要在Android Leanback(Android TV)应用程序中更改滚动条拇指的可见性,您可以使用自定义的ScrollbarThumbDrawable和ScrollbarTrackDrawable,并将其应用于RecyclerView或其他支持滚动的视图。
首先,创建一个自定义的ScrollbarThumbDrawable类,它将控制滚动条拇指的可见性。以下是一个示例实现:
public class CustomScrollbarThumbDrawable extends StateListDrawable {
private boolean isVisible = true;
public CustomScrollbarThumbDrawable(Drawable drawable) {
super();
addState(new int[]{android.R.attr.state_enabled}, drawable);
}
@Override
public boolean setVisible(boolean visible, boolean restart) {
isVisible = visible;
return super.setVisible(visible, restart);
}
@Override
public void draw(Canvas canvas) {
if (isVisible) {
super.draw(canvas);
}
}
}
接下来,创建一个自定义的ScrollbarTrackDrawable类,它将控制滚动条轨道的可见性。以下是一个示例实现:
public class CustomScrollbarTrackDrawable extends StateListDrawable {
private boolean isVisible = true;
public CustomScrollbarTrackDrawable(Drawable drawable) {
super();
addState(new int[]{android.R.attr.state_enabled}, drawable);
}
@Override
public boolean setVisible(boolean visible, boolean restart) {
isVisible = visible;
return super.setVisible(visible, restart);
}
@Override
public void draw(Canvas canvas) {
if (isVisible) {
super.draw(canvas);
}
}
}
然后,在您的Activity或Fragment中,将自定义的ScrollbarThumbDrawable和ScrollbarTrackDrawable应用于RecyclerView的滚动条。以下是一个示例:
// 创建自定义的ScrollbarThumbDrawable和ScrollbarTrackDrawable
CustomScrollbarThumbDrawable thumbDrawable = new CustomScrollbarThumbDrawable(
getResources().getDrawable(R.drawable.scrollbar_thumb));
CustomScrollbarTrackDrawable trackDrawable = new CustomScrollbarTrackDrawable(
getResources().getDrawable(R.drawable.scrollbar_track));
// 设置RecyclerView的垂直滚动条
RecyclerView recyclerView = findViewById(R.id.recyclerView);
recyclerView.setVerticalScrollBarEnabled(true);
recyclerView.setScrollbarThumbDrawable(thumbDrawable);
recyclerView.setScrollbarTrackDrawable(trackDrawable);
在上面的示例中,您需要将R.drawable.scrollbar_thumb和R.drawable.scrollbar_track替换为您自己的滚动条拇指和轨道的图像资源。
通过这种方式,您可以在Android Leanback(Android TV)应用程序中控制滚动条拇指和轨道的可见性。