Runnable() {            @Override            public void run() {                m_webView.destroy();            }        });    }    public void printToPdf(final String fileName){        if(!busy){            busy = true;            m_activity.runOnUiThread(new Runnable() {                @Override                public void run() {                     Html2Pdf html2Pdf = new Html2Pdf();                    html2Pdf.printToPdf(m_webView, fileName);                }            });        }else{            c_onpdfPrintingFinished(m_id,false);         }    }}

主要修改：
1. 增加了 void printToPdf(final String fileName)打印接口
2. 增加了 native void c_onpdfPrintingFinished(long id, boolean succeed)作为打印完成的回调
3. 增加了内部类Html2Pdf实现打印成PDF

修改$QtSrc/qtwebview/src/plugins/android/qandroidwebview_p.h

增加槽函数 void printToPdf(const QString &fileName) Q_DECL_OVERRIDE;

修改$QtSrc/qtwebview/src/plugins/android/qandroidwebview.cpp

实现槽函数

void QAndroidWebViewPrivate::printToPdf(const QString &fileName){    const QJNIObjectPrivate &fileNameString = QJNIObjectPrivate::fromString(fileName);    m_viewController.callMethod<void>("printToPdf","(Ljava/lang/String;)V",fileNameString.object());}

实现java代码中打印完成的回调

static void c_onpdfPrintingFinished(JNIEnv *env,                              jobject thiz,                              jlong id,                              jboolean succeed){    Q_UNUSED(env)    Q_UNUSED(thiz)    const WebViews &wv = (*g_webViews);    QAndroidWebViewPrivate *wc = wv[id];    if (!wc)        return;    Q_EMIT wc->pdfPrintingFinished(succeed);}

修改JNIEXPORT jint JNI_OnLoad(JavaVM* vm, void* /*reserved*/)，注册c_onpdfPrintingFinished回调函数。

JNINativeMethod methods[]数组里增加一项{"c_onpdfPrintingFinished","(JZ)V",reinterpret_cast<void *>(c_onpdfPrintingFinished)}

修改$QtSrc/qtwebview/src/webview/qabstractwebview_p.h（以下增加的所有的C++代码、函数、信号等都用#if ANDROID宏条件编译）

增加信号void pdfPrintingFinished(bool succeed);

修改$QtSrc/qtwebview/src/webview/qquickwebview_p.h

增加公开槽函数 void printToPdf(const QString &fileName) Q_DECL_OVERRIDE;
增加信号 void pdfPrintingFinished(bool succeed);
增加私有槽函数 void onPdfPrintingFinished(bool succeed);

修改$QtSrc/qtwebview/src/webview/qquickwebview.cpp

构造函数里关联槽函数和信号

#if ANDROIDconnect(m_webView, &QWebView::pdfPrintingFinished, this, &QQuickWebView::onPdfPrintingFinished);#endif

实现槽函数printToPdf

#if ANDROIDvoid QQuickWebView::printToPdf(const QString &fileName){    m_webView->printToPdf(fileName);}#endif

实现槽函数onPdfPrintingFinished

#if ANDROIDvoid QQuickWebView::onPdfPrintingFinished(bool succeed){    Q_EMIT pdfPrintingFinished(succeed);}#endif

修改$QtSrc/qtwebview/src/webview/qwebviewinterface_p.h

增加纯虚函数 virtual void printToPdf(const QString &fileName) = 0;

修改$QtSrc/qtwebview/src/webview/qwebviewfactory.cpp

QNullWebView类增加

void printToPdf(const QString &fileName) override    {Q_UNUSED(fileName); }

修改$QtSrc/qtwebview/src/webview/qwebview_p.h

增加公开槽函数 void printToPdf(const QString &fileName) Q_DECL_OVERRIDE;
增加信号 void pdfPrintingFinished(bool succeed);
增加私有槽函数 void onPdfPrintingFinished(bool succeed);

