这个是一个以弧线为依托的进度控件，主要包括了两个圆弧、一个圆、一个文本。

当我们点击开始按钮的时候，会出现一个动画，逐渐的出现进度，好了，下面开始我们的编码。

新建一个类，继承自View，实现三个构造方法，接着定义变量，初始化变量的数据。代码如下：

private Paint mArcPaint, mCirclePaint, mTextPaint, mPaint; private float length; private float mRadius; private float mCircleXY; private float mSweepValue = 0; private String mShowText = "0%"; private RectF mRectF; public MViewOne(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); initView(); } public MViewOne(Context context, AttributeSet attrs) { super(context, attrs); initView(); } public MViewOne(Context context) { super(context); initView(); } private void initView() { mArcPaint = new Paint(); mArcPaint.setStrokeWidth(50); mArcPaint.setAntiAlias(true); mArcPaint.setColor(Color.GREEN); mArcPaint.setStyle(Style.STROKE); mCirclePaint = new Paint(); mCirclePaint.setColor(Color.GREEN); mCirclePaint.setAntiAlias(true); mTextPaint = new Paint(); mTextPaint.setAntiAlias(true); mTextPaint.setColor(Color.RED); mTextPaint.setStrokeWidth(0); mPaint = new Paint(); mPaint.setStrokeWidth(40); mPaint.setAntiAlias(true); mPaint.setColor(Color.YELLOW); mPaint.setStyle(Style.STROKE); }

可以看到，这里一共定义了四个画笔，两个画弧形，一个画文本，还有一个绘制圆。

在我们的onSizeChange方法里面，再给变量赋值。

@Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); length = w; mCircleXY = length / 2; mRadius = (float) (length * 0.5 / 2); }

这时候，圆的半径、圆的起绘点，都已经有值了。

下面开始绘制

@Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); // 画圆 mRectF = new RectF((float) (length * 0.1), (float) (length * 0.1), (float) (length * 0.9), (float) (length * 0.9)); canvas.drawCircle(mCircleXY, mCircleXY, mRadius, mCirclePaint); // 画弧线 canvas.drawArc(mRectF, 270, 360, false, mPaint); canvas.drawArc(mRectF, 270, mSweepValue, false, mArcPaint); // 绘制文字 float textWidth = mTextPaint.measureText(mShowText); //测量字体宽度，我们需要根据字体的宽度设置在圆环中间 canvas.drawText(mShowText, (int)(length/2-textWidth/2), (int)(length/2+textWidth/2) , mTextPaint); }

这个时候，全部的效果已经出来了，但是这个还是静态的，对外暴露一个方法，让数据可以动态的刷新

public void setProgress(float mSweepValue) { float a = (float) mSweepValue; if (a != 0) { this.mSweepValue = (float) (360.0 * (a / 100.0)); mShowText = mSweepValue + "%"; Log.e("this.mSweepValue:", this.mSweepValue + ""); } else { this.mSweepValue = 25; mShowText = 25 + "%"; } invalidate(); }

好了，所有的代码都在这里了，老规矩，最后我贴上全部的代码：

public class MViewOne extends View { private Paint mArcPaint, mCirclePaint, mTextPaint, mPaint; private float length; private float mRadius; private float mCircleXY; private float mSweepValue = 0; private String mShowText = "0%"; private RectF mRectF; public MViewOne(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); initView(); } public MViewOne(Context context, AttributeSet attrs) { super(context, attrs); initView(); } public MViewOne(Context context) { super(context); initView(); } private void initView() { mArcPaint = new Paint(); mArcPaint.setStrokeWidth(50); mArcPaint.setAntiAlias(true); mArcPaint.setColor(Color.GREEN); mArcPaint.setStyle(Style.STROKE); mCirclePaint = new Paint(); mCirclePaint.setColor(Color.GREEN); mCirclePaint.setAntiAlias(true); mTextPaint = new Paint(); mTextPaint.setAntiAlias(true); mTextPaint.setColor(Color.RED); mTextPaint.setStrokeWidth(0); mPaint = new Paint(); mPaint.setStrokeWidth(40); mPaint.setAntiAlias(true); mPaint.setColor(Color.YELLOW); mPaint.setStyle(Style.STROKE); } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); length = w; mCircleXY = length / 2; mRadius = (float) (length * 0.5 / 2); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); // 画圆 mRectF = new RectF((float) (length * 0.1), (float) (length * 0.1), (float) (length * 0.9), (float) (length * 0.9)); canvas.drawCircle(mCircleXY, mCircleXY, mRadius, mCirclePaint); // 画弧线 canvas.drawArc(mRectF, 270, 360, false, mPaint); canvas.drawArc(mRectF, 270, mSweepValue, false, mArcPaint); // 绘制文字 float textWidth = mTextPaint.measureText(mShowText); //测量字体宽度，我们需要根据字体的宽度设置在圆环中间 canvas.drawText(mShowText, (int)(length/2-textWidth/2), (int)(length/2+textWidth/2) , mTextPaint); } public void setProgress(float mSweepValue) { float a = (float) mSweepValue; if (a != 0) { this.mSweepValue = (float) (360.0 * (a / 100.0)); mShowText = mSweepValue + "%"; Log.e("this.mSweepValue:", this.mSweepValue + ""); } else { this.mSweepValue = 25; mShowText = 25 + "%"; } invalidate(); } }

谢谢阅读，学习重在坚持，贵在坚持。

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