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這篇文章將為大家詳細講解有關如何在Android中利用View實現一個等級滑動條功能,文章內容質量較高,因此小編分享給大家做個參考,希望大家閱讀完這篇文章后對相關知識有一定的了解。
思路:
首先繪制直線,然后等分直線繪制點;
繪制點的時候把X值存到集合中。
然后繪制背景圖片,以及圖片上的數字。
點擊事件down的時候,換小圖片為大圖片。move的時候跟隨手指移動。
up的時候根據此時的X計算最近的集合中的點,然后自動吸附回去。
1,自定義屬性
<?xml version="1.0" encoding="utf-8"?> <resources> <declare-styleable name="BeautySeekBarView"> <attr name="valueCountent" format="integer"/> <attr name="padding" format="dimension"/> <attr name="pointColor" format="color"/> <attr name="lineColor" format="color"/> <attr name="smallPic" format="reference"/> <attr name="bigPic" format="reference"/> </declare-styleable> </resources>
然后獲取屬性:
/** * 獲得我們所定義的自定義樣式屬性 */ TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.BeautySeekBarView, defStyleAttr, 0); //等級數量即點的個數 valueCountent=a.getInteger(R.styleable.BeautySeekBarView_valueCountent, 5); //點的顏色 pointColor = a.getColor(R.styleable.BeautySeekBarView_pointColor, Color.WHITE); //線的顏色 lineColor = a.getColor(R.styleable.BeautySeekBarView_lineColor, Color.WHITE); //小圖片 smallPic=a.getResourceId(R.styleable.BeautySeekBarView_smallPic, R.drawable.ic_launcher); //滑動過程中的大圖片 bigPic=a.getResourceId(R.styleable.BeautySeekBarView_bigPic, R.drawable.ic_launcher); //控件的內邊距 viewPadding=a.getDimensionPixelSize(R.styleable.BeautySeekBarView_padding, (int) TypedValue.applyDimension( TypedValue.COMPLEX_UNIT_SP, 16, getResources().getDisplayMetrics())); a.recycle();
2.繪制
@Override protected void onDraw(Canvas canvas) { // TODO Auto-generated method stub super.onDraw(canvas); float PointX = 0; float PointY=getHeight()/2; canvas.drawLine(0+getPaddingLeft(),PointY, getWidth()-getPaddingRight(), PointY, linePaint); //繪制直線 int averageLength =(getWidth()-getPaddingLeft()-getPaddingRight())/(valueCountent-1); for(int i=0;i<valueCountent;i++){ PointX=i*averageLength+getPaddingLeft(); canvas.drawPoint(PointX, PointY, pointPaint);//繪制點 if(pointList!=null && pointList.size()<valueCountent){ pointList.add(PointX);//把每個點都放入集合中; } } sePoolTH.release(); canvas.drawBitmap(mBitmap, bitmapPointX-bitmapWidth/2, PointY-bitmapHeight/2, null);//繪制拖動的圖片 canvas.drawText(""+index, bitmapPointX, (getHeight() - fontMetrics.ascent - fontMetrics.descent) / 2, textPaint); //繪制文字 }
全部代碼如下
import java.util.ArrayList; import java.util.HashMap; import java.util.concurrent.Semaphore; import android.R.integer; import android.animation.ValueAnimator; import android.content.Context; import android.content.res.TypedArray; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Paint.FontMetricsInt; import android.util.AttributeSet; import android.util.Log; import android.util.TypedValue; import android.view.MotionEvent; import android.view.View; public class BeautySeekBarView extends View { private Semaphore sePoolTH=new Semaphore(0);//信號量,解決并發問題 private int valueCountent;//等級點的數量 private int pointColor; private int lineColor; private Bitmap mBitmap; private int bitmapWidth; private int bitmapHeight; private float bitmapPointX; private ArrayList<Float> pointList;//儲存畫出的點的point值 private HashMap<Float, Float> mHashMap;////把差值和listX當做鍵值對保存起來,便于后期找出 private int index=1;//索引 private float mListX;//移動后最小的點 private int smallPic; private int bigPic; private int viewPadding; private Paint pointPaint; private Paint linePaint; private Paint textPaint; private FontMetricsInt