android 快速实现 垂直SeekBar（VerticalSeekBar）

1.话不多说上源码：

package com.example.widget;import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.view.MotionEvent;/*** Class to create a vertical slider*/
public class VerticalSeekBar extends androidx.appcompat.widget.AppCompatSeekBar {public VerticalSeekBar(Context context) {super(context);}public VerticalSeekBar(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);}public VerticalSeekBar(Context context, AttributeSet attrs) {super(context, attrs);}protected void onSizeChanged(int w, int h, int oldw, int oldh) {super.onSizeChanged(h, w, oldh, oldw);}@Overrideprotected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(heightMeasureSpec, widthMeasureSpec);setMeasuredDimension(getMeasuredHeight(), getMeasuredWidth());}protected void onDraw(Canvas c) {c.rotate(-90);c.translate(-getHeight(), 0);super.onDraw(c);}@Overridepublic boolean onTouchEvent(MotionEvent event) {if (!isEnabled()) {return false;}switch (event.getAction()) {case MotionEvent.ACTION_DOWN:case MotionEvent.ACTION_MOVE:case MotionEvent.ACTION_UP:setProgress(getMax() - (int) (getMax() * event.getY() / getHeight()));onSizeChanged(getWidth(), getHeight(), 0, 0);break;case MotionEvent.ACTION_CANCEL:break;}return true;}
}

2.布局中使用：

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="wrap_content"android:layout_height="wrap_content"android:background="@android:color/darker_gray"><com.example.widget.VerticalSeekBarandroid:id="@+id/sb_volume"android:layout_width="40dp"android:layout_height="180dp"/>
</FrameLayout>