QtQuick 技巧6

QtQuick 技巧6

开启图像调试模式

参见 Qt Quick Scene Graph Renderer

通过给环境变量 QSG_VISUALIZE 设置 batches，clip，changes，overdraw 即可进行图像调试.

如何给项目设置环境变量？

打开 QtCreator 最左侧的 项目 界面，构建工具切换到运行，找一找 Run Environment 或者 运行环境，直接添加 QSG_VISUALIZE 环境变量，并设置相应的值即可。此外设置的环境变量不会保存到系统环境变量，可以放行大胆的尝试。

开启 import 调试

设置 QML_IMPORT_TRACE=1 环境变量，即可查看 qml import 了那些库。

 QQmlImportDatabase::addImportPath "/qt-sdk/imports"
 QQmlImportDatabase::addImportPath "/qt-sdk/bin/QMLViewer.app/Contents/MacOS"
 QQmlImportDatabase::addToImport 0x106237370 "." -1.-1 File as ""
 QQmlImportDatabase::addToImport 0x106237370 "Qt" 4.7 Library as ""
 QQmlImportDatabase::resolveType "Rectangle" = "QDeclarativeRectangle"

Debugging QML Applications

一些 QML 代码

version >= Qt. 5.5

竖向布局，可滚动。

Item {id: rootanchors.fill: parentanchors.margins: 10Flickable {anchors.fill: parentflickableDirection: ListView.VerticalFlickcontentWidth: columnLayout.implicitWidthcontentHeight: columnLayout.implicitHeightColumnLayout {id: columnLayoutwidth: root.width}}
}

QML 中可使用的加密，Hash 库

brix/crypto-js

JavaScript library of crypto standards.

配置：

// crypto-js.js
Qt.include("./src/core.js");
Qt.include("./src/lib-typedarrays.js");
Qt.include("./src/x64-core.js");
Qt.include("./src/enc-utf16.js");
Qt.include("./src/enc-base64.js");
Qt.include("./src/md5.js");
Qt.include("./src/sha1.js");
Qt.include("./src/sha256.js");
Qt.include("./src/sha224.js");
Qt.include("./src/sha512.js");
Qt.include("./src/sha384.js");
Qt.include("./src/sha3.js");
Qt.include("./src/ripemd160.js");
Qt.include("./src/hmac.js");
Qt.include("./src/pbkdf2.js");
Qt.include("./src/evpkdf.js");
Qt.include("./src/cipher-core.js");
Qt.include("./src/mode-cfb.js");
Qt.include("./src/mode-ctr.js");
Qt.include("./src/mode-ofb.js");
Qt.include("./src/mode-ecb.js");
Qt.include("./src/pad-ansix923.js");
Qt.include("./src/pad-iso10126.js");
Qt.include("./src/pad-zeropadding.js");
Qt.include("./src/pad-iso97971.js");
Qt.include("./src/pad-nopadding.js");
Qt.include("./src/rc4.js");
Qt.include("./src/rabbit.js");
Qt.include("./src/rabbit-legacy.js");
Qt.include("./src/aes.js");
Qt.include("./src/tripledes.js");

使用：

import QtQuick 2.0import "./crypto-js/crypto-js.js" as CryptoJSLibItem {width: 360height: 640function testSHA256() {
    var encrypted = CryptoJSLib.CryptoJS.SHA256("");console.log("SHA256:", encrypted);}MouseArea {anchors.fill: parentonClicked: {testSHA256();}}
}

参考项目 qml-snippet/code/crypto-qml