问题
Please help me.,i m stuck with this for more than a week.I am emitting a signal with image from my cpp file.I need to replace the default image that i placed in the imageView at QMl using this emitted image. Here is my full code.
PostHttp.hpp
/* Copyright (c) 2012 Research In Motion Limited.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef POSTHTTP_HPP
#define POSTHTTP_HPP
#include "qvariant.h"
#include <bb/ImageData>
#include <bb/cascades/GroupDataModel>
#include <QtCore/QObject>
#include <bb/data/JsonDataAccess>
#include <bb/cascades/QListDataModel>
#include <bb/cascades/Image>
#include <bb/cascades/ImageView>
#include <bb/cascades/CustomControl>
namespace bb {
namespace cascades {
class Container;
}
}
using namespace bb::cascades;
class QNetworkAccessManager;
class PostHttp: public QObject {
Q_OBJECT
public:
PostHttp(QObject* parent = 0);
bb::cascades::Image m_image;
ImageView* imageView;
Container* mRootContainer;
bool createFolder(QString path);
bool openAndSaveFile(QString filePathWithName, QNetworkReply* reply);
public Q_SLOTS:
void loginWebService(const QString &body, const QString &pass,
bool istoken);
void newsFeedWebService(const qint16 num);
void logoutWebService();
void imageFetcher();
void get(const QUrl &url);
void post(const QVariantMap &body, const QUrl &url);
Q_SIGNALS:
void complete(const QVariantList &info);
void newsfeedComplete(const QVariantList &info);
void imageLoaded(const QVariant &image);
private Q_SLOTS:
void onGetReply();
void onNewsFeedReply();
void onImageReply();
Q_INVOKABLE void generatePage();
Q_INVOKABLE void loadImages();
private:
bb::cascades::QListDataModel<QObject*>* m_model;
QImage setImage(const QImage &image);
bb::cascades::DataModel* model() const;
QNetworkAccessManager* m_networkAccessManager;
bb::data::JsonDataAccess* dataAccess;
public:
QString token;
};
#endif
PostHttp.cpp
#include "PostHttp.hpp"
#include <QDebug>
#include <QNetworkAccessManager>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QSslConfiguration>
#include <QUrl>
#include <bb/data/JsonDataAccess>
#include <QDateTime>
#include <bb/cascades/AbstractPane>
#include <bb/cascades/Application>
#include <bb/cascades/QmlDocument>
#include <bb/cascades/Page>
#include <bb/cascades/StandardListItem>
#include <QFile>
#include <bb/ImageData>
#include <QNetworkReply>
#include <QNetworkDiskCache>
#include <QDesktopServices>
#include <bb/cascades/Image>
#include <bb/cascades/Container>
#include <bb/cascades/ImageView>
#include <bb/cascades/ScalingMethod>
#include <bb/cascades/DockLayout>
#include <bb/cascades/controls/activityindicator.h>
#include <bb/cascades/controls/scrollview.h>
#include <bb/cascades/controls/page.h>
#include <bb/cascades/NavigationPaneProperties>
#include <bb/cascades/Color>
using namespace bb::data;
using namespace bb::cascades;
using namespace bb::utility;
QString globalTokenValue;
int globalUserId;
bool flag = true;
bool flag1 = true;
QVariantList data;
PostHttp::PostHttp(QObject* parent) :
QObject(parent), m_networkAccessManager(
new QNetworkAccessManager(this)), m_model(
new QListDataModel<QObject*>()) {
}
//! [0]
/**
* PostHttp::post
*
* Make a network request to httpbin.org/post with POST data and get
* the response
*/
//! [1]
void PostHttp::post(const QVariantMap &body, const QUrl &url) {
JsonDataAccess jda;
QByteArray jsonData;
jda.saveToBuffer(*(&body), &jsonData);
QByteArray postDataSize = QByteArray::number(jsonData.size());
QNetworkRequest request(*(&url));
request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");
request.setHeader(QNetworkRequest::ContentLengthHeader,
QString(postDataSize).toUtf8());
//QNetworkReply* reply = m_networkAccessManager->post(request, body.toAscii());
qDebug() << "json" << jsonData;
QNetworkReply* reply = m_networkAccessManager->post(request, jsonData);
qDebug() << "strdgfyusujnm kjh " << (&url)->toString();
if ((&url)->toString()
== "http:///GetNewsFeed") {
connect(reply, SIGNAL(finished()), this, SLOT(onNewsFeedReply()));
} else {
connect(reply, SIGNAL(finished()), this, SLOT(onGetReply()));
