public partial class SLMenus : UserControl
{
public SLMenus()
{
InitializeComponent();
this.SliderAlpha.Value = 225;
this.SliderRed.Value = 225;
this.SliderGreen.Value = 102;
this.SliderBlue.Value = 0;
}
private void Slider_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
{
Color cl = Color.FromArgb((byte)this.SliderAlpha.Value, (byte)this.SliderRed.Value, (byte)SliderBlue.Value, (byte)this.SliderGreen.Value);
PreviewColour.Fill = new SolidColorBrush(cl);
HexColour.Text = cl.ToString();
}
}
网上的例子,怎么还是有“未将对象引用设置到对象的实例”
{
public SLMenus()
{
InitializeComponent();
this.SliderAlpha.Value = 225;
this.SliderRed.Value = 225;
this.SliderGreen.Value = 102;
this.SliderBlue.Value = 0;
}
private void Slider_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
{
Color cl = Color.FromArgb((byte)this.SliderAlpha.Value, (byte)this.SliderRed.Value, (byte)SliderBlue.Value, (byte)this.SliderGreen.Value);
PreviewColour.Fill = new SolidColorBrush(cl);
HexColour.Text = cl.ToString();
}
}
网上的例子,怎么还是有“未将对象引用设置到对象的实例”
this.SliderRed.Value = 225;
this.SliderGreen.Value = 102;
this.SliderBlue.Value = 0;都是null ,不明白为什么是Null
<Grid x:Name="LayoutRoot" Background="White">
<Grid.RowDefinitions>
<RowDefinition Height="120"/>
<RowDefinition Height="120"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="200"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Rectangle Grid.Row="0" Grid.Column="1" x:Name="PreviewColour" Fill="#FFFF6600" Margin="15" ></Rectangle>
<StackPanel Grid.Row="1" Grid.Column="1">
<TextBlock FontSize="12">Color</TextBlock>
<TextBox x:Name="HexColour" Text="#FFFF6600" Height="30" Width="160" Margin="5" HorizontalAlignment="Left" FontSize="11"></TextBox>
</StackPanel>
<StackPanel Grid.Row="0" Grid.Column="0" Grid.RowSpan="2" VerticalAlignment="Center">
<TextBlock Text="Alpha" FontSize="11" Margin="10,15,0,0"/>
<Slider x:Name="SliderAlpha" Margin="20,0,10,0" Maximum="255" Value="255" ValueChanged="Slider_ValueChanged"/>
<TextBlock Text="Red" FontSize="11" Margin="10,15,0,0"/>
<Slider x:Name="SliderRed" Margin="20,0,10,0" Maximum="255" Value="255" ValueChanged="Slider_ValueChanged"/>
<TextBlock Text="Green" FontSize="11" Margin="10,15,0,0"/>
<Slider x:Name="SliderGreen" Margin="20,0,10,0" Maximum="255" Value="102" ValueChanged="Slider_ValueChanged"/>
<TextBlock Text="Blue" FontSize="11" Margin="10,15,0,0"/>
<Slider x:Name="SliderBlue" Margin="20,0,10,0" Maximum="255" Value="0" ValueChanged="Slider_ValueChanged"/>
</StackPanel>
</Grid>
如果安装了 ,关掉项目 重新打开一次,重新生成下 试试