FM滾動是出現豎線的地方

package com.example.testdrawview;

import com.example.testdrawview.TuneWheel.OnTuneWheelValueChangedListener;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.app.Activity;
import android.view.Menu;
import android.view.View;

public class MainActivity extends Activity implements OnTuneWheelValueChangedListener{

private TuneWheel mTuneWheel;
private static final int MSG_TUNE = 4;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

mTuneWheel = (TuneWheel)findViewById(R.id.tune_wheel);
        mTuneWheel.setOnValueChangedListener(this);
}

@Override
public void onTuneWheelValueChanged(View v, float changedBy) {
// TODO Auto-generated method stub
Message msg = mHandler.obtainMessage(MSG_TUNE);
        Bundle data = new Bundle();
        float freq = adjustFreq(WheelConfig.format(changedBy));

        data.putFloat("freq", freq);
        msg.setData(data);
        mHandler.sendMessage(msg);
    }

private float adjustFreq(float freq) {
        float result = ((int)(freq * 10)) / 10f;
        if (result < WheelConfig.RADIO_MIN_FREQUENCY)
            result = WheelConfig.RADIO_MIN_FREQUENCY;

        if (result > WheelConfig.RADIO_MAX_FREQUENCY)
            result = WheelConfig.RADIO_MAX_FREQUENCY;
        return result;
    }

private Handler mHandler = new Handler(){
        public void handleMessage(Message msg) {
            
            switch(msg.what) {
    
            case MSG_TUNE:
                {
                /* Bundle data = msg.getData();
                    removeMessages(MSG_TUNE);
                    if (mReady) {
                        float freq = data.getFloat("freq");
                        FMPlaySharedPreferences.setTunedFreq(freq);
                        Log.d(LOGTAG,"MSG_TUNE: entering showRadioInfo");
                        setFreqForUi(freq);
                        mService.setFreq(freq);
                    } else {
                        Message message = mHandler.obtainMessage(MSG_TUNE);
                        message.setData(data);
                        sendMessageDelayed(message, CHECK_DELAY);
                    }*/
                }
                break;
            default:
            }
        }
};

}

/**

* Copyright (C) 2009,2010 Thundersoft Corporation

* All rights Reserved

*/

package com.example.testdrawview;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;

public class TuneWheel extends View {

    public interface OnTuneWheelValueChangedListener {
        public void onTuneWheelValueChanged(View v, float changedBy);
    }

    private static final String LOGTAG = "TuneWheel";

    private static final int LINE_SPAN = 8;
    private static final int DRAG_THRESHOLD = 5;
    private static final float CHANGE_THRESHOLD = 0.1f;
    public static final int DIRECTION_PREV = 1;
    public static final int DIRECTION_NEXT = 2;

    private float mLastDragPos;
    private boolean mIsMoving = false;

    private float mCurrentPos = 0;
    private float mCurrentChange = 0;
    private int mDragEnable = DIRECTION_PREV | DIRECTION_NEXT;

    private OnTuneWheelValueChangedListener mListener = null;

    public void setOnValueChangedListener(OnTuneWheelValueChangedListener listener) {
        mListener = listener;
    }

    public void setDragEnable(int direction, boolean enable) {
        if (enable) {
            mDragEnable = mDragEnable | direction;
        } else {
            mDragEnable = mDragEnable ^ direction;
        }
    }

    public boolean getDragEnable(int direction) {
        return (mDragEnable & direction) != 0;
    }

    public TuneWheel(Context context) {
        super(context);
    }

    protected void onDraw(Canvas canvas) {     
        Paint mLinePaint = new Paint();
        mLinePaint.setARGB(0xEC, 0x00, 0, 0);
        mLinePaint.setStrokeWidth(0.5f);
        for (int pos = 0; pos + mCurrentPos < getWidth(); pos += LINE_SPAN) {   //豎線
            canvas.drawLine(pos + mCurrentPos, 0, pos + mCurrentPos, getHeight(), mLinePaint);
        }
    }