修改$QtSrc/qtwebview/src/webview/qwebview.cpp

构造函数里关联槽函数和信号

#if ANDROIDconnect(d, &QAbstractWebView::pdfPrintingFinished, this, &QWebView::onPdfPrintingFinished);#endif

实现槽函数printToPdf

#if ANDROIDvoid QWebView::printToPdf(const QString &fileName){    d->printToPdf(fileName);}#endif

实现槽函数onPdfPrintingFinished

#if ANDROIDvoid QWebView::onPdfPrintingFinished(bool succeed){    Q_EMIT pdfPrintingFinished(succeed);}#endif

在$QtSrc/qtwebview/src/jar目录下新建lib目录，将dexmaker-1.2.jar文件拷贝到该目录下

修改$QtSrc/qtwebview/src/jar/jar.pro

TARGET = QtAndroidWebView

load(qt_build_paths)
CONFIG += java
DESTDIR = $$MODULE_BASE_OUTDIR/jar

JAVACLASSPATH += $$PWD/src \
    $$PWD/lib/dexmaker-1.2.jar

JAVASOURCES += $$PWD/src/org/qtproject/qt5/android/view/QtAndroidWebViewController.java

# install
thridpartyjar.files = \
    $$PWD/lib/dexmaker-1.2.jar
thridpartyjar.path = $$[QT_INSTALL_PREFIX]/jar

target.path = $$[QT_INSTALL_PREFIX]/jar
INSTALLS += target thridpartyjar

修改$QtSrc/qtwebview/src/webview/webview.pro

……QMAKE_DOCS = \
             $$PWD/doc/qtwebview.qdocconf

ANDROID_BUNDLED_JAR_DEPENDENCIES = \
    jar/QtAndroidWebView.jar \
    jar/dexmaker-1.2.jar
ANDROID_PERMISSIONS = \
    android.permission.ACCESS_FINE_LOCATION
ANDROID_LIB_DEPENDENCIES = \
    plugins/webview/libqtwebview_android.so

HEADERS += $$PUBLIC_HEADERS $$PRIVATE_HEADERS

load(qt_module)

修改$QtSrc/qtwebview/src/imports/plugins.qmltypes

增加信号

Signal {            name: "pdfPrintingFinished"            revision: 1            Parameter { name: "succeed"; type: "bool" }        }

增加方法

Method {            name: "printToPdf"            revision: 1            Parameter { name: "fileName"; type: "string" }        }

配置和编译

./configure -extprefix $QTInstall/android_arm64_v8a -xplatform android-clang -release -nomake tests -nomake examples -opensource -confirm-license -recheck-all -android-ndk $NDKPATH -android-sdk $AndroidSDKPATH -android-ndk-host linux-x86_64 -android-arch arm64-v8a

-android-arch支持armeabi, armeabi-v7a, arm64-v8a, x86, x86_64，一次只能编译一个架构，注意不同架构要修改安装目录

make -j8
make install

上述软件版本

QT：5.13.2
NDK：r20b(20.1.5948944)
Android-buildToolsVersion：29.0.2

使用示例

import QtQuick 2.12import QtQuick.Window 2.12import QtWebView 1.1import QtQuick.Controls 2.12Window {    id: window    visible: true    width: 1080    height: 1920    title: qsTr("Hello World")    WebView{        id:webView        anchors.bottom: printBtn.top        anchors.right: parent.right        anchors.left: parent.left        anchors.top: parent.top        anchors.bottomMargin: 0        url:"http://www.qq.com"        onPdfPrintingFinished: {            printBtn.text = "打印" + (succeed?"成功":"失败")            printBtn.enabled = true        }    }    Button {        id:printBtn        text: "打印"        anchors.bottom: parent.bottom        anchors.bottomMargin: 0        onClicked: {            printBtn.enabled = false            webView.printToPdf("/sdcard/aaa.pdf")        }    }}

全部修改见https://github.com/ALittleDruid/qtwebview/commit/722a4757dd0acf86846194607a433cd724e9b028

下期预告：在Android平台上实现串口读写的功能

Qt在Android平台上实现html转PDF的功能

Qt for Android

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