如何在ListView中设置自定义缩略图以进行快速滚动。
你可以将这个设置写入style.xml文件中
<style name="Theme_app" parent="@android:style/Theme.Holo.Light">
<item name="android:fastScrollThumbDrawable">@drawable/fastscroll_thumb_holo</item>
</style>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_pressed="true" android:drawable="@drawable/fastscroll_thumb_pressed_holo" />
<item android:drawable="@drawable/fastscroll_thumb_default_holo" />
</selector>
从样式中设置Drawable是最好的方法。但是,如果您希望以编程方式实现此操作,这里有两种方法可能会有用:
/**
* Set a ListView or GridView fast scroll thumb image.
*
* @param listView The {@link android.widget.ListView} or {@link android.widget.GridView}
* @param thumb The fast-scroll drawable
* @return {@code true} if successfully set.
*/
public static boolean setFastScrollThumbImage(AbsListView listView, Drawable thumb) {
try {
Field f;
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
f = AbsListView.class.getDeclaredField("mFastScroll");
} else {
f = AbsListView.class.getDeclaredField("mFastScroller");
}
f.setAccessible(true);
Object o = f.get(listView);
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
f = f.getType().getDeclaredField("mThumbImage");
f.setAccessible(true);
ImageView iv = (ImageView) f.get(o);
iv.setImageDrawable(thumb);
} else {
f = f.getType().getDeclaredField("mThumbDrawable");
f.setAccessible(true);
Drawable drawable = (Drawable) f.get(o);
drawable = thumb;
f.set(o, drawable);
}
return true;
} catch (Exception ignored) {
}
return false;
}
/**
* Set a ListView or GridView fast scroll thumb color.
*
* @param listView The {@link android.widget.ListView} or {@link android.widget.GridView}
* @param color The color for the fast-scroll thumb
* @return {@code true} if successfully set.
*/
public static boolean setFastScrollThumbColor(AbsListView listView, int color) {
try {
Field f;
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
f = AbsListView.class.getDeclaredField("mFastScroll");
} else {
f = AbsListView.class.getDeclaredField("mFastScroller");
}
f.setAccessible(true);
Object o = f.get(listView);
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
f = f.getType().getDeclaredField("mThumbImage");
f.setAccessible(true);
ImageView iv = (ImageView) f.get(o);
iv.setColorFilter(color, android.graphics.PorterDuff.Mode.SRC_ATOP);
} else {
f = f.getType().getDeclaredField("mThumbDrawable");
f.setAccessible(true);
final Drawable drawable = (Drawable) f.get(o);
drawable.setColorFilter(color, android.graphics.PorterDuff.Mode.SRC_ATOP);
}
return true;
} catch (Exception ignored) {
}
return false;
}
try {
java.lang.reflect.Field f = AbsListView.class.getDeclaredField("mFastScroller");
f.setAccessible(true);
Object o = f.get(root.findViewById(R.id.beam_contact_listview));
if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
f = f.getType().getDeclaredField("mThumbImage");
} else {
f = f.getType().getDeclaredField("mThumbDrawable");
}
f.setAccessible(true);
Drawable drawable = (Drawable) f.get(o);
drawable = getResources().getDrawable(R.drawable.sv_fastscroll);
f.set(o, drawable);
} catch (Exception e) {
e.printStackTrace();
}
如果您查看Android 2.2r1(修订版1)的源代码,会发现有一个名为android.widget.FastScroller
的类,其中包含方法useThumbDrawable()
。
我刚刚从一个名为MobileBytes的博客下载了该源代码,您可以将其导入到您的项目中并实现它?(或者将您的API升级到2.2 r1)
我正在使用android:fastScrollThumbDrawable
,但我不知道为什么它不起作用,所以在网上搜索时我找到了这里一个硬编码的解决方案。我不知道它是否适用于旧的API,但在我的情况下问题得到了解决。请注意,我将API 18作为目标,并使用API 17的设备进行测试。
代码如下:
try {
Field f = AbsListView.class.getDeclaredField("mFastScroller");
f.setAccessible(true);
Object o = f.get(<<your listView here>>);
f = f.getType().getDeclaredField("mThumbDrawable");
f.setAccessible(true);
Drawable drawable = (Drawable) f.get(o);
drawable = getResources().getDrawable(R.drawable.<<your thumb drawable here can be a selector>>);
f.set(o, drawable);
} catch (Exception e) {
e.printStackTrace();
}