“未将对象引用设置到对象的实例。”,Comobox
在Silverlight中使用到了“Comobox控件”,其用法如下:
前台:
<ComboBox x:Name="cb_chartType" Canvas.Left="87" Canvas.Top="39" Width="96" SelectionChanged="cb_chartType_SelectionChanged">
<ComboBoxItem Content="柱形图" IsSelected="True" />
<ComboBoxItem Content="堆积图"/>
<ComboBoxItem Content="线形图"/>
</ComboBox>
后台:
private void cb_chartType_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
//string type = cb_chartType.SelectedValue.ToString();
//ComboBox box = sender as ComboBox;
TextBlock tbl = cb_chartType.SelectedItem as TextBlock;
[color=#FF0000]问题:在“SL”页面加载时提示错误,“未将对象引用设置到对象的实例。”,请问这是为什么?
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string type = tbl.Text;
DataSeries dataSeries = SLChart.Series[0];
switch (type)
{
case "柱形图":
dataSeries.RenderAs = RenderAs.Column;
break;
case "线性图":
dataSeries.RenderAs = RenderAs.Line;
break;
//case "Pie":
// dataSeries.RenderAs = RenderAs.Pie;
// break;
//case "Bar":
// dataSeries.RenderAs = RenderAs.Bar;
// break;
case "堆积图":
dataSeries.RenderAs = RenderAs.Area;
break;
}
}