Android自定義View制作儀表盤界面

2019-12-12 04:48:22

字體：大中小

來源：轉載

供稿：網友

前言

最近我跟自定義View杠上了，甚至說有點上癮到走火入魔了。身為菜鳥的我自然要查閱大量的資料，學習大神們的代碼，這不，前兩天正好在郭神在微信公眾號里推送一片自定義控件的文章――一步步實現精美的鐘表界面。正適合我這種菜鳥來學習，閑著沒事，我就差不多依葫蘆畫瓢也寫了一個自定義表盤View，現在純粹最為筆記記錄下來。先展示下效果圖：

下面進入正題

自定義表盤屬性

老規矩，先在attrs文件里添加表盤自定義屬性

<declare-styleable name="WatchView"> <attr name="watchRadius" format="dimension"/> //表盤半徑 <attr name="watchPadding" format="dimension"/> //表盤相對控件邊框距離 <attr name="watchScalePadding" format="dimension"/> //刻度相對表盤距離 <attr name="watchScaleColor" format="color|reference"/> //常規刻度顏色 <attr name="watchScaleLength" format="dimension|reference"/> //常規刻度長度 <attr name="watchHourScaleColor" format="dimension|reference"/> //整點刻度顏色 <attr name="watchHourScaleLength" format="dimension|reference"/> //整點刻度長度 <attr name="hourPointColor" format="color|reference"/> //時針顏色 <attr name="hourPointLength" format="dimension|reference"/> //時針長度 <attr name="minutePointColor" format="color|reference"/> //分針顏色 <attr name="minutePointLength" format="dimension|reference"/> //分針長度 <attr name="secondPointColor" format="color|reference"/> //秒針顏色 <attr name="secondPointLength" format="dimension|reference"/> //秒針長度 <attr name="timeTextSize" format="dimension|reference"/> //表盤字體大小 <attr name="timeTextColor" format="color|reference"/> //表盤字體顏色 </declare-styleable>

在自定義View的構造方法種獲取自定義屬性

先將屬性變量聲明如下：

<span style="font-size:14px;"> /**表盤邊距*/ private float mWatchPadding = 5; /**表盤與刻度邊距*/ private float mWatchScalePadding = 5; /**表盤半徑*/ private float mWatchRadius = 250; /**表盤刻度長度*/ private float mWatchScaleLength; /**表盤刻度顏色*/ private int mWatchScaleColor = Color.BLACK; /**表盤整點刻度長度*/ private float mHourScaleLength = 8; /**表盤整點刻度顏色*/ private int mHourScaleColor = Color.BLUE; /**表盤時針顏色*/ private int mHourPointColor = Color.BLACK; /**表盤時針長度*/ private float mHourPointLength = 100; /**表盤分針顏色*/ private int mMinutePointColor = Color.BLACK; /**表盤分針長度*/ private float mMinutePointLength = 130; /**表盤秒針顏色*/ private int mSecondPointColor = Color.RED; /**表盤秒針長度*/ private float mSecondPointLength = 160; /**表盤尾部指針長度*/ private float mEndPointLength; /**表盤數字顏色*/ private int mTimeTextColor = Color.BLACK; /**表盤數字大小*/ private int mTimeTextSize = 15;</span>

在構造方法種獲取自定義屬性

<span style="font-size:14px;"> public WatchView(Context context, AttributeSet attrs) { super(context, attrs); TypedArray array = context.obtainStyledAttributes(attrs,R.styleable.WatchView); int n = array.getIndexCount(); for (int i = 0;i<n;i++){ int attr = array.getIndex(i); switch (attr){ case R.styleable.WatchView_watchRadius: mWatchRadius = array.getDimensionPixelSize(attr,MyUtil.dip2px(context,60)); break; case R.styleable.WatchView_watchPadding: mWatchPadding = array.getDimensionPixelSize(attr,MyUtil.dip2px(context,5)); break; case R.styleable.WatchView_watchScalePadding: mWatchScalePadding = array.getDimensionPixelSize(attr,MyUtil.dip2px(context,3)); break; case R.styleable.WatchView_watchScaleLength: mWatchScaleLength = array.getDimensionPixelSize(attr,MyUtil.dip2px(context,5)); break; case R.styleable.WatchView_watchScaleColor: mWatchScaleColor = array.getColor(attr, Color.parseColor("#50000000")); break; case R.styleable.WatchView_watchHourScaleLength: mHourScaleLength = array.getDimensionPixelSize(attr,MyUtil.dip2px(context,10)); break; case R.styleable.WatchView_watchHourScaleColor: mHourScaleColor = array.getColor(attr,Color.BLACK); break; case R.styleable.WatchView_hourPointLength: mHourPointLength = array.getDimensionPixelSize(attr,MyUtil.dip2px(context,35)); break; case R.styleable.WatchView_hourPointColor: mHourPointColor = array.getColor(attr,Color.BLACK); break; case R.styleable.WatchView_minutePointLength: mMinutePointLength = array.getDimensionPixelSize(attr,MyUtil.dip2px(context,40)); break; case R.styleable.WatchView_minutePointColor: mMinutePointColor = array.getColor(attr,Color.BLACK); break; case R.styleable.WatchView_secondPointLength: mSecondPointLength = array.getDimensionPixelSize(attr,MyUtil.dip2px(context,50)); break; case R.styleable.WatchView_secondPointColor: mSecondPointColor = array.getColor(attr,Color.BLUE); break; case R.styleable.WatchView_timeTextSize: mTimeTextSize = array.getDimensionPixelSize(attr,MyUtil.dip2px(context,15)); break; case R.styleable.WatchView_timeTextColor: mTimeTextColor = array.getColor(attr,Color.BLACK); break; } } array.recycle(); }</span>

