Android自定义View弧线进度控件

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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