Polyline使用DataBinding和PointCollection进行连续更新 [英] Polyline using DataBinding and PointCollection for continuous update
问题描述
首先我描述我的目标，我想要achive。我想要可视化一个连续的数据流（每秒最多1000个值，但可以减少）。这个数据流应该可视化为图表 - 更精确的是它是ECG的可视化。
我的第一个想法是使用折线并将其绑定到点集合。这里的问题是UI上没有显示任何内容。也许这是一个错误的aproach这个任务。欢迎更好的想法。这里ist我的代码到目前为止。第一个视图：
< Canvas>
< Polyline Points ={Binding Points}Stroke =RedStrokeThickness =2/>
< / Canvas>
为了简单起见，我使用代码隐藏我使用MVVM模式。这也是为什么我想使用绑定，而不只是折线的名称和添加值的原因。
public partial class MainWindow：Window
{
private short [] data = new short [] {10,30， 50,70,90,110,130,150,170,190,210};
private short [] data1 = new short [] {15,14,16,13,17,12,18,11,19,10,24}; public MainWindow（）
{
InitializeComponent（）;
for（int i = 0; i
Points.Add（new Point（data [i]，data1 [i]））
}
}
private PointCollection _points = new PointCollection（）;
public PointCollection Points
{
get {return _points; }
}
}
我知道这是没有好的编码风格，但首先测试它足够为我。我使用数组数据的x值和数据1的y值。任何人都可以告诉我这个绑定有什么问题？每当新值出现时，为视图的连续更新应该做什么？
感谢您的帮助。
[更新的新版本]
视图：
< Window.Resources>
< my：PointCollectionConverter x：Key =myPointsConverter/>
< /Window.Resources>
< Grid Name =grid>
< Polyline x：Name =ekglineIPoints ={Binding Points，Converter = {StaticResource myPointsConverter}}Stroke =RedStrokeThickness =2/>
< Button Content =ButtonClick =button1_Click/>
< / Grid>
代码隐藏在启动时绘制折线，
public partial MainWindow：Window，INotifyPropertyChanged
{
private short [] data = new short [] { 30，50，70，90，110，130，150，170，190，210};
private short [] data2 = new short [] {230,250,270,290,300,310,330,350,370,390,410};
private short [] data1 = new short [] {15，14，16，13，17，12，18，11，19，10，24};
public MainWindow（）
{
InitializeComponent（）;
grid.DataContext = this;
for（int i = 0; i
Points.Add（new Point（data [i]，data1 [i]））
}
}
public event PropertyChangedEventHandler PropertyChanged;
private ObservableCollection _points = new ObservableCollection（）;
public ObservableCollection Points
{
get {return _points; }
}
private void button1_Click（object sender，RoutedEventArgs e）
{
（int i = 0; i
Points.Add（new Point（data2 [i]，data1 [i]））
}
PropertyChanged（this，new PropertyChangedEventArgs（Points））;
}
现在我想做的是摆脱这行： grid.DataContext = this; ，这样我可以使用我的MVVM或有另一种可能性？
Kai要使更改通知传播到您的绑定，你应该使用实现变化通知的集合， PointCollection 不这样做。您可以创建自己的集合，但我建议使用 ObservableCollection< T> 。
是类似的 SO帖子，其中还涉及了一些其他选项，让UI了解您的更改。
first of all I describe my objective I want to achive. I want to visualise a continuous data stream (maximum 1000 values per second but could be reduced). This data stream should be visualised as a chart - being more precise it's a visualisation of an ECG among other things.
My first idea was using polyline and bind it to a point collection. The problem here is that nothing is shown on the UI. Perhaps it's a wrong aproach for this task. Better ideas are welcomed. Here ist my code so far. First the View:
<Canvas>
<Polyline Points="{Binding Points}" Stroke="Red" StrokeThickness="2" />
</Canvas>
For the sake of simplicity I use the code-behind even though I use the MVVM-pattern. That's also the reason why I want to use the binding and not just the name of the polyline and add the values.
public partial class MainWindow : Window
{
private short[] data = new short[]{ 10,30,50,70,90,110,130,150,170,190,210 };
private short[] data1 = new short[] { 15,14,16,13,17,12,18,11,19,10,24 }; public MainWindow()
{
InitializeComponent();
for (int i = 0; i < data.Length; i++)
{
Points.Add(new Point(data[i], data1[i]));
}
}
private PointCollection _points = new PointCollection();
public PointCollection Points
{
get { return _points; }
}
}
I know that is no good coding style but for first tests its enough for me. I use array data for x-values and data1 for y-values. Can anyone tell me whats wrong with that binding? What's to be done for a continuous update of the view, whenever new values occur?
Thanks for your help in advance.
[Updated new version] The view:
<Window.Resources>
<my:PointCollectionConverter x:Key="myPointsConverter"/>
</Window.Resources>
<Grid Name="grid">
<Polyline x:Name="ekglineI" Points="{Binding Points, Converter={StaticResource myPointsConverter}}" Stroke="Red" StrokeThickness="2" />
<Button Content="Button" Click="button1_Click" />
</Grid>
The code-behind which draws a polyline on startup and later on when a button is clicked.
public partial class MainWindow : Window, INotifyPropertyChanged
{
private short[] data = new short[] { 10, 30, 50, 70, 90, 110, 130, 150, 170, 190, 210 };
private short[] data2 = new short[] { 230, 250, 270, 290, 300, 310, 330, 350, 370, 390, 410 };
private short[] data1 = new short[] { 15, 14, 16, 13, 17, 12, 18, 11, 19, 10, 24 };
public MainWindow()
{
InitializeComponent();
grid.DataContext = this;
for (int i = 0; i < data.Length; i++)
{
Points.Add(new Point(data[i], data1[i]));
}
}
public event PropertyChangedEventHandler PropertyChanged;
private ObservableCollection _points = new ObservableCollection();
public ObservableCollection Points
{
get { return _points; }
}
private void button1_Click(object sender, RoutedEventArgs e)
{
for (int i = 0; i < data2.Length; i++)
{
Points.Add(new Point(data2[i], data1[i]));
}
PropertyChanged(this, new PropertyChangedEventArgs("Points"));
}
Now what I want to do is getting rid of this line: grid.DataContext = this; so that I can use my MVVM or is there another possibility?
Kai to make the change notification propagate to your bindings you should be making use of a collection which implements change notificaiton, PointCollection does not do this. You could create your own collection however I'd recommend making use of ObservableCollection<T>.
In addition here is a similar SO post which also touches on a few other options for making the UI aware of your changes.
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