設置控件大小

這里當然就是重寫onMeasure方法啦，這里我們處理的簡單點，如下面代碼所示，當我們將控件的寬高都設定為wrap_content（即MeasureSpec.UNSPECIFED）時，我們將寬高設定為默認值（wrapContentSize）和圓盤半徑+圓盤邊距（mWatchRadius+mWatchPadding）之間取最大值，其他情況下就取系統自取值。當然作為一個嚴謹的控件，僅僅這樣處理肯定是不行的。項目中，我們要根據我們的需求自行修改里面的代碼以適配。

<span style="font-size:14px;"> @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { int wrapContentSize = 1000; int widthSize = MeasureSpec.getSize(widthMeasureSpec); int widthMode = MeasureSpec.getMode(widthMeasureSpec); int heightSize = MeasureSpec.getSize(heightMeasureSpec); int heightMode = MeasureSpec.getMode(heightMeasureSpec); if (widthMode == MeasureSpec.UNSPECIFIED && heightMode == MeasureSpec.UNSPECIFIED){ wrapContentSize = (int) Math.max(wrapContentSize,mWatchRadius+mWatchPadding); setMeasuredDimension(wrapContentSize,wrapContentSize); }else { setMeasuredDimension(widthSize,heightSize); } }</span>

重寫onDraw方法

來到最關鍵真正畫表盤時刻了。一步一步來，首先初始化我們的畫筆（我的習慣，寫一個initPaint方法）

<span style="font-size:14px;"> private void initPaint(){ mPaint = new Paint(); mPaint.setAntiAlias(true); mPaint.setColor(Color.WHITE); mPaint.setStyle(Paint.Style.FILL); }</span>

為了不顯贅述，方便理解，我直接展示代碼，在代碼中解釋

開畫之前我們先將畫筆移動到控件中心點位置，如下：

<span style="font-size:14px;">@Override protected void onDraw(Canvas canvas) { canvas.translate(getWidth()/2,getHeight()/2); }</span>

第一步，畫表盤

<span style="font-size:14px;"> /** * 畫表盤 * @param canvas */ private void paintWatchBoard(Canvas canvas){ initPaint(); canvas.save(); canvas.drawCircle(0,0,mWatchRadius,mPaint); //畫圓盤 canvas.restore(); }</span>