}
}
void PostHttp::loginWebService(const QString &body, const QString &pass,
bool istoken) {
qint64 date = QDateTime::currentMSecsSinceEpoch();
QString time = QString::number(date);
QVariantMap data;
QVariantMap loginData;
QVariantMap devicedata;
devicedata.insert("OS", "BlackBerry OS 6.0.0.706");
devicedata.insert("deviceId", "232BC441");
devicedata.insert("deviceModel", "9800");
devicedata.insert("screenSize", "480x360");
loginData.insert("device", devicedata);
loginData.insert("email", *(&body));
loginData.insert("password", *(&pass));
loginData.insert("requestDate", "/Date(" + time + "+200)/");
data.insert("apiKey", "4f74721be9b51f24f065b044");
data.insert("data", loginData);
data.insert("requestDate", "/Date(" + time + "+200)/");
if (istoken) {
} else {
data.insert("token", "");
}
const QUrl url(
"http:///LoginRequest");
post(data, url);
}
void PostHttp::newsFeedWebService(const qint16 num) {
qint64 date = QDateTime::currentMSecsSinceEpoch();
QString time = QString::number(date);
QVariantMap data;
QVariantMap newsfeedData;
newsfeedData.insert("postId", 0);
newsfeedData.insert("requestType", 2);
newsfeedData.insert("requestedCount", num);
newsfeedData.insert("userId", globalUserId);
data.insert("apiKey", "4f74721be9b51f24f065b044");
data.insert("data", newsfeedData);
data.insert("requestDate", "/Date(" + time + "+200)/");
data.insert("token", globalTokenValue);
const QUrl url(
"http:///GetNewsFeed");
if (flag == true) {
post(data, url);
}
}
void PostHttp::logoutWebService() {
qint64 date = QDateTime::currentMSecsSinceEpoch();
QString time = QString::number(date);
QVariantMap data;
QVariantMap logoutData;
logoutData.insert("logoutRequestType", 1);
logoutData.insert("userId", globalUserId);
data.insert("apiKey", "4f74721be9b51f24f065b044");
data.insert("data", logoutData);
data.insert("requestDate", "/Date(" + time + "+200)/");
data.insert("token", globalTokenValue);
const QUrl url(
"http:///LogoutUser");
post(data, url);
}
void PostHttp::imageFetcher() {
const QUrl url(
"http://upload.wikimedia.org/wikipedia/commons/e/e7/Nuvola_filesystems_services.png");
if (flag1 == true) {
get(url);
}
}
void PostHttp::get(const QUrl &url) {
QNetworkRequest request(*(&url));
QNetworkReply* reply = m_networkAccessManager->get(request);
connect(reply, SIGNAL(finished()), this, SLOT(onImageReply()));
}
/**
* PostHttp::onGetReply()
*
* SLOT
* Read and return the http response from our http post request
*/
void PostHttp::onGetReply() {
QNetworkReply* reply = qobject_cast<QNetworkReply*>(sender());
QString response;
if (reply) {
if (reply->error() == QNetworkReply::NoError) {
const int available = reply->bytesAvailable();
if (available > 0) {
const QByteArray buffer(reply->readAll());
response = QString::fromUtf8(buffer);
JsonDataAccess dataAccess;
QVariantMap results =
dataAccess.loadFromBuffer(response).toMap();
QString token = (results["Token"]).value<QString>();
int userId = (results["userId"]).value<int>();
if (globalTokenValue == "") {
globalTokenValue = token;
globalUserId = userId;
} else
flag = false;
QString success = (results["Success"]).value<QString>();
}
} else {
response =
tr("Error: %1 status: %2").arg(reply- >errorString(),
reply->attribute(
QNetworkRequest::HttpStatusCodeAttribute).toString());
qDebug() << response;
}
reply->deleteLater();
}
if (response.trimmed().isEmpty()) {
response = tr("Unable to retrieve post response");
}
qDebug() << "response" << response;
}
void PostHttp::onNewsFeedReply() {
QNetworkReply* reply = qobject_cast<QNetworkReply*>(sender());
QString response;
if (reply) {
if (reply->error() == QNetworkReply::NoError) {
flag = false;
const int available = reply->bytesAvailable();
if (available > 0) {
const QByteArray buffer(reply->readAll());
response = QString::fromUtf8(buffer);
JsonDataAccess dataAccess;
QVariantMap results =
dataAccess.loadFromBuffer(response).toMap();
data = results.value("Data").toList();
qDebug() << "first element is" << data.first().toString();
emit newsfeedComplete(data);
}
}
}
}
