RAD Studio中自定义ListView成员获取及DynamicAppearance项赋值问题

Hey there! Let's break down your RAD Studio ListView questions with practical, actionable solutions:

When working with custom ListView setups—whether it’s a fully custom ListViewItem class or a DynamicAppearance-based layout—you can’t rely on direct member access like the default Text property. Here are the two most common scenarios:

• If you’re using a custom ListViewItem class:
  First, ensure your custom class is properly registered with the ListView. When adding items, cast the returned TListViewItem to your custom type to access its unique members:

  // Assume your custom class is named TMyCustomListViewItem
  TMyCustomListViewItem* customItem = dynamic_cast<TMyCustomListViewItem*>(ListView->Items->Add());
  if (customItem) {
      // Access your custom properties/methods here
      customItem->MyCustomText = "Custom Content";
  }
  

• If you’re using DynamicAppearance (like your second question):
  All visual elements in a DynamicAppearance are stored as Drawable objects in the item’s Objects collection. You’ll need to locate the specific drawable by its name (matching what you set in the designer) to modify it.

The error you’re seeing happens because Text1 isn’t a direct member of TListViewItem—it’s a separate TTextObject drawable in the DynamicAppearance layout. Here’s the correct way to set its value:

First, double-check that in the ListView designer, your secondary text control has its Name property set to "Text1" (this is case-sensitive!). Then use this code:

TListViewItem* item = ListView->Items->Add();
// Set the default Text property as you did before
item->Text = "MyText";

// Locate the Text1 drawable and cast it to TTextObject
TTextObject* text1Drawable = dynamic_cast<TTextObject*>(item->Objects->FindDrawable("Text1"));
// Always check the cast result to avoid runtime errors
if (text1Drawable) {
    text1Drawable->Text = "Text1 Content";
}

Why this works: DynamicAppearance builds items from individual drawable components (text, images, etc.) grouped under the item’s Objects property. FindDrawable() retrieves the component by its name, and casting it to TTextObject lets you modify its Text property just like any other text control.

内容的提问来源于stack exchange，提问作者Sarthak mirajkar