Android custom gradient ring progress bar, android gradient Ring

Android custom gradient ring progress bar, android gradient Ring

First look at the effect:

 

Analysis: common in scenarios such as scan results and progress bars

Draw an arc using canvas. drawArc (RectF oval, float startAngle, float sweepAngle, boolean useCenter, Paint)

Some attributes of Paint define the width, color, style, etc.

LinearGradient implements linear gradient of colors

In the same way, you can draw a long progress bar, a fan chart, and so on. If you are interested, try again ..

Package com. liujing. progressviewdemo;/***** custom arc progress bar ** @ author liujing */public class ProgressView extends View {// segment Color private static final int [] SECTION_COLORS = {Color. GREEN, Color. YELLOW, Color. RED}; private static final String [] ALARM_LEVEL = {"security", "low", "medium", "high"}; private float maxCount; private float currentCount; private int score; private String crw.level; private Paint mPaint; Private Paint mTextPaint; private int mWidth, mHeight; public ProgressView (Context context, AttributeSet attrs, int defStyleAttr) {super (context, attrs, defStyleAttr); init (context );} public ProgressView (Context context, AttributeSet attrs) {this (context, attrs, 0);} public ProgressView (Context context) {this (context, null );} private void init (Context context) {mPaint = new Paint (); mTextP Aint = new Paint () ;}@ Override protected void onDraw (Canvas canvas) {super. onDraw (canvas); initPaint (); RectF rectBlackBg = new RectF (20, 20, mWidth-20, mHeight-20); canvas. drawArc (rectBlackBg, 0,360, false, mPaint); mPaint. setColor (Color. BLACK); canvas. drawText (score + "score", mWidth/2, mHeight/2, mTextPaint); mTextPaint. setTextSize (40); if (cr1_level! = Null) {canvas. drawText (cr1_level, mWidth/2, mHeight/2 + 50, mTextPaint);} float section = currentCount/maxCount; if (section <= 1.0f/3.0f) {if (section! = 0.0f) {mPaint. setColor (SECTION_COLORS [0]);} else {mPaint. setColor (Color. TRANSPARENT) ;}} else {int count = (section <= 1.0f/3.0f * 2 )? 2: 3; int [] colors = new int [count]; System. arraycopy (SECTION_COLORS, 0, colors, 0, count); float [] positions = new float [count]; if (count = 2) {positions [0] = 0.0f; positions [1] = 1.0f-positions [0];} else {positions [0] = 0.0f; positions [1] = (maxCount/3)/currentCount; positions [2] = 1.0f-positions [0] * 2;} positions [positions. length-1] = 1.0f; LinearGradient shader = new LinearGr Adient (3, 3, (mWidth-3) * section, mHeight-3, colors, null, Shader. tileMode. MIRROR); mPaint. setShader (shader);} canvas. drawArc (rectBlackBg, 180, section * 360, false, mPaint);} private void initPaint () {mPaint. setAntiAlias (true); mPaint. setStrokeWidth (float) 40.0); mPaint. setStyle (Style. STROKE); mPaint. setStrokeCap (Cap. ROUND); mPaint. setColor (Color. TRANSPARENT); mTextPaint. setAntiAlias (tru E); mTextPaint. setStrokeWidth (float) 3.0); mTextPaint. setTextAlign (Paint. align. CENTER); mTextPaint. setTextSize (50); mTextPaint. setColor (Color. BLACK);} private int dipToPx (int dip) {float scale = getContext (). getResources (). getDisplayMetrics (). density; return (int) (dip * scale + 0.5f * (dip> = 0? 1:-1);} public int getScore () {return score;} public String getCrrentLevel () {return crrentLevel;} public void setCrrentLevel (String crrentLevel) {this. crw.level = crw.level;} public float getMaxCount () {return maxCount;} public float getCurrentCount () {return currentCount;} public void setScore (int score) {this. score = score; if (score = 100) {this. crw.level = ALARM_LEVEL [0 ];} Else if (score >=70 & score <100) {this. crrentLevel = ALARM_LEVEL [1];} else if (score >=30 & score <70) {this. crw.level = ALARM_LEVEL [2];} else {this. crrentLevel = ALARM_LEVEL [3];} invalidate ();}/***** set the maximum progress value ** @ param maxCount */public void setMaxCount (float maxCount) {this. maxCount = maxCount;}/***** set the current progress value ** @ param currentCount */public void setCurrentCount (floa T currentCount) {this. currentCount = currentCount> maxCount? MaxCount: currentCount; invalidate () ;}@ Override protected void onMeasure (int widthMeasureSpec, int heightMeasureSpec) {int widthSpecMode = MeasureSpec. getMode (widthMeasureSpec); int widthSpecSize = MeasureSpec. getSize (widthMeasureSpec); int heightSpecMode = MeasureSpec. getMode (heightMeasureSpec); int heightSpecSize = MeasureSpec. getSize (heightMeasureSpec); if (widthSpecMode = MeasureSpec. EXACTLY | widthSpecMode = MeasureSpec. AT_MOST) {mWidth = widthSpecSize;} else {mWidth = 0;} if (heightSpecMode = MeasureSpec. AT_MOST | heightSpecMode = MeasureSpec. UNSPECIFIED) {mHeight = dipToPx (15);} else {mHeight = heightSpecSize;} setMeasuredDimension (mWidth, mHeight );}}

Demo: http://files.cnblogs.com/files/liujingg/ProgressViewDemo.rar