fontMetrics; public BeautySeekBarView(Context context) { this(context,null); } public BeautySeekBarView(Context context, AttributeSet attrs) { this(context, attrs,0); } public BeautySeekBarView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); /** * 獲得我們所定義的自定義樣式屬性 */ TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.BeautySeekBarView, defStyleAttr, 0); //等級數量即點的個數 valueCountent=a.getInteger(R.styleable.BeautySeekBarView_valueCountent, 5); //點的顏色 pointColor = a.getColor(R.styleable.BeautySeekBarView_pointColor, Color.WHITE); //線的顏色 lineColor = a.getColor(R.styleable.BeautySeekBarView_lineColor, Color.WHITE); //小圖片 smallPic=a.getResourceId(R.styleable.BeautySeekBarView_smallPic, R.drawable.ic_launcher); //滑動過程中的大圖片 bigPic=a.getResourceId(R.styleable.BeautySeekBarView_bigPic, R.drawable.ic_launcher); //控件的內邊距 viewPadding=a.getDimensionPixelSize(R.styleable.BeautySeekBarView_padding, (int) TypedValue.applyDimension( TypedValue.COMPLEX_UNIT_SP, 16, getResources().getDisplayMetrics())); a.recycle(); initData();//初始化數據 initPaint();//初始化畫筆 } public void initData() { // valueCountent=7; // pointColor=Color.WHITE; // lineColor=Color.WHITE; // setBackgroundColor(Color.BLACK); setPadding(viewPadding, viewPadding, viewPadding, viewPadding); bitmapPointX=getPaddingLeft(); mBitmap=BitmapFactory.decodeResource(getResources(), smallPic); bitmapWidth=mBitmap.getWidth(); bitmapHeight=mBitmap.getHeight(); pointList=new ArrayList<Float>(); mHashMap=new HashMap<Float, Float>(); } public void initPaint() { pointPaint=new Paint(); pointPaint.setColor(pointColor); pointPaint.setStyle(Paint.Style.FILL); pointPaint.setStrokeWidth(10); pointPaint.setStrokeJoin(Paint.Join.ROUND); pointPaint.setStrokeCap(Paint.Cap.ROUND); pointPaint.setAntiAlias(true); linePaint=new Paint(); linePaint.setColor(lineColor); linePaint.setStyle(Paint.Style.STROKE); linePaint.setStrokeWidth(4); linePaint.setAntiAlias(true); textPaint=new Paint(); textPaint.setStrokeWidth(3); textPaint.setTextSize(24); textPaint.setColor(Color.WHITE); textPaint.setTextAlign(Paint.Align.CENTER); fontMetrics = textPaint.getFontMetricsInt(); textPaint.setAntiAlias(true); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { // TODO Auto-generated method stub super.onMeasure(widthMeasureSpec, heightMeasureSpec); } @Override protected void onDraw(Canvas canvas) { // TODO Auto-generated method stub super.onDraw(canvas); float PointX = 0; float PointY=getHeight()/2; canvas.drawLine(0+getPaddingLeft(),PointY, getWidth()-getPaddingRight(), PointY, linePaint); //繪制直線 int averageLength =(getWidth()-getPaddingLeft()-getPaddingRight())/(valueCountent-1); for(int i=0;i<valueCountent;i++){ PointX=i*averageLength+getPaddingLeft(); canvas.drawPoint(PointX, PointY, pointPaint);//繪制點 if(pointList!=null && pointList.size()<valueCountent){ pointList.add(PointX);//把每個點都放入集合中; } } sePoolTH.release(); canvas.drawBitmap(mBitmap, bitmapPointX-bitmapWidth/2, PointY-bitmapHeight/2, null);//繪制拖動的圖片 canvas.drawText(""+index, bitmapPointX, (getHeight() - fontMetrics.ascent - fontMetrics.descent) / 2, textPaint); //繪制文字 } long startTime = 0; @Override public boolean onTouchEvent(MotionEvent event) { //獲取手指的操作--》按下、移動、松開 int action = event.getAction(); switch (action) { case MotionEvent.ACTION_DOWN: startTime=System.currentTimeMillis(); mBitmap=BitmapFactory.decodeResource(getResources(), bigPic); bitmapWidth=mBitmap.getWidth(); bitmapHeight=mBitmap.getHeight(); textPaint.setTextSize(30); //invalidate(); break; case MotionEvent.ACTION_MOVE: long endTimeMove=System.currentTimeMillis(); if(endTimeMove-startTime>100){//如果按下,抬起時間過大才認為是拖動,要執行動畫。 