qml主窗口背景梯度

Question

我有这样的想法。我想有一个梯度，而不是单色背景在myApp主窗口。

我测试了不同的代码方式，但没有成功。

结果总是一样的。要么背景为纯白色，要么显示黑白渐变(见图)。

你能告诉我怎么做才对吗？我需要更深的东西。此外，也许在其他颜色。但这只显示了一切都是黑白的。

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import QtQuick 2.9
import QtQuick.Controls 2.2
import QtGraphicalEffects 1.0

ApplicationWindow {
id: window
visible: true
width: 425
height: 850
title: qsTr("myApp")

/*
Item
{
    Gradient
    {
        GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
        GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
        GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
        GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
        GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
        GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
        GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
    }
}

//totaly not works
Rectangle
{
    Gradient
    {
        GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
        GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
        GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
        GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
        GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
        GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
        GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
    }
}


//totaly not works
Gradient
{
    GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
    GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
    GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
    GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
    GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
    GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
    GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
}


//malfunction - still show only two colors - black nad white
RadialGradient
{
    anchors.fill: parent
    GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
    GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
    GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
    GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
    GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
    GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
    GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
}


//malfunction - still show only two colors - black nad white
Rectangle
{
    anchors.fill: parent
    Gradient
    {
        GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
        GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
        GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
        GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
        GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
        GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
        GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
    }
}


//Totaly not works
Item
{
    Gradient
    {
        GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
        GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
        GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
        GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
        GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
        GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
        GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
    }
}

*/


Item
{
    anchors.fill: parent
    RadialGradient
    {
        anchors.fill: parent
        GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
        GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
        GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
        GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
        GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
        GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
        GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
    }
}

}

Answer 1

必须将渐变停止列表应用于可视项的gradient属性。

若要在Item中使用矩形，必须指定项的尺寸，默认项的高度和宽度为零。

import QtQuick 2.9
import QtQuick.Controls 2.2
import QtGraphicalEffects 1.0

ApplicationWindow {
id: window
visible: true
width: 425
height: 850
title: qsTr("myApp")


Rectangle
{
    anchors.fill: parent
    gradient: Gradient
    {
        GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
        GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
        GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
        GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
        GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
        GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
        GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
    }
}
}

​

​

使用径向梯度

import QtQuick 2.9
import QtQuick.Controls 2.2
import QtGraphicalEffects 1.0

ApplicationWindow {
id: window
visible: true
width: 425
height: 850
title: qsTr("myApp")

Item
{
    anchors.fill: parent
     RadialGradient
    {
        anchors.fill: parent
        gradient: Gradient{
        GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
        GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
        GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
        GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
        GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
        GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
        GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
        }
    }
}
}

​

​