Android Seekbar - 只允许通过滑块来更改？

Question

我有一个seekbar滑动条，我希望只允许使用拇指/手柄部分来更改它。如果用户在其他任何地方点击，我希望忽略该点击。

是否有固有属性可实现此功能？如果没有，我已经知道可以设置onTouch监听器并返回true 来“禁用”它，但是否有一种方法可以检测到拇指被点击，以便我可以告诉onTouch在这种情况下返回false？

- bugfixr

---

我也想知道这个答案... - Josh

你可以在这里看到我的答案https://dev59.com/1G435IYBdhLWcg3w7k2b#16992969 - Slim

Answer 1

我猜你想通过代码来改变缩略图位置，但这是受用户限制的。所以尝试使用以下方法，可能有帮助。

            myseekBar.setOnSeekBarChangeListener( new OnSeekBarChangeListener() {

            int originalProgress;

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
                originalProgress = seekBar.getProgress();
            }

            @Override
            public void onProgressChanged(SeekBar seekBar, int arg1, boolean fromUser) {
                if( fromUser == true){
                    seekBar.setProgress(originalProgress);
                }               
            }
        });

- βhargavḯ

Answer 2

// I solved this problem.

private int mOriginProgress;
private boolean mIsDrag;

@Override
public void onStartTrackingTouch(SeekBar seekBar) {
    mIsTouched = true;
    mOriginProgress = seekBar.getProgress();
}

@Override
public void onProgressChanged(SeekBar seekBar, int p, boolean fromUser) {
    if (mOriginProgress == p) {
        return;
    }

    if (mIsDrag) {
        // do something
    } else {
        if (Math.abs(mOriginProgress - p) > 5) {
            seekBar.setProgress(mOriginProgress);
        } else {
            mIsDrag = true;
        }
    }
}

@Override
public void onStopTrackingTouch(SeekBar seekBar) {
    mIsDrag = false;
}

- lisperl

Answer 3

我曾经遇到过同样的问题，我使用了一个简单的逻辑来比较新进度和旧进度，最终解决了这个问题。以下是我的代码，用于实现一个垂直滑块，只有在用户点击拇指时才允许更改值。

这就是诀窍：

int tempProgress = (getMax() - (int) (getMax() * event.getY() / getHeight()));
            int diff = Math.abs(tempProgress - progress);
            if ( diff > 7 && !isMoving) return true;
            isMoving = true;

这是所有组件的源代码：

 package android.widget;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.MotionEvent;

public class VerticalSeekBar extends SeekBar {

    private OnSeekBarChangeListener onChangeListener;
    private int progress = 0;
    private Drawable mThumb;
    private boolean isMoving;

    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 void setOnSeekBarChangeListener(OnSeekBarChangeListener onChangeListener){
        this.onChangeListener = onChangeListener;
    }

    public void setThumb(Drawable thumb) {
        if (thumb != null) {
            thumb.setCallback(this);
        }
        super.setThumb(thumb);
        mThumb = thumb;
        mThumb.setCallback(this);
    }


    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (!isEnabled()) {
            return false;
        }

        switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:

            if ( onChangeListener!= null)onChangeListener.onStartTrackingTouch(this);
            setPressed(true);
            setSelected(true);
            break;
        case MotionEvent.ACTION_MOVE:
            int tempProgress = (getMax() - (int) (getMax() * event.getY() / getHeight()));
            int diff = Math.abs(tempProgress - progress);
            if ( diff > 7 && !isMoving) return true;
            isMoving = true;
            progress = getMax() - (int) (getMax() * event.getY() / getHeight());
            if(progress < 18) {progress = 18;}
            if(progress > getMax()) {progress = getMax();}
            setProgressAndThumb(progress);
            setPressed(true);
            setSelected(true);
            break;
        case MotionEvent.ACTION_UP:
            isMoving = false;
            if ( onChangeListener!= null)onChangeListener.onStopTrackingTouch(this);
            setPressed(false);
            setSelected(false);
            break;
        case MotionEvent.ACTION_CANCEL:
            isMoving = false;
            super.onTouchEvent(event);
            setPressed(false);
            setSelected(false);
            break;
        }
        return true;
    }

    public synchronized void setProgressAndThumb(int progress) {
        setProgress(progress);
        onSizeChanged(getWidth(), getHeight() , 0, 0);
        if ( onChangeListener!= null) onChangeListener.onProgressChanged(this, progress, true);
    }

    @Override
    public synchronized void setProgress(int progress) {
        this.progress =progress;
        super.setProgress(progress);
         if ( onChangeListener !=null) onChangeListener.onProgressChanged(this, progress, true);
    }

    public synchronized void setMaximum(int maximum) {
        setMax(maximum);
    }

    public synchronized int getMaximum() {
        return getMax();
    }
}

祝好！

- Deivison Sporteman