bitmapPointX=event.getX(); updateIndex(bitmapPointX); invalidate(); } break; case MotionEvent.ACTION_UP: long endTime=System.currentTimeMillis(); bitmapPointX=event.getX(); mBitmap=BitmapFactory.decodeResource(getResources(),smallPic); bitmapWidth=mBitmap.getWidth(); bitmapHeight=mBitmap.getHeight(); textPaint.setTextSize(24); if(endTime-startTime>200){//如果按下,抬起時間過大才認為是拖動,要執行動畫。 updateBitmapUI(bitmapPointX); }else{ bitmapPointX=updateIndex(bitmapPointX); invalidate(); } startTime = 0; break; } return true; } //更新索引 public float updateIndex(float pointX){ float lastValue=100000; float currentValue=0; float minValue=0; for(float listX:pointList){ currentValue= Math.abs(pointX-listX); mHashMap.put(currentValue, listX);//把差值和listX當做鍵值對保存起來,便于后期找出 minValue=Math.min(lastValue,currentValue); lastValue=minValue; } if(mHashMap.containsKey(minValue)){ mListX=mHashMap.get(minValue); }else{ Log.e("BeautySeekBarView", "updateBitmapUI--->mHashMap.containsKey(minValue) is null"); return -1; } if(pointList.contains(mListX)){ index=pointList.indexOf(mListX)+1; if(mListener!=null){ mListener.getIndex(index); } }else{ Log.e("BeautySeekBarView", "updateBitmapUI--->pointList.contains(mListX) is null"); return -1; } return mListX; } //當手指抬起后更新Bitmap的位置 private void updateBitmapUI(float PointX2) { mListX=updateIndex(PointX2); //執行動畫 ValueAnimator anim = ValueAnimator.ofFloat(PointX2, mListX); anim.setDuration(50); anim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { bitmapPointX =(Float) animation.getAnimatedValue(); invalidate(); } }); anim.start(); } //設置等級點的數量 public void pointValueCountent(int countent){ if(countent<2){ valueCountent=2; }else{ valueCountent=countent; } invalidate(); } //設置默認位置 public void setPointLocation(final int location){ new Thread(new Runnable() { @Override public void run() { try { sePoolTH.acquire(); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } if(location>0&&pointList!=null&& !pointList.isEmpty()){ bitmapPointX=pointList.get(location-1); postInvalidate(); } } }).start(); } //提供接口回調,獲取索引 private indexListener mListener=null; public interface indexListener{ void getIndex(int index); } public void setIndexListener(indexListener listener){ mListener=listener; } }
外部調用:
XML:
<com.example.hello.BeautySeekBarView android:id="@+id/myView" android:layout_centerVertical="true" android:layout_width="match_parent" android:layout_height="100dp" ws:padding="20dp" ws:valueCountent="6" ws:pointColor="#FFFFFF" ws:lineColor="#FFFFFF" ws:smallPic="@drawable/beauty_seekbar_point" ws:bigPic="@drawable/beauty_seekbar_point_big"/>
Java:
@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initView(); beautySeekBarView.setPointLocation(2) ; // } private void initView() { mTextView=(TextView) findViewById(R.id.tv); beautySeekBarView=(BeautySeekBarView) findViewById(R.id.myView); beautySeekBarView.setIndexListener(new indexListener() { @Override public void getIndex(int index) { mTextView.setText("index="+index); } }); }
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