void PostHttp::onImageReply() {
QNetworkReply* reply = qobject_cast<QNetworkReply*>(sender());
QString response;
QImage img;
QString filePathWithName = "data/img/";
QString imageName;
if (reply) {
if (reply->error() == QNetworkReply::NoError) {
flag1 = false;
const int available = reply->bytesAvailable();
if (available > 0) {
const QByteArray buffer(reply->readAll());
response = QString::fromUtf8(buffer);
img.loadFromData(buffer);
img = img.scaled(40, 40, Qt::KeepAspectRatioByExpanding);
const QImage swappedImage = img.rgbSwapped();
const bb::ImageData imageData = bb::ImageData::fromPixels(
swappedImage.bits(), bb::PixelFormat::RGBX,
swappedImage.width(), swappedImage.height(),
swappedImage.bytesPerLine());
QByteArray byteArray = bb::utility::ImageConverter::encode(
"image/png", imageData, 75);
qDebug() << "bytearray is" << byteArray;
// QVariant image(byteArray);
QVariant realImage(byteArray);
qDebug() << "imag of image is" << realImage;
emit imageLoaded(realImage);
}
}
}
}
//! [1]
And finally my QML file is
NewsFeed.qml
import bb.cascades 1.0
import Network.PostHttp 1.0
import bb.cascades 1.0
import "controls"
import my.library 1.0
Page {
actions: [
ActionItem {
title: "Logout"
onTriggered: {
netpost.logoutWebService();
Application.quit();
}
ActionBar.placement: ActionBarPlacement.OnBar
}
]
id:mainpage
onCreationCompleted: {
Qt.mainImageview = imageviewid;
}
Container {
layout: DockLayout {
}
// The background image
ImageView {
horizontalAlignment: HorizontalAlignment.Fill
verticalAlignment: VerticalAlignment.Fill
imageSource: "asset:///images/background.png"
}
//! [0]
Container {
id : innercontainer
ActivityIndicator {
id: progressIndicator
horizontalAlignment: HorizontalAlignment.Fill
verticalAlignment: VerticalAlignment.Fill
onStarted: {
}
onCreationCompleted: {
progressIndicator.running = true;
}
}
ListView {
id: listView
objectName: "listView"
dataModel: ArrayDataModel {
id: myListModel
}
// Override default GroupDataModel::itemType() behaviour, which is to return item type "header"
listItemComponents: ListItemComponent {
id: listcomponent
// StandardListItem is a convivience component for lists with default cascades look and feel
StandardListItem {
title: ListItemData.postText
description: ListItemData.postDate
status: ListItemData.filePath
imageSource: "asset:///images/4.png"
}
}
layoutProperties: StackLayoutProperties {
spaceQuota: 1.0
}
horizontalAlignment: HorizontalAlignment.Fill
verticalAlignment: VerticalAlignment.Fill
}
Container {
id: root
layout: StackLayout {
}
Label {
text: ListItemData.postText
horizontalAlignment: HorizontalAlignment.Left
verticalAlignment: VerticalAlignment.Bottom
}
Label {
text: ListItemData.postDate
// textStyle.fontSize: 5
horizontalAlignment: HorizontalAlignment.Right
verticalAlignment: VerticalAlignment.Bottom
}
attachedObjects: [
QTimer {
id: timer
property int f: 0
interval: 5000
onTimeout: {
progressIndicator.running = false;
netpost.imageFetcher();
netpost.newsFeedWebService("10");
}
},
PostHttp {
id: netpost
onComplete: {
progressIndicator.running = false;
progressIndicator.visible = false;
console.log("dsfdsafs"+netpost.model)
timer.stop();
}
onImageLoaded:{
console.log("value is image from cpp jhgsdh " + image)
imageviewid.setImageSource(image)
}
onNewsfeedComplete: {
console.log("response from newsfeed is "+info)
myListModel.append(info)
}
}
]
}
onCreationCompleted: {
// this slot is called when declarative scene is created
// write post creation initialization here
console.log("Page - onCreationCompleted()")
// enable layout to adapt to the device rotation
// don't forget to enable screen rotation in bar-bescriptor.xml (Application->Orientation->Auto-orient)
OrientationSupport.supportedDisplayOrientation = SupportedDisplayOrientation.All;
// populate list view model with the sample data
timer.start();
// myListModel.load("app/native/assets/mydata.json")
}
ImageView {
id: imageviewid
imageSource: "asset:///images/4.png"
enabled: true
loadEffect: ImageViewLoadEffect.FadeZoom
}
}
}
}
Please help me with this.
