Question

我正在使用.NET 3.5

我有一个DataGridTextColumn，我想在该列的值为false时将背景颜色变为红色。我已经在XMAL中看到了这一点，但无法弄清楚如何在代码中执行此操作

DataGridTextColumn column = new DataGridTextColumn() { Header = "Can Connect", Binding = new Binding("CanConnect") };
//How to add the converter here so that the background of the cell turns red when CanConnect = false?

    public class IsConnectedConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            bool input = (bool)value;
            switch (input)
            {
                case true:
                    return DependencyProperty.UnsetValue;
                default:
                    return Brushes.Red;
            }
        }
    }

Answer 1

使用Binding课程的Converter property：

new Binding("CanConnect") {
    Converter = new IsConnectedConverter()
}

在您的代码中，您将绑定分配给Binding的{{1}}属性，但该属性仅控制单元格的内容。对于单元格的视觉外观，您将需要一个样式，也可以在代码隐藏中设置：

DataGridTextColumn

在该代码中，Style st = new Style(typeof(DataGridCell)); st.Setters.Add(new Setter(Control.BackgroundProperty, binding)); column.CellStyle = st;将是一个带有新binding对象的变量（或者上面的构造函数和初始化调用）。正如docs on DataGridTextColumn.CellStyle所描述的，样式的目标类型必须是Binding，并且该类继承自DataGridCell，我们可以为Control的依赖属性添加setter，例如Control。

我恐怕现在无法测试此代码;我希望它能让你了解如何继续。

Answer 2

var binding = new Binding("CanConnect") {
   Converter = new IsConnectedConverter()
};
DataGridTextColumn column = new DataGridTextColumn() { Header = "Can Connect", Binding = binding };

Answer 3

要设置Converter，您可以使用Converter类的Binding属性：

DataGridTextColumn column = new DataGridTextColumn();
column.Header = "Can Connect";
Binding binding = new Binding("CanConnect");
binding.Converter = new IsConnectedConverter();
column.Binding = binding;

你不应该将switch用于布尔变量。这样更好：

public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
    bool input = (bool)value;
    if (input)
    {
       return DependencyProperty.UnsetValue;
    }
    return Brushes.Red;
}

Answer 4

只是添加到此。我需要将Converter设置为样式的绑定而不是列的绑定：

        Binding columnBinding = new Binding("CanConnect");
        Binding styleBinding = new Binding("CanConnect") { Converter = new IsConnectedConverter()}; 
        Style st = new Style(typeof(DataGridCell));
        st.Setters.Add(new Setter(Control.BackgroundProperty, styleBinding));
        column.CellStyle = st;
        column.Binding = columnBinding;
        dataGrid.Columns.Add(column);

在代码中动态添加IValueConverter

4 个答案: