使用go-qml从QML获取用户输入

huangapple
go评论126阅读模式
英文:

Get user input from QML using go-qml

问题

我正在尝试从qml中获取用户输入，使用gopkg.in/qml.v1包。
成功设置了来自Go的值。但是我无法获取更改后的值。
例如，我从Go代码中将_Name_设置到qml中。用户更改文本字段并按下_Button_后，我读取用户输入并返回"Hello, " + ctrl.Name

这是一个示例：

main.go

  1. package main
  3. import (
  4.     "fmt"
  5.     "gopkg.in/qml.v1"
  6.     "os"
  7. )
  9. func main() {
  10.     if err := qml.Run(run); err != nil {
  11.         fmt.Fprintf(os.Stderr, "error: %v\n", err)
  12.         os.Exit(1)
  13.     }
  14. }
  16. func run() error {
  17.     engine := qml.NewEngine()
  19.     component, err := engine.LoadFile("main.qml")
  20.     if err != nil {
  21.         return err
  22.     }
  24.     context := engine.Context()
  25.     context.SetVar("ctrl", &Control{Name: "Enter your name"})
  27.     window := component.CreateWindow(nil)
  29.     window.Show()
  30.     window.Wait()
  32.     return nil
  33. }
  35. type Control struct {
  36.     Name    string
  37.     Message string
  38. }
  40. func (ctrl *Control) Hello() {
  41.     go func() {
  42.         ctrl.Message = "Hello, " + ctrl.Name
  43.         qml.Changed(ctrl, &ctrl.Message)
  44.     }()
  45. }

main.qml

  1. import QtQuick 2.0
  2. import QtQuick.Controls 1.1
  4. Rectangle {
  5.     id: root
  6.     color: "#ffffff"
  8.     width: 320
  9.     height: 320
  11.     TextEdit {
  12.         id: textEdit1
  13.         x: 8
  14.         y: 8
  15.         width: 304
  16.         height: 20
  17.         text: ctrl.name
  18.         font.pixelSize: 12
  19.     }
  21.     Button {
  22.         id: button1
  23.         x: 8
  24.         y: 34
  25.         width: 304
  26.         height: 27
  27.         text: qsTr("Button")
  28.         onClicked: {
  29.             ctrl.hello()
  30.         }
  31.     }
  33.     Text {
  34.         id: text1
  35.         x: 8
  36.         y: 67
  37.         width: 304
  38.         height: 23
  39.         text: ctrl.message
  40.         font.pixelSize: 12
  41.     }
  42. }

为了使其工作，我必须在_Button_的onClicked()中添加显式赋值，像这样：

  1. Button {
  2.     id: button1
  3.     x: 8
  4.     y: 34
  5.     width: 304
  6.     height: 27
  7.     text: qsTr("Button")
  8.     onClicked: {
  9.         ctrl.name = textEdit1.text
  10.         ctrl.hello()
  11.     }
  12. }

我做错了什么？谢谢。

英文:

I attempting to get user input from qml, using gopkg.in/qml.v1 package.
Setting up values from Go is successful. But I can't get back changed values.
For example, I set Name from go code to qml. After user change text field and push Button, I read user input and push back "Hello, " + ctrl.Name

This is example:

main.go

  1. package main
  3. import (
  4.     "fmt"
  5.     "gopkg.in/qml.v1"
  6.     "os"
  7. )
  9. func main() {
  10.     if err := qml.Run(run); err != nil {
  11.         fmt.Fprintf(os.Stderr, "error: %v\n", err)
  12.         os.Exit(1)
  13.     }
  14. }
  16. func run() error {
  17.     engine := qml.NewEngine()
  19.     component, err := engine.LoadFile("main.qml")
  20.     if err != nil {
  21.         return err
  22.     }
  24.     context := engine.Context()
  25.     context.SetVar("ctrl", &Control{Name: "Enter your name"})
  27.     window := component.CreateWindow(nil)
  29.     window.Show()
  30.     window.Wait()
  32.     return nil
  33. }
  35. type Control struct {
  36.     Name    string
  37.     Message string
  38. }
  40. func (ctrl *Control) Hello() {
  41.     go func() {
  42.         ctrl.Message = "Hello, " + ctrl.Name
  43.         qml.Changed(ctrl, &ctrl.Message)
  44.     }()
  45. }

main.qml

  1. import QtQuick 2.0
  2. import QtQuick.Controls 1.1
  4. Rectangle {
  5.     id: root
  6.     color: "#ffffff"
  8.     width: 320
  9.     height: 320
  11.     TextEdit {
  12.         id: textEdit1
  13.         x: 8
  14.         y: 8
  15.         width: 304
  16.         height: 20
  17.         text: ctrl.name
  18.         font.pixelSize: 12
  19.     }
  21.     Button {
  22.         id: button1
  23.         x: 8
  24.         y: 34
  25.         width: 304
  26.         height: 27
  27.         text: qsTr("Button")
  28.         onClicked: {
  29.             ctrl.hello()
  30.         }
  31.     }
  33.     Text {
  34.         id: text1
  35.         x: 8
  36.         y: 67
  37.         width: 304
  38.         height: 23
  39.         text: ctrl.message
  40.         font.pixelSize: 12
  41.     }
  42. }

To make this work, I have to add explicit assignment in Button onClicked() like this:

  1. Button {
  2.     id: button1
  3.     x: 8
  4.     y: 34
  5.     width: 304
  6.     height: 27
  7.     text: qsTr("Button")
  8.     onClicked: {
  9.         ctrl.name = textEdit1.text
  10.         ctrl.hello()
  11.     }
  12. }

What I do wrong? Thank you

答案1

得分: 4

你必须使用绑定来更新ctrl.name，否则它将保持不变：

  1. TextEdit {
  2.     id: textEdit1
  3.     x: 8
  4.     y: 8
  5.     width: 304
  6.     height: 20
  7.     text: ctrl.name
  8.     font.pixelSize: 12
  9. }
  10. Binding { target: ctrl; property: "name"; value: textEdit1.text }

参考：http://qt-project.org/doc/qt-5/qml-qtqml-binding.html

英文:

You have to use a binding to update ctrl.name otherwise it stays the same:

  1. TextEdit {
  2. 	id: textEdit1
  3. 	x: 8
  4. 	y: 8
  5. 	width: 304
  6. 	height: 20
  7. 	text: ctrl.name
  8. 	font.pixelSize: 12
  9. }
  10. Binding { target: ctrl; property: "name"; value: textEdit1.text }

ref: http://qt-project.org/doc/qt-5/qml-qtqml-binding.html

huangapple
  • 本文由 发表于 2014年9月7日 15:10:36
  • 转载请务必保留本文链接：https://go.coder-hub.com/25707951.html
  • go
  • qml
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