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using System.Collections.Generic;
using Unity.UIWidgets.foundation;
using Unity.UIWidgets.widgets;
namespace Unity.UIWidgets.material {
public static class MaterialDebug {
public static bool debugCheckHasMaterial(BuildContext context) {
D.assert(() => {
if (!(context.widget is Material) && context.ancestorWidgetOfExactType(typeof(Material)) == null) {
string message = "No Material widget found.";
message += context.widget.GetType() + " widgets require a Material widget ancestor.";
message += "In material design, most widgets are conceptually \"printed\" on " +
"a sheet of material. In Flutter\'s material library, that " +
"material is represented by the Material widget. It is the " +
"Material widget that renders ink splashes, for instance. " +
"Because of this, many material library widgets require that " +
"there be a Material widget in the tree above them.";
message += "To introduce a Material widget, you can either directly " +
"include one, or use a widget that contains Material itself, " +
"such as a Card, Dialog, Drawer, or Scaffold.";
message += "The specific widget that could not find a Material ancestor was:";
message += context.widget.ToString();
List<Widget> ancestors = new List<Widget>();
context.visitAncestorElements((Element element) => {
ancestors.Add(element.widget);
return true;
});
if (ancestors.isNotEmpty()) {
message += "The ancestors of this widget were:";
foreach (Widget ancestor in ancestors) {
message += "\n $ancestor";
}
}
else {
message += "This widget is the root of the tree, so it has no " +
"ancestors, let alone a \"Material\" ancestor.";
}
throw new UIWidgetsError(message);
}
return true;
});
return true;
}
}
}