注：每次畫圖之前都要先調用canvas.save()方法，保存畫筆屬性，畫完之后要調用canvas.restore()方法，重置畫筆屬性

這里就不一一展示每次畫完之后的效果圖了。

第二步，畫刻度+整點時間數字（刻度從12點方向開始畫）

<span style="font-size:14px;"> /** * 畫刻度及整點數字 * @param canvas */ private void paintScale(Canvas canvas){ int lineLength; //刻度線長度 canvas.save(); for (int i = 0;i<60;i++){ if (i%5 == 0){//整點刻度下畫筆相關屬性 mPaint.setStrokeWidth(MyUtil.dip2px(getContext(),1.5f)); mPaint.setColor(mHourScaleColor); lineLength = MyUtil.dip2px(getContext(),8); canvas.drawLine(0,-mWatchRadius+mWatchScalePadding,0,-mWatchRadius+mWatchScalePadding+lineLength,mPaint); mPaint.setColor(mTimeTextColor); mPaint.setTextSize(mTimeTextSize); canvas.drawText(mTimes[i/5],-mTimeTextSize/2,-mWatchRadius+mWatchScalePadding + lineLength+mTimeTextSize,mPaint);//整點的位置標上整點時間數字 }else {//非整點刻度下畫筆相關屬性 mPaint.setStrokeWidth(MyUtil.dip2px(getContext(),0.8f)); mPaint.setColor(mWatchScaleColor); lineLength = MyUtil.dip2px(getContext(),5); canvas.drawLine(0,-mWatchRadius+mWatchScalePadding,0,-mWatchRadius+mWatchScalePadding+lineLength,mPaint); } canvas.rotate(6);//每次畫完一個刻度線，畫筆順時針旋轉6度（360/60，相鄰兩刻度之間的角度差為6度） } canvas.restore(); }</span>

其中，整點數字我用了羅馬數字來表示

<span style="font-size:14px;">private String[] mTimes = {"XII","Ⅰ","Ⅱ","Ⅲ","Ⅳ","Ⅴ","Ⅵ","Ⅶ","Ⅷ","Ⅸ","Ⅹ","XI"};</span>

第三步，畫時針、分針、秒針以及其它修飾圖

考慮到時針、分針和秒針大小長度各不一樣，我這里特意定義了三支畫筆來分別畫時針、分針和秒針。

同樣的，先初始化指針畫筆：

<span style="font-size:14px;">/** * 初始化指針 */ private void initPointPaint(){ mHourPaint = new Paint(); mHourPaint.setAntiAlias(true); mHourPaint.setStyle(Paint.Style.FILL); mHourPaint.setStrokeWidth(16); mHourPaint.setColor(mHourPointColor); mMinutePaint = new Paint(); mMinutePaint.set(mHourPaint); mMinutePaint.setStrokeWidth(12); mMinutePaint.setColor(mMinutePointColor); mSecondPaint = new Paint(); mSecondPaint.set(mHourPaint); mSecondPaint.setStrokeWidth(7); mSecondPaint.setColor(mSecondPointColor); mEndPointLength = mWatchRadius/6; //（修飾部分）指針尾部長度，定義為表盤半徑的六分之一 }</span>

畫指針

<span style="font-size:14px;">/** * 畫指針 * @param canvas */ private void paintPoint(Canvas canvas){ initPointPaint(); Calendar c = Calendar.getInstance(); //取當前時間 int hour = c.get(Calendar.HOUR_OF_DAY); int minute = c.get(Calendar.MINUTE); int second = c.get(Calendar.SECOND); //繪制時針 canvas.save(); canvas.rotate(hour*30); canvas.drawLine(0,0,0,-mHourPointLength,mHourPaint); canvas.drawLine(0,0,0,mEndPointLength,mHourPaint); canvas.restore(); //繪制分針 canvas.save(); canvas.rotate(minute*6); canvas.drawLine(0,0,0,-mMinutePointLength,mMinutePaint); canvas.drawLine(0,0,0,mEndPointLength,mMinutePaint); canvas.restore(); //繪制秒針 canvas.save(); canvas.rotate(second*6); canvas.drawLine(0,0,0,-mSecondPointLength,mSecondPaint); canvas.drawLine(0,0,0,mEndPointLength,mSecondPaint); canvas.restore(); }</span>

OK，該有的差不多都有了，直接在onDraw中調用吧

<span style="font-size:14px;">@Override protected void onDraw(Canvas canvas) { canvas.translate(getWidth()/2,getHeight()/2); paintWatchBoard(canvas); //畫表盤 paintScale(canvas); //畫刻度 paintPoint(canvas); //畫指針 canvas.drawCircle(0,0,15,mSecondPaint); //為了美觀，也讓表盤更接近我們顯示生活中的樣子，我在圓盤中心畫了一個大紅圓點裝飾秒針 postInvalidateDelayed(1000); //每隔一秒鐘畫一次 }</span>

(⊙v⊙)嗯，自定義View大功告成，我們在布局文件里調用看下效果吧

<span style="font-size:14px;"><?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:zhusp="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@color/colorAccent"> <com.wondertek.propertyanimatordemo.WatchView android:layout_width="wrap_content" android:layout_height="wrap_content" zhusp:timeTextSize="20dp" zhusp:watchRadius="150dp" zhusp:hourPointLength="80dp" zhusp:minutePointLength="100dp" zhusp:secondPointLength="115dp"/> </RelativeLayout></span>

最后我這里的靜態效果是這樣的：