android 双向滑动 seekbar
实现原理：
1、自定义View，在onDraw(Canvas canvas)中，画出2个Drawable滑动块，2个Drawable滑动条，2个Paint（text）
2、监听onTouchEvent()事件，修改滑块和滑动条的坐标，调用invalidate()来更新界面
使用方法
1、自定义View SeekBarPressure.class
package xxxxxxxxx import android.content.Context; import android.content.res.Resources; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.drawable.Drawable; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.View; import java.math.BigDecimal; import com.zjcpo.mobileapp.R; public class SeekBarPressure extends View { private static final String TAG = "SeekBarPressure"; private static final int CLICK_ON_LOW = 1; //点击在前滑块上 private static final int CLICK_ON_HIGH = 2; //点击在后滑块上 private static final int CLICK_IN_LOW_AREA = 3; private static final int CLICK_IN_HIGH_AREA = 4; private static final int CLICK_OUT_AREA = 5; private static final int CLICK_INVAILD = 0; /* * private static final int[] PRESSED_STATE_SET = { * android.R.attr.state_focused, android.R.attr.state_pressed, * android.R.attr.state_selected, android.R.attr.state_window_focused, }; */ private static final int[] STATE_NORMAL = {}; private static final int[] STATE_PRESSED = { android.R.attr.state_pressed, android.R.attr.state_window_focused, }; private Drawable hasScrollBarBg; //滑动条滑动后背景图 private Drawable notScrollBarBg; //滑动条未滑动背景图 private Drawable mThumbLow; //前滑块 private Drawable mThumbHigh; //后滑块 private int mScollBarWidth; //控件宽度=滑动条宽度+滑动块宽度 private int mScollBarHeight; //滑动条高度 private int mThumbWidth; //滑动块宽度 private int mThumbHeight; //滑动块高度 private double mOffsetLow = 0; //前滑块中心坐标 private double mOffsetHigh = 0; //后滑块中心坐标 private int mDistance = 0; //总刻度是固定距离 两边各去掉半个滑块距离 private int mThumbMarginTop = 30; //滑动块顶部距离上边框距离，也就是距离字体顶部的距离 private int mFlag = CLICK_INVAILD; private OnSeekBarChangeListener mBarChangeListener; private double defaultScreenLow = 0; //默认前滑块位置百分比 private double defaultScreenHigh = 100; //默认后滑块位置百分比 private boolean isEdit = false; //输入框是否正在输入 public SeekBarPressure(Context context) { this(context, null); } public SeekBarPressure(Context context, AttributeSet attrs) { this(context, attrs, 0); } public SeekBarPressure(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); // this.setBackgroundColor(Color.BLACK); Resources resources = getResources(); notScrollBarBg = resources.getDrawable(R.drawable.seekbarpressure_bg_progress); hasScrollBarBg = resources.getDrawable(R.drawable.seekbarpressure_bg_normal); mThumbLow = resources.getDrawable(R.drawable.seekbarpressure_thumb); mThumbHigh = resources.getDrawable(R.drawable.seekbarpressure_thumb); mThumbLow.setState(STATE_NORMAL); mThumbHigh.setState(STATE_NORMAL); mScollBarWidth = notScrollBarBg.getIntrinsicWidth(); mScollBarHeight = notScrollBarBg.getIntrinsicHeight(); mThumbWidth = mThumbLow.getIntrinsicWidth(); mThumbHeight = mThumbLow.getIntrinsicHeight(); } //默认执行，计算view的宽高,在onDraw()之前 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { int width = measureWidth(widthMeasureSpec); // int height = measureHeight(heightMeasureSpec); mScollBarWidth = width; mOffsetHigh = width - mThumbWidth / 2; mOffsetLow = mThumbWidth / 2; mDistance = width - mThumbWidth; mOffsetLow = formatDouble(defaultScreenLow / 100 * (mDistance ))+ mThumbWidth / 2; mOffsetHigh = formatDouble(defaultScreenHigh / 100 * (mDistance)) + mThumbWidth / 2; setMeasuredDimension(width, mThumbHeight + mThumbMarginTop+2); } private int measureWidth(int measureSpec) { int specMode = MeasureSpec.getMode(measureSpec); int specSize = MeasureSpec.getSize(measureSpec); //wrap_content if (specMode == MeasureSpec.AT_MOST) { } //fill_parent或者精确值 else if (specMode == MeasureSpec.EXACTLY) { } return specSize; } private int measureHeight(int measureSpec) { int specMode = MeasureSpec.getMode(measureSpec); int specSize = MeasureSpec.getSize(measureSpec); int defaultHeight = 100; //wrap_content if (specMode == MeasureSpec.AT_MOST) { } //fill_parent或者精确值 else if (specMode == MeasureSpec.EXACTLY) { defaultHeight = specSize; } return defaultHeight; } protected void onLayout(boolean changed, int l, int t, int r, int b) { super.onLayout(changed, l, t, r, b); } protected void onDraw(Canvas canvas) { super.onDraw(canvas); Paint text_Paint = new Paint(); text_Paint.setTextAlign(Paint.Align.CENTER); text_Paint.setColor(Color.RED); text_Paint.setTextSize(20); int aaa = mThumbMarginTop + mThumbHeight / 2 - mScollBarHeight / 2; int bbb = aaa + mScollBarHeight; //白色，不会动 notScrollBarBg.setBounds(mThumbWidth / 2, aaa, mScollBarWidth - mThumbWidth / 2, bbb); notScrollBarBg.draw(canvas); //蓝色，中间部分会动 hasScrollBarBg.setBounds((int)mOffsetLow, aaa, (int)mOffsetHigh, bbb); hasScrollBarBg.draw(canvas); //前滑块 mThumbLow.setBounds((int)(mOffsetLow - mThumbWidth / 2), mThumbMarginTop, (int)(mOffsetLow + mThumbWidth / 2), mThumbHeight + mThumbMarginTop); mThumbLow.draw(canvas); //后滑块 mThumbHigh.setBounds((int)(mOffsetHigh - mThumbWidth / 2), mThumbMarginTop, (int)(mOffsetHigh + mThumbWidth / 2), mThumbHeight + mThumbMarginTop); mThumbHigh.draw(canvas); double progressLow = formatDouble((mOffsetLow - mThumbWidth / 2) * 100 / mDistance); double progressHigh = formatDouble((mOffsetHigh - mThumbWidth / 2) * 100 / mDistance); // Log.d(TAG, "onDraw-->mOffsetLow: " + mOffsetLow + " mOffsetHigh: " + mOffsetHigh + " progressLow: " + progressLow + " progressHigh: " + progressHigh); canvas.drawText((int) progressLow + "", (int)mOffsetLow - 2 - 2, 15, text_Paint); canvas.drawText((int) progressHigh + "", (int)mOffsetHigh - 2, 15, text_Paint); if (mBarChangeListener != null) { if (!isEdit) { mBarChangeListener.onProgressChanged(this, progressLow, progressHigh); } } } @Override public boolean onTouchEvent(MotionEvent e) { //按下 if (e.getAction() == MotionEvent.ACTION_DOWN) { if (mBarChangeListener != null) { mBarChangeListener.onProgressBefore(); isEdit = false; } mFlag = getAreaFlag(e); // Log.d(TAG, "e.getX: " + e.getX() + "mFlag: " + mFlag); // Log.d("ACTION_DOWN", "------------------"); if (mFlag == CLICK_ON_LOW) { mThumbLow.setState(STATE_PRESSED); } else if (mFlag == CLICK_ON_HIGH) { mThumbHigh.setState(STATE_PRESSED); } else if (mFlag == CLICK_IN_LOW_AREA) { mThumbLow.setState(STATE_PRESSED); //如果点击0-mThumbWidth/2坐标 if (e.getX() < 0 || e.getX() <= mThumbWidth/2) { mOffsetLow = mThumbWidth/2; } else if (e.getX() > mScollBarWidth - mThumbWidth/2) { // mOffsetLow = mDistance - mDuration; mOffsetLow = mThumbWidth/2 + mDistance; } else { mOffsetLow = formatDouble(e.getX()); // if (mOffsetHigh<= mOffsetLow) { // mOffsetHigh = (mOffsetLow + mDuration <= mDistance) ? (mOffsetLow + mDuration) // : mDistance; // mOffsetLow = mOffsetHigh - mDuration; // } } } else if (mFlag == CLICK_IN_HIGH_AREA) { mThumbHigh.setState(STATE_PRESSED); // if (e.getX() < mDuration) { // mOffsetHigh = mDuration; // mOffsetLow = mOffsetHigh - mDuration; // } else if (e.getX() >= mScollBarWidth - mThumbWidth/2) { // mOffsetHigh = mDistance + mThumbWidth/2; if(e.getX() >= mScollBarWidth - mThumbWidth/2) { mOffsetHigh = mDistance + mThumbWidth/2; } else { mOffsetHigh = formatDouble(e.getX()); // if (mOffsetHigh <= mOffsetLow) { // mOffsetLow = (mOffsetHigh - mDuration >= 0) ? (mOffsetHigh - mDuration) : 0; // mOffsetHigh = mOffsetLow + mDuration; // } } } //设置进度条 refresh(); //移动move } else if (e.getAction() == MotionEvent.ACTION_MOVE) { // Log.d("ACTION_MOVE", "------------------"); if (mFlag == CLICK_ON_LOW) { if (e.getX() < 0 || e.getX() <= mThumbWidth/2) { mOffsetLow = mThumbWidth/2; } else if (e.getX() >= mScollBarWidth - mThumbWidth/2) { mOffsetLow = mThumbWidth/2 + mDistance; mOffsetHigh = mOffsetLow; } else { mOffsetLow = formatDouble(e.getX()); if (mOffsetHigh - mOffsetLow <= 0) { mOffsetHigh = (mOffsetLow <= mDistance+mThumbWidth/2) ? (mOffsetLow) : (mDistance+mThumbWidth/2); } } } else if (mFlag == CLICK_ON_HIGH) { if (e.getX() < mThumbWidth/2) { mOffsetHigh = mThumbWidth/2; mOffsetLow = mThumbWidth/2; } else if (e.getX() > mScollBarWidth - mThumbWidth/2) { mOffsetHigh = mThumbWidth/2 + mDistance; } else { mOffsetHigh = formatDouble(e.getX()); if (mOffsetHigh - mOffsetLow <= 0) { mOffsetLow = (mOffsetHigh >= mThumbWidth/2) ? (mOffsetHigh) : mThumbWidth/2; } } } //设置进度条 refresh(); //抬起 } else if (e.getAction() == MotionEvent.ACTION_UP) { // Log.d("ACTION_UP", "------------------"); mThumbLow.setState(STATE_NORMAL); mThumbHigh.setState(STATE_NORMAL); if (mBarChangeListener != null) { mBarChangeListener.onProgressAfter(); } //这两个for循环 是用来自动对齐刻度的，注释后，就可以自由滑动到任意位置 // for (int i = 0; i < money.length; i++) { // if(Math.abs(mOffsetLow-i* ((mScollBarWidth-mThumbWidth)/ (money.length-1)))<=(mScollBarWidth-mThumbWidth)/(money.length-1)/2){ // mprogressLow=i; // mOffsetLow =i* ((mScollBarWidth-mThumbWidth)/(money.length-1)); // invalidate(); // break; // } // } // // for (int i = 0; i < money.length; i++) { // if(Math.abs(mOffsetHigh-i* ((mScollBarWidth-mThumbWidth)/(money.length-1) ))<(mScollBarWidth-mThumbWidth)/(money.length-1)/2){ // mprogressHigh=i; // mOffsetHigh =i* ((mScollBarWidth-mThumbWidth)/(money.length-1)); // invalidate(); // break; // } // } } return true; } public int getAreaFlag(MotionEvent e) { int top = mThumbMarginTop; int bottom = mThumbHeight + mThumbMarginTop; if (e.getY() >= top && e.getY() <= bottom && e.getX() >= (mOffsetLow - mThumbWidth / 2) && e.getX() <= mOffsetLow + mThumbWidth / 2) { return CLICK_ON_LOW; } else if (e.getY() >= top && e.getY() <= bottom && e.getX() >= (mOffsetHigh - mThumbWidth / 2) && e.getX() <= (mOffsetHigh + mThumbWidth / 2)) { return CLICK_ON_HIGH; } else if (e.getY() >= top && e.getY() <= bottom && ((e.getX() >= 0 && e.getX() < (mOffsetLow - mThumbWidth / 2)) || ((e.getX() > (mOffsetLow + mThumbWidth / 2)) && e.getX() <= ((double) mOffsetHigh + mOffsetLow) / 2))) { return CLICK_IN_LOW_AREA; } else if (e.getY() >= top && e.getY() <= bottom && (((e.getX() > ((double) mOffsetHigh + mOffsetLow) / 2) && e.getX() < (mOffsetHigh - mThumbWidth / 2)) || (e .getX() > (mOffsetHigh + mThumbWidth/2) && e.getX() <= mScollBarWidth))) { return CLICK_IN_HIGH_AREA; } else if (!(e.getX() >= 0 && e.getX() <= mScollBarWidth && e.getY() >= top && e.getY() <= bottom)) { return CLICK_OUT_AREA; } else { return CLICK_INVAILD; } } //更新滑块 private void refresh() { invalidate(); } //设置前滑块的值 public void setProgressLow(double progressLow) { this.defaultScreenLow = progressLow; mOffsetLow = formatDouble(progressLow / 100 * (mDistance ))+ mThumbWidth / 2; isEdit = true; refresh(); } //设置后滑块的值 public void setProgressHigh(double progressHigh) { this.defaultScreenHigh = progressHigh; mOffsetHigh = formatDouble(progressHigh / 100 * (mDistance)) + mThumbWidth / 2; isEdit = true; refresh(); } public void setOnSeekBarChangeListener(OnSeekBarChangeListener mListener) { this.mBarChangeListener = mListener; } //回调函数，在滑动时实时调用，改变输入框的值 public interface OnSeekBarChangeListener { //滑动前 public void onProgressBefore(); //滑动时 public void onProgressChanged(SeekBarPressure seekBar, double progressLow, double progressHigh); //滑动后 public void onProgressAfter(); } /* private int formatInt(double value) { BigDecimal bd = new BigDecimal(value); BigDecimal bd1 = bd.setScale(0, BigDecimal.ROUND_HALF_UP); return bd1.intValue(); }*/ public static double formatDouble(double pDouble) { BigDecimal bd = new BigDecimal(pDouble); BigDecimal bd1 = bd.setScale(2, BigDecimal.ROUND_HALF_UP); pDouble = bd1.doubleValue(); return pDouble; } }
2、布局调用 xxx.xml
<com.xxx.SeekBarPressure android:id="@+id/seekBar_tg2" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentTop="true" android:layout_marginBottom="10dp" android:layout_marginLeft="10dp" android:layout_marginRight="10dp" />
3、在Activity中实现XxxActivity.class
seekBarPressures = (SeekBarPressure) findViewById(R.id.seekBar_tg2); seekBarPressures.setOnSeekBarChangeListener(new SeekBarPressure.OnSeekBarChangeListener() { @Override public void onProgressBefore() { isScreen = true; } @Override public void onProgressChanged(SeekBarPressure seekBar, double progressLow, double progressHigh) { editTexts_min.setText((int) progressLow + ""); editTexts_max.setText((int) progressHigh + ""); } @Override public void onProgressAfter() { isScreen = false; } });
注意：seekBar的父容器必须LinearLayout，别问我为什么，我也不知道。反正如果是Rinearlayout的话，滑动会不正常，我曹了，为这问题搞了整整3个小时
