WPF Binding Value Converter Valueconverter Introduction to use (ii)-imultivalueconverter

Note:

The Imultivalueconverter interface needs to be inherited, and the interface uses the same logic as IValueConverter.

One, Multibinding+converter multi-value binding and multi-value conversion example

The LED should be green when the longitudinal flow is greater than the horizontal flow, and the LED should be red when the longitudinal flow is less than the horizontal flow, otherwise the LED is yellow.

1, custom Colorconverter class, at this time convert in the parameter is object[] values,values[0] corresponding to the first binding value in MultiBinding, here is the vertical flow value, and so on , you can Multiple bindings are specified in the MultiBinding object.

 Public classcolorconverter:imultivalueconverter{//Forward Modification     Public ObjectConvert (Object[] values, Type targetType,Objectparameter, CultureInfo culture) {        if(Values = =NULL|| Values. Length <2)            returnDependencyproperty.unsetvalue; DoubleVervalue = (Double) values[0]; DoubleHorvalue = (Double) values[1]; if(Vervalue >horvalue)return NewSolidColorBrush (Colors.green); Else if(Vervalue <horvalue)return NewSolidColorBrush (colors.red); return NewSolidColorBrush (Colors.yellow); }    //Reverse Modification     Public Object[] Convertback (ObjectValue, type[] targettypes,Objectparameter, CultureInfo culture) {        //return NULL, token non-bidirectional conversion        return NULL; }}

2.Xaml definition

Add a Namespace

Xmlns:local= "Clr-namespace:audiodemo.view"

<window.resources>    <Local:colorconverterx:key= "Cvtcolor"/></window.resources><Grid>    <Labelx:name= "Label"Content= "Portrait Value:"HorizontalAlignment= "Left"Margin= "10,40,0,0"VerticalAlignment= "Top"/>    <Labelx:name= "Label1"Content= "Transverse value:"HorizontalAlignment= "Left"Margin= "10,80,0,0"VerticalAlignment= "Top"/>    <Sliderx:name= "Sliderver"HorizontalAlignment= "Left"Margin= "75,43,0,0"VerticalAlignment= "Top"Width= "192"/>    <Sliderx:name= "Sliderhor"HorizontalAlignment= "Left"Margin= "75,81,0,0"VerticalAlignment= "Top"Width= "192"/>    <EllipseHorizontalAlignment= "Left"Height= "+"Margin= "75,120,0,0"Stroke= "Black"VerticalAlignment= "Top"Width= "+">        <Ellipse.fill>            <multibindingConverter="{StaticResource Cvtcolor}">                <BindingPath= "Value"elementname= "Sliderver"/>                <BindingPath= "Value"elementname= "Sliderhor"/>            </multibinding>        </Ellipse.fill>    </Ellipse></Grid>

Two, RGB color mixed instance

1. Converter definition

 Public classrgbconverter:imultivalueconverter{//forward modification, integrating color values     Public ObjectConvert (Object[] values, Type targetType,Objectparameter, CultureInfo culture) {        if(Values = =NULL|| Values. Length <3)            return NULL; byteR = System.Convert.ToByte (values[0]); byteg = System.Convert.ToByte (values[1]); byteb = System.Convert.ToByte (values[2]); Color Col=Color.fromrgb (R, G, b); SolidColorBrush Brush=NewSolidColorBrush (COL); returnBrush; }     Public Object[] Convertback (ObjectValue, type[] targettypes,Objectparameter, CultureInfo culture) {        return NULL; }}

2.Xaml definition

Don't forget to add namespaces first

Xmlns:local= "Clr-namespace:audiodemo.view"

<window.resources>    <Local:rgbconverterx:key= "RGBCVT"/></window.resources><Grid>    <Labelx:name= "Label"Content= "Red:"HorizontalAlignment= "Left"Margin= "10,48,0,0"VerticalAlignment= "Top"/>    <Labelx:name= "Label_copy"Content= "Green:"HorizontalAlignment= "Left"Margin= "7,85,0,0"VerticalAlignment= "Top"/>    <Labelx:name= "Label_copy1"Content= "Blue:"HorizontalAlignment= "Left"Margin= "7,123,0,0"VerticalAlignment= "Top"/>    <Sliderx:name= "Slider_r"Minimum= "0"Maximum= "255"Ticks= "1"HorizontalAlignment= "Left"Margin= "68,53,0,0"VerticalAlignment= "Top"Width= "207"/>    <Sliderx:name= "Slider_g"Minimum= "0"Maximum= "255"Ticks= "1"HorizontalAlignment= "Left"Margin= "68,91,0,0"VerticalAlignment= "Top"Width= "207"/>    <Sliderx:name= "Slider_b"Minimum= "0"Maximum= "255"Ticks= "1"HorizontalAlignment= "Left"Margin= "68,124,0,0"VerticalAlignment= "Top"Width= "207"/>    <RectangleHorizontalAlignment= "Left"Height= "All"Margin= "68,160,0,0"Stroke= "Black"VerticalAlignment= "Top"Width= "142">        <Rectangle.fill>            <multibindingConverter="{StaticResource RGBCVT}">                <Bindingelementname= "Slider_r"Path= "Value"></Binding>                <Bindingelementname= "Slider_g"Path= "Value"></Binding>                <Bindingelementname= "Slider_b"Path= "Value"></Binding>            </multibinding>        </Rectangle.fill>    </Rectangle></Grid>

Operation Result:

More information: WPF binding value Converter valueconverter usage profile (i)

WPF Binding Value Converter Valueconverter Introduction to use (ii)-imultivalueconverter