使用qml开发应用程序，qml设计界面更加的快捷美观，逻辑程序的实现使用 C++。
使用qml 怎样设计出合适的界面，胸有成竹是关键，你心里想的明确的，界面的实现便是调代码了，怎样实现心中的样子，设计样式根据什么来设计，查看Qt的源代码，会有很多收获，刚开始接触qml开发有一头雾水，慢慢做着，发现挺简单的，其实只是假象，很多知识点并没有深入了解，QML与C++的交互，在开发中十分重要，开始做起来也感觉很棘手。
在Qt安装目录下C:\Qt\Qt5.7.0\5.7\mingw53_32\qml\QtQuick\Controls\Styles\Base可以找到QML相关控件的样式 qml
下面以比较常用的控件为例，将例子代码拷贝处理，结合Qt助手根据需求修改一下，
/****************************************************************************
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import QtQuick 2.2
import QtQuick.Controls 1.2
import QtQuick.Controls.Private 1.0
/*!
\qmltype ButtonStyle
\inqmlmodule QtQuick.Controls.Styles
\since 5.1
\ingroup controlsstyling
\brief Provides custom styling for Button
You can create a custom button by replacing the "background" delegate
of the ButtonStyle with a custom design.
Example:
\qml
Button {
text: "A button"
style: ButtonStyle {
background: Rectangle {
implicitWidth: 100
implicitHeight: 25
border.width: control.activeFocus ? 2 : 1
border.color: "#888"
radius: 4
gradient: Gradient {
GradientStop { position: 0 ; color: control.pressed ? "#ccc" : "#eee" }
GradientStop { position: 1 ; color: control.pressed ? "#aaa" : "#ccc" }
}
}
}
}
\endqml
If you need a custom label, you can replace the label item.
*/
Style {
id: buttonstyle
/*! The \l {QtQuick.Controls::}{Button} this style is attached to. */
readonly property Button control: __control
/*! The padding between the background and the label components. */
padding {
top: 4
left: 4
right: 4 + (control.menu !== null ? Math.round(TextSingleton.implicitHeight * 0.5) : 0)
bottom: 4
}
/*! This defines the background of the button. */
property Component background: Item {
property bool down: control.pressed || (control.checkable && control.checked)
implicitWidth: Math.round(TextSingleton.implicitHeight * 4.5)
implicitHeight: Math.max(25, Math.round(TextSingleton.implicitHeight * 1.2))
Rectangle {
anchors.fill: parent
anchors.bottomMargin: down ? 0 : -1
color: "#10000000"
radius: baserect.radius
}
Rectangle {
id: baserect
gradient: Gradient {
GradientStop {color: down ? "#aaa" : "#fefefe" ; position: 0}
GradientStop {color: down ? "#ccc" : "#e3e3e3" ; position: down ? 0.1: 1}
}
radius: TextSingleton.implicitHeight * 0.16
anchors.fill: parent
border.color: control.activeFocus ? "#47b" : "#999"
Rectangle {
anchors.fill: parent
radius: parent.radius
color: control.activeFocus ? "#47b" : "white"
opacity: control.hovered || control.activeFocus ? 0.1 : 0
Behavior on opacity {NumberAnimation{ duration: 100 }}
}
}
Image {
id: imageItem
visible: control.menu !== null
source: "images/arrow-down.png"
anchors.verticalCenter: parent.verticalCenter
anchors.right: parent.right
anchors.rightMargin: 4
opacity: control.enabled ? 0.6 : 0.5
}
}
/*! This defines the label of the button. */
property Component label: Item {
implicitWidth: row.implicitWidth
implicitHeight: row.implicitHeight
baselineOffset: row.y + text.y + text.baselineOffset
Row {
id: row
anchors.centerIn: parent
spacing: 2
Image {
source: control.iconSource
anchors.verticalCenter: parent.verticalCenter
}
Text {
id: text
renderType: Settings.isMobile ? Text.QtRendering : Text.NativeRendering
anchors.verticalCenter: parent.verticalCenter
text: StyleHelpers.stylizeMnemonics(control.text)
color: SystemPaletteSingleton.buttonText(control.enabled)
}
}
}
/*! \internal */
property Component panel: Item {
anchors.fill: parent
implicitWidth: Math.max(labelLoader.implicitWidth + padding.left + padding.right, backgroundLoader.implicitWidth)
implicitHeight: Math.max(labelLoader.implicitHeight + padding.top + padding.bottom, backgroundLoader.implicitHeight)
baselineOffset: labelLoader.item ? padding.top + labelLoader.item.baselineOffset : 0
Loader {
id: backgroundLoader
anchors.fill: parent
sourceComponent: background
}
Loader {
id: labelLoader
sourceComponent: label
anchors.fill: parent
anchors.leftMargin: padding.left
anchors.topMargin: padding.top
anchors.rightMargin: padding.right
anchors.bottomMargin: padding.bottom
}
}
}
/*********************************************************************************************************/
查看QML助手，找到关于Button在qml中使用，Qt提供的资源很丰富，与其上网搜索，不如仔细阅读官方的说明文档，方便快捷。
QML中Button控件的样式和相关属性方法在Qt助手中截图
//自己的例子
import QtQuick 2.3
import QtQuick.Controls 1.2
import QtQuick.Controls.Styles 1.2
import "."
ButtonStyle {
id: textfieldstyle
property font font
background: Rectangle {
id: bg
color: !control.pressed ? " white" : "palegreen"
radius: 8
border.color: "black"
border.width: 2
}
label: Text {
id: textLabel
renderType: Text.NativeRendering
verticalAlignment: Text.AlignVCenter
horizontalAlignment: Text.AlignHCenter
color: control.pressed ? "white" : "darkslategray"
text: control.text
font: textfieldstyle.font
}
padding.left: 20
padding.right: 20
padding.top: 20
padding.bottom: 20
}