Android View实现圆形进度条

本文实例为大家分享了Android View实现圆形进度条的具体代码，供大家参考，具体内容如下

主要涉及到下面几个方法：

// 画圆canvas.drawCircle// 画圆弧canvas.drawArc// 画文本canvas.drawText// 抗锯齿paint.setAntiAlias(true);// 设置颜色paint.setColor(getResources().getColor(mFgColor, null));

其次就是对坐标的计算，还有注意就是画圆弧的时候，起始从-90度开始才是垂直上方。效果图：

自定义View：

public class MyView extends View { // 线宽度 private static final int mStrokeWidth = 50; private int mVal = 0; private static final int mMaxVal = 200; private int mGgColor = R.color.arcbg; private int mFgColor = R.color.arcfg; public MyView(Context context) {super(context); } public MyView(Context context, @Nullable AttributeSet attrs) {super(context, attrs); } // 设置值 public void setProgressValue(int val){this.mVal = val;invalidate(); } @Override protected void onDraw(Canvas canvas) {super.onDraw(canvas);int width = getMeasuredWidth();int height = getMeasuredHeight();drawBGCircle(canvas, width, height);drawFGArc(canvas, width, height);drawText(canvas, width, height); } // 文本 private void drawText(Canvas canvas, int width, int height) {Paint paint = new Paint();paint.setAntiAlias(true);paint.setColor(getResources().getColor(mFgColor, null));paint.setTextSize(120);int percent = (int) (( mVal / (float) mMaxVal ) * 100);canvas.drawText(percent + '%', (width - paint.measureText(percent + '%')) / 2, (height + paint.measureText('%')) / 2, paint); } // 圆弧 private void drawFGArc(Canvas canvas, int width, int height) {Paint paint = new Paint();paint.setColor(getResources().getColor(mFgColor, null));paint.setStyle(Paint.Style.STROKE);paint.setStrokeWidth(mStrokeWidth);paint.setAntiAlias(true);RectF mRectF = new RectF(mStrokeWidth, mStrokeWidth, width - mStrokeWidth, height - mStrokeWidth);int sweepAngle = (int) (360 * mVal / (float) mMaxVal);canvas.drawArc(mRectF, -90, sweepAngle, false, paint); } // 底部圆形 private void drawBGCircle(Canvas canvas, int width, int height) {int r = (width - 2 * mStrokeWidth) / 2;Paint cPaint = new Paint();cPaint.setColor(getResources().getColor(mGgColor, null));cPaint.setStyle(Paint.Style.STROKE);cPaint.setStrokeWidth(mStrokeWidth);cPaint.setAntiAlias(true);canvas.drawCircle(width / 2, height / 2, r, cPaint); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);int width = getSize(widthMeasureSpec, 200);int height = getSize(heightMeasureSpec, 200);setMeasuredDimension(width, height); } private int getSize(int widthMeasureSpec, int defultSize) {int realSize = defultSize;int mode = MeasureSpec.getMode(widthMeasureSpec);int size = MeasureSpec.getSize(widthMeasureSpec);switch (mode){ case MeasureSpec.UNSPECIFIED:realSize = defultSize;break; case MeasureSpec.AT_MOST:realSize = size;break; case MeasureSpec.EXACTLY:realSize = size;break;}return realSize; }}

然后在布局文件中引用：

<com.weizu.myapplication.view.MyViewandroid: android:layout_width='150dp'android:layout_height='150dp'app:layout_constraintBottom_toBottomOf='parent'app:layout_constraintEnd_toEndOf='parent'app:layout_constraintStart_toStartOf='parent'app:layout_constraintTop_toTopOf='parent' />

最后，我们设置其点击效果，并开始耗时操作模拟：

MyView view = findViewById(R.id.myView);view.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) {new Thread(new Runnable() { @Override public void run() {int val = 0;while(val <= 200){ view.setProgressValue(val); val++; try {Thread.sleep(20); } catch (InterruptedException e) {e.printStackTrace(); }} }}).start(); }});

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持好吧啦网。