How can I make an Android seek-bar move smoothly?

问题:

I'm trying to make a SeekBar move more smoothly than just jumping straight to the position. I'm doing this as I've got a SeekBar with 3 options for a slider-type implementation.

I'm looking to create a nice smooth slider with 3 options "Yes", "No option", "No" for a feature in my app and a SeekBar looks the best and easiest way.

I've tried looking at Android Animation and it seems a tad bit complex, so if anyone could be of any help that would be nice :)

回答1:

I found the following solution to make the seekbar move smoothly, yet still snap to a limited range of values. Assuming you have the following views in your layout:

<SeekBar
  android:id="@+id/sldProgress"
  style="@style/MySliderStyle"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:max="100"
  android:progress="50" />

<TextView
  android:id="@+id/lblProgress"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="5" />

You can use the following code in your activity (change the value of android:max in the above xml, and the smoothness factor in the code below according to your needs - higher values = smoother):

public class MyActivity extends Activity {
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    sliderListener sldListener = new sliderListener();
    SeekBar sldProgress = (SeekBar) findViewById(R.id.sldProgress);
    sldProgress.setOnSeekBarChangeListener(sldListener);
  }
  private class sliderListener implements OnSeekBarChangeListener {
    private int smoothnessFactor = 10;
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
      progress = Math.round(progress / smoothnessFactor);
      TextView lblProgress = (TextView) findViewById(R.id.lblProgress);
      lblProgress.setText(String.valueOf(progress));
    }

    public void onStartTrackingTouch(SeekBar seekBar) {
    }

    public void onStopTrackingTouch(SeekBar seekBar) {
      seekBar.setProgress(Math.round((seekBar.getProgress() + (smoothnessFactor / 2)) / smoothnessFactor) * smoothnessFactor);
    }
  }
}

回答2:

Built my own control. Job done :) Code here

回答3:

You don't need to build anything by yourself just user android animation it will do the thing for you

The code written in kotlin

    mySeekbar.setOnSeekBarChangeListener(object : SeekBar.OnSeekBarChangeListener {
        override fun onProgressChanged(seekBar: SeekBar, progress: Int, fromUser: Boolean) {
            //Todo: code
        }

        override fun onStartTrackingTouch(seekBar: SeekBar?) {
        }

        override fun onStopTrackingTouch(seekBar: SeekBar) {
            if (seekBar.progress > 70) {
                ObjectAnimator.ofInt(seekBar, "progress", 100).setDuration(100).start()
            } else if (seekBar.progress < 30) {
                ObjectAnimator.ofInt(seekBar, "progress", 0).setDuration(100).start()
            } else {
                ObjectAnimator.ofInt(seekBar, "progress", 50).setDuration(100).start()
            }
        }
    })

回答4:

This works fine for me, quite simple and straight forward.

if (currentPosition > 0) {
    ObjectAnimator animation = ObjectAnimator.ofInt(seekBar, "progress", currentPosition);
    animation.setDuration(400);
    animation.setInterpolator(new DecelerateInterpolator());
    animation.start();
}

回答5:

Create a custom SeekBar

public class SmoothSeekBar extends AppCompatSeekBar implements SeekBar.OnSeekBarChangeListener {

private SeekBar.OnSeekBarChangeListener mOnSeekBarChangeListener;

private boolean mNeedCallListener = true;

private ValueAnimator mAnimator;

public SmoothSeekBar(Context context) {
    super(context);
    init(context);
}

public SmoothSeekBar(Context context, AttributeSet attrs) {
    super(context, attrs);
    init(context);
}

public SmoothSeekBar(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    init(context);
}


public void init(Context context) {
    Context mContext = context;
}

@Override
public void setOnSeekBarChangeListener(
        SeekBar.OnSeekBarChangeListener onSeekBarChangeListener) {
    mOnSeekBarChangeListener = onSeekBarChangeListener;
    super.setOnSeekBarChangeListener(this);
}

@Override
public void setProgress(final int progress) {
    final int currentProgress = getProgress();
    if (mAnimator != null) {
        mAnimator.cancel();
        mAnimator.removeAllUpdateListeners();
        mAnimator.removeAllListeners();
        mAnimator = null;
        mNeedCallListener = true;
    }
    mAnimator = ValueAnimator.ofInt(currentProgress, progress);
    mAnimator.setDuration(getResources().getInteger(android.R.integer.config_longAnimTime));
    mAnimator.setInterpolator(new AccelerateDecelerateInterpolator());
    mAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator animation) {
            int value = (int) animation.getAnimatedValue();
            if (value == progress) {
                mNeedCallListener = true;
            } else {
                mNeedCallListener = false;
            }
            Logger.e("ProgressBar value ", value + "");
            SmoothSeekBar.super.setProgress(value);
        }
    });
    mAnimator.start();

}

@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
    if (fromUser || mNeedCallListener) {
        if (mOnSeekBarChangeListener != null) {
            mOnSeekBarChangeListener.onProgressChanged(seekBar, progress, fromUser);
        }
    }
}

@Override
public void onStartTrackingTouch(SeekBar seekBar) {
    if (mOnSeekBarChangeListener != null) {
        mOnSeekBarChangeListener.onStartTrackingTouch(seekBar);
    }
}

@Override
public void onStopTrackingTouch(SeekBar seekBar) {
    if (mOnSeekBarChangeListener != null) {
        mOnSeekBarChangeListener.onStopTrackingTouch(seekBar);
    }
}
}

Now add SeekBar in xml and enjoy

 <com.yourPackage.SmoothSeekBar
    android:id="@+id/seekBar"
    style="?android:attr/progressBarStyleHorizontal"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"/>