由于項目需要做出此效果，自定義寫了一個。
效果圖
思路：
原始的seekbar只有滑動條并沒有下方的提示文字，所以我們必須要繼承Seekbar重寫這個控件。
代碼：
在values文件夾下新建attrs.xml,用于設置跟隨滑動按鈕的文字大小，顏色，背景。
<declare-styleable name="MySeekBar"> <attr name="textsize" format="dimension" /> <attr name="textcolor" format="color" /> <attr name="img" format="reference" /></declare-styleable>1234512345在布局里引用此控件
<com.jzh.myseekbar.MySeekBar android:id="@+id/seekBar" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_weight="1" android:max="80" android:maxHeight="10dp" android:PRogress="0" android:progressDrawable="@drawable/seekbar_style" android:splitTrack="false" android:thumb="@mipmap/niu" app:img="@mipmap/ann" app:textcolor="#fff" app:textsize="14dp" />12345678910111213141234567891011121314自定義控件樣式
<?xml version="1.0" encoding="utf-8"?><layer-list xmlns:android="http://schemas.android.com/apk/res/android"> <item android:id="@android:id/background"> <shape> <corners android:radius="5dp" /> <gradient android:angle="0" android:centerColor="@android:color/holo_orange_dark" android:endColor="@android:color/holo_red_dark" android:startColor="#2aade3" /> </shape> </item></layer-list>12345678910111213141516171234567891011121314151617主要核心代碼
/** * 文本的顏色 */ private int mTitleTextColor; /** * 文本的大小 */ private float mTitleTextSize; private String mTitleText;//文字的內容 /** * 背景圖片 */ private int img; private Bitmap map; //bitmap對應的寬高 private float img_width, img_height; Paint paint; private float numTextWidth; //測量seekbar的規格 private Rect rect_seek; private Paint.FontMetrics fm; public static final int TEXT_ALIGN_LEFT = 0x00000001; public static final int TEXT_ALIGN_RIGHT = 0x00000010; public static final int TEXT_ALIGN_CENTER_VERTICAL = 0x00000100; public static final int TEXT_ALIGN_CENTER_HORIZONTAL = 0x00001000; public static final int TEXT_ALIGN_TOP = 0x00010000; public static final int TEXT_ALIGN_BOTTOM = 0x00100000; /** * 文本中軸線X坐標 */ private float textCenterX; /** * 文本baseline線Y坐標 */ private float textBaselineY; /** * 文字的方位 */ private int textAlign; public MySeekBar(Context context) { this(context, null); } public MySeekBar(Context context, AttributeSet attrs) { this(context, attrs, 0); } public MySeekBar(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); TypedArray array = context.getTheme().obtainStyledAttributes(attrs, R.styleable.MySeekBar, defStyleAttr, 0); int n = array.getIndexCount(); for (int i = 0; i < n; i++) { int attr = array.getIndex(i); switch (attr) { case R.styleable.MySeekBar_textsize: mTitleTextSize = array.getDimension(attr, 15f); break; case R.styleable.MySeekBar_textcolor: mTitleTextColor = array.getColor(attr, Color.WHITE); break; case R.styleable.MySeekBar_img: img = array.getResourceId(attr, R.mipmap.ic_launcher); break; } } array.recycle(); getImgWH(); paint = new Paint(); paint.setAntiAlias(true);//設置抗鋸齒 paint.setTextSize(mTitleTextSize);//設置文字大小 paint.setColor(mTitleTextColor);//設置文字顏色 //設置控件的padding 給提示文字留出位置 setPadding((int) Math.ceil(img_width) / 2, 0, (int) Math.ceil(img_height) / 2, (int) Math.ceil(img_height) + 10); textAlign = TEXT_ALIGN_CENTER_HORIZONTAL | TEXT_ALIGN_CENTER_VERTICAL; } /** * 獲取圖片的寬高 */ private void getImgWH() { map = BitmapFactory.decodeResource(getResources(), img); img_width = map.getWidth(); img_height = map.getHeight(); } @Override protected synchronized void onDraw(Canvas canvas) { super.onDraw(canvas); setTextLocation();//定位文本繪制的位置 rect_seek = this.getProgressDrawable().getBounds(); //定位文字背景圖片的位置 float bm_x = rect_seek.width() * getProgress() / getMax(); float bm_y = rect_seek.height() + 20;// //計算文字的中心位置在bitmap float text_x = rect_seek.width() * getProgress() / getMax() + (img_width - numTextWidth) / 2; canvas.drawBitmap(map, bm_x, bm_y, paint);//畫背景圖 // canvas.drawRoundRect(); canvas.drawText(mTitleText, text_x, (float) (textBaselineY + bm_y + (0.16 * img_height / 2)), paint);//畫文字 } @Override public boolean onTouchEvent(MotionEvent event) { invalidate();//監聽手勢滑動，不斷重繪文字和背景圖的顯示位置 return super.onTouchEvent(event); } /** * 定位文本繪制的位置 */ private void setTextLocation() { fm = paint.getFontMetrics(); //文本的寬度 mTitleText = getProgress() + 10 + "℃"; numTextWidth = paint.measureText(mTitleText); float textCenterVerticalBaselineY = img_height / 2 - fm.descent + (fm.descent - fm.ascent) / 2; switch (textAlign) { case TEXT_ALIGN_CENTER_HORIZONTAL | TEXT_ALIGN_CENTER_VERTICAL: textCenterX = img_width / 2; textBaselineY = textCenterVerticalBaselineY; break; case TEXT_ALIGN_LEFT | TEXT_ALIGN_CENTER_VERTICAL: textCenterX = numTextWidth / 2; textBaselineY = textCenterVerticalBaselineY; break; case TEXT_ALIGN_RIGHT | TEXT_ALIGN_CENTER_VERTICAL: textCenterX = img_width - numTextWidth / 2; textBaselineY = textCenterVerticalBaselineY; break; case TEXT_ALIGN_BOTTOM | TEXT_ALIGN_CENTER_HORIZONTAL: textCenterX = img_width / 2; textBaselineY = img_height - fm.bottom; break; case TEXT_ALIGN_TOP | TEXT_ALIGN_CENTER_HORIZONTAL: textCenterX = img_width / 2; textBaselineY = -fm.ascent; break; case TEXT_ALIGN_TOP | TEXT_ALIGN_LEFT: textCenterX = numTextWidth / 2; textBaselineY = -fm.ascent; break; case TEXT_ALIGN_BOTTOM | TEXT_ALIGN_LEFT: textCenterX = numTextWidth / 2; textBaselineY = img_height - fm.bottom; break; case TEXT_ALIGN_TOP | TEXT_ALIGN_RIGHT: textCenterX = img_width - numTextWidth / 2; textBaselineY = -fm.ascent; break; case TEXT_ALIGN_BOTTOM | TEXT_ALIGN_RIGHT: textCenterX = img_width - numTextWidth / 2; textBaselineY = img_height - fm.bottom; break; } }