回答1:
So you've defined your slot with QVariant parameter however trying to emit it with QByteArray type which is returned by ImageConverter::encode() call.
Try to change that part of your code to this and give it a go:
QByteArray byteArray = bb::utility::ImageConverter::encode(QUrl(QDir::currentPath() + "/shared/camera/img.png"), imageData, 75);
QVariant image(byteArray);
emit imageLoaded(image);
Also, double check that everywhere where you declare/define this pair of signal/slot you're specified exactly the same parameter notation (ie const QVariant& in case of imageLoaded() signal and so on)
回答2:
Try this sample code and implement by re-altering in your project
1.QML FILE
import bb.cascades 1.0
Page {
content: Container {
ListView {
dataModel: _app.model
function itemType (data, indexPath) {
return data["type"];
}
listItemComponents: [
]
}
}
}
2.HPP FILE
#ifndef APP_HPP
#define APP_HPP
#include <QtCore/QObject>
#include <QtNetwork/QNetworkAccessManager>
#include <bb/cascades/QListDataModel>
class App: public QObject
{
Q_OBJECT
Q_PROPERTY(bb::cascades::DataModel *model READ model NOTIFY modelChanged)
public:
App();
bb::cascades::DataModel * model() const;
Q_SIGNALS:
void modelChanged();
private Q_SLOTS:
void handleNetworkData(QNetworkReply *reply);
private:
mutable bb::cascades::QMapListDataModel *dataModel;
QNetworkAccessManager networkManager;
};
#endif // APP_HPP
3.CPP FILE
#include <bb/cascades/Page>
#include <bb/cascades/QmlDocument>
#include <bb/data/JsonDataAccess>
#include "App.hpp"
using namespace bb::cascades;
using namespace bb::data;
App::App() :
{
// Load up the QML for our view
QmlDocument *qml = QmlDocument::create("view.qml");
// Provide a reference to this class
qml->setContextProperty("_app", this);
// Create the root node of this view
Page *view = qml->createRootNode<Page>();
dataModel = new QMapListDataModel();
// Hook this signal so we can respond to network replies
connect(&networkManager, SIGNAL(finished(QNetworkReply *)), this,
SLOT(handleNetworkData(QNetworkReply *)));
// Do the request
QUrl url = "http://jsonservice.com/news/headlines/";
networkManager.get(QNetworkRequest(url));
}
DataModel * App::model() const
{
return dataModel;
}
void App::handleNetworkData(QNetworkReply *reply)
{
if (!reply->error()) {
const QByteArray response(reply->readAll());
JsonDataAccess jda;
QVariantMap results = jda.loadFromBuffer(response).toMap();
// Get the relevant parts we want from the JSON
QVariantList posts = results["data"].toMap()["children"].toList();
Q_FOREACH(QVariant post, posts) {
dataModel->append(post);
}
}
// Cleanup
reply->deleteLater();
}
来源：https://stackoverflow.com/questions/17715533/dynamically-set-imagesource-in-imageview-blackberry-10