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

    public TuneWheel(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public boolean onTouchEvent(MotionEvent event) {
        if (!this.isEnabled())
            return false;

        int action = event.getAction();
                
        switch(action) {
        
        case MotionEvent.ACTION_MOVE:
            float currentDragPos = event.getX();
            
            if (!getDragEnable(getDirection(currentDragPos, mLastDragPos)))
                return false;

            if (!mIsMoving) {
                if (Math.abs(currentDragPos - mLastDragPos) > DRAG_THRESHOLD) {
                    mIsMoving = true;
                    mLastDragPos = currentDragPos;
                } else {
                    return false;
                }
            } else {
                float tempPos = (mCurrentPos + currentDragPos - mLastDragPos) % LINE_SPAN;

                mCurrentChange += calculateChange(currentDragPos, mLastDragPos);
                if (Math.abs(mCurrentChange) > CHANGE_THRESHOLD) {
                    if (mListener != null) {
                        mListener.onTuneWheelValueChanged(this, mCurrentChange);
                    }
                    mCurrentChange = 0;
                }

                mCurrentPos = tempPos;
                invalidate();   //調用onDraw() 出現豎線

                mLastDragPos = currentDragPos;
            }
            break;
      
        }

        return true;
    }

    private int getDirection(float current, float last) {
        return (int)(Math.signum(current - last) + 3) / 2;
    }
 
    private float calculateChange(float current, float last) {
        float sub = current - last;
        return Math.signum(sub) * (float)Math.pow(Math.abs(sub), 1.3) / 100;
    }
}

/**

* Copyright (C) 2009,2010 Thundersoft Corporation

* All rights Reserved

*/

package com.example.testdrawview;

import java.text.DecimalFormat;
import java.lang.Number;
import java.text.ParseException;

public class WheelConfig {
    public static final float RADIO_MIN_FREQUENCY = 87.5f;
    public static final float RADIO_MAX_FREQUENCY = 108.0f;
    
    private static DecimalFormat mFormat = new DecimalFormat("####.0");
    
    private float mFreqSpan;    
    private float mFreqInterval;
    private float mMinFreq;    
    private float mMaxFreq;
    private float mHeadPadding;
    private float mTailPadding;
    
    public void setSpan(float span) {
        mFreqSpan = format(span);
    }

    public static float format(float f) {
        float value = f;
        try {
            Number digit = mFormat.parse(mFormat.format(f));
            value = digit.floatValue();
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return value;
    }
    
    public WheelConfig() {}

    public void setBand(float start, float end) {       
        mMinFreq = format(start);
        mMaxFreq = format(end);
    }
    
    public void setHeadPadding(float padding) {
        mHeadPadding = padding;
    }
    
    public void setTailPadding(float padding) {
        mTailPadding = padding;
    }

    public float[] getBand() {
        float[] value = new float[2];
        value[0] = mMinFreq;
        value[1] = mMaxFreq;
        
        return value;
    }

    public float getSpan() {
        return mFreqSpan;
    }
    
    public void setInterval(float interval) {
        mFreqInterval = format(interval);
    }
    
    public float getInterval() {
        return mFreqInterval;
    }

    public float getHeadPadding() {
        return mHeadPadding;
    }

    public float getTailPadding() {
        return mTailPadding;
    }
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <FrameLayout
        android:layout_x="50dip"
        android:layout_y="291dip"
        android:layout_height="30dip"
        android:layout_width="220dip"
        android:background="@drawable/scroller_bg"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        >
        <com.example.testdrawview.TuneWheel
            android:id="@+id/tune_wheel"
            android:layout_height="fill_parent"
            android:layout_width="fill_parent"
        />
        <ImageView
            android:layout_height="fill_parent"
            android:layout_width="fill_parent"
            android:src="@drawable/tune_wheel_highlight"
        />
    </FrameLayout>

</RelativeLayout>