我有一个自定义绘制的拇指一个搜索栏，我想隐藏它基于另一个控制我必须要能够显示/。

I have a SeekBar with a custom drawable for the Thumb, and I would like to be able to show/hide it based on another control I have.

我试图加载从资源的绘制，然后使用SeekBar.setThumb（）与绘制，或者为null。

I have tried loading the drawable from resources, and then using SeekBar.setThumb() with the drawable, or null.

这是隐藏它（设置为null），但我永远不能拿回来。

That hides it (the set to null), but I can never get it back.

推荐答案

要做到这一点，最好的方法是设置可绘制从XML拇指（因为我是做所有沿），然后当你想隐藏/显示拇指绘制，只需操纵它的alpha值：

The best way to do this is to set the drawable for the thumb from XML (as I was doing all along) and then when you want to hide/show the Thumb drawable, just manipulate it's alpha value:

// Hide the thumb drawable if the SeekBar is disabled
if (enabled) {
    seekBar.getThumb().mutate().setAlpha(255);
} else {
    seekBar.getThumb().mutate().setAlpha(0);
}