Android實現垂直進度條VerticalSeekBar

2019-12-12 00:41:42

字體：大中小

來源：轉載

供稿：網友

本文實例為大家分享了Android實現垂直進度條的具體代碼，供大家參考，具體內容如下

水平的進度條見多了，總會想見個垂直的進度條開開眼。今天咱就試試。
要說原理也簡單，就是把寬高倒置，其他的理論上都不需要動，發現問題再補補也就行了。

官方提供

官方是提供了垂直進度條的例子源碼的，位置在android-sdk-windows/sources/android-23/com/android/example/rscamera/VerticalSeekBar.java，當然首先你SDK中要有Android 6.0。

VerticalSeekBar.java

/** * Class to create a vertical slider */public class VerticalSeekBar extends SeekBar {  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);  }  @Override  protected 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);  }  @Override  public 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;  }}

繼承SeekBar是最簡單快捷的，不用重寫太多方法，只需要把

onMeasure
onSizeChanged
onDraw

三個方法作一些改動；但也有一些問題，比如只能響應onPregress方法，為了讓他能響應onStartTrackingTouch和onStopTrackingTouch方法，只好再加一些代碼，于是有了改進版。

稍作改進

VerticalSeekBar2.java

public class VerticalSeekBar2 extends SeekBar {  private Drawable mThumb;  private OnSeekBarChangeListener mOnSeekBarChangeListener;  public VerticalSeekBar2(Context context) {    super(context);  }  public VerticalSeekBar2(Context context, AttributeSet attrs) {    super(context, attrs);  }  public VerticalSeekBar2(Context context, AttributeSet attrs, int defStyle) {    super(context, attrs, defStyle);  }  public void setOnSeekBarChangeListener(OnSeekBarChangeListener l) {    mOnSeekBarChangeListener = l;  }  protected void onSizeChanged(int w, int h, int oldw, int oldh) {    super.onSizeChanged(h, w, oldh, oldw);  }  @Override  protected 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);  }  void onProgressRefresh(float scale, boolean fromUser) {    Drawable thumb = mThumb;    if (thumb != null) {      setThumbPos(getHeight(), thumb, scale, Integer.MIN_VALUE);      invalidate();    }    if (mOnSeekBarChangeListener != null) {      mOnSeekBarChangeListener.onProgressChanged(this, getProgress(), fromUser);    }  }  private void setThumbPos(int w, Drawable thumb, float scale, int gap) {    int available = w - getPaddingLeft() - getPaddingRight();    int thumbWidth = thumb.getIntrinsicWidth();    int thumbHeight = thumb.getIntrinsicHeight();    int thumbPos = (int) (scale * available + 0.5f);    // int topBound = getWidth() / 2 - thumbHeight / 2 - getPaddingTop();    // int bottomBound = getWidth() / 2 + thumbHeight / 2 - getPaddingTop();    int topBound, bottomBound;    if (gap == Integer.MIN_VALUE) {      Rect oldBounds = thumb.getBounds();      topBound = oldBounds.top;      bottomBound = oldBounds.bottom;    } else {      topBound = gap;      bottomBound = gap + thumbHeight;    }    thumb.setBounds(thumbPos, topBound, thumbPos + thumbWidth, bottomBound);  }  public void setThumb(Drawable thumb) {    mThumb = thumb;    super.setThumb(thumb);  }  void onStartTrackingTouch() {    if (mOnSeekBarChangeListener != null) {      mOnSeekBarChangeListener.onStartTrackingTouch(this);    }  }  void onStopTrackingTouch() {    if (mOnSeekBarChangeListener != null) {      mOnSeekBarChangeListener.onStopTrackingTouch(this);    }  }  private void attemptClaimDrag() {    if (getParent() != null) {      getParent().requestDisallowInterceptTouchEvent(true);    }  }  @Override  public boolean onTouchEvent(MotionEvent event) {    if (!isEnabled()) {      return false;    }    switch (event.getAction()) {    case MotionEvent.ACTION_DOWN:      setPressed(true);      onStartTrackingTouch();      break;    case MotionEvent.ACTION_MOVE:      attemptClaimDrag();      setProgress(getMax() - (int) (getMax() * event.getY() / getHeight()));      break;    case MotionEvent.ACTION_UP:      onStopTrackingTouch();      setPressed(false);      break;    case MotionEvent.ACTION_CANCEL:      onStopTrackingTouch();      setPressed(false);      break;    }    return true;  }

為了響應另外兩個不知道怎么就被onPregress拋棄的方法，添了這么多代碼真是罪過，不過都是從SeekBar的父類AbsSeekBar中仿寫過來的，邏輯稍作改動就能用。

對比測試

上圖。