Android绘制圆形百分比加载圈效果

/**
 * 绘制圆
 * @param cx   圆心x坐标
 * @param cy   圆心y坐标
 * @param radius 圆的半径
 * @param paint 画笔
 */
 public void drawCircle(float cx, float cy, float radius, @NonNull Paint paint) {
 ...
 }


/**
 * 绘制圆弧
 * @param oval    决定圆弧范围的矩形区域
 * @param startAngle 开始角度
 * @param sweepAngle 绘制的角度
 * @param useCenter 是否需要连接圆心,true连接,false不连接
 * @param paint   画笔
 */
 public void drawArc(RectF oval, float startAngle, float sweepAngle, boolean useCenter,Paint paint) {
  ...
 }


 /**
  * 绘制文本
  * @param text 需要绘制的字符串
  * @param x   绘制文本起点x坐标,注意文本比较特殊,它的起点是左下角的x坐标
  * @param y   绘制文本起点y坐标,同样是左下角的y坐标
  * @param paint 画笔
  */
 public void drawText(String text, float x, float y, Paint paint) {
  ...
 }

public class CircleProgressView extends View {
private int width;//控件宽度
private int height;//控件高
private float radius;//半径
private float pointX;//圆心x坐标
private float pointY;//圆心y坐标
private int circleBackgroundColor;//背景颜色
private int circleBackgroundAlpha; //背景透明度
private int circleRingColor;//进度颜色
private int progressTextColor;//进度文本的颜色
private int progressTextSize;//进度文本的字体大小
private int circleRingWidth; //进度的宽度
private Paint mPaint;
private int progress;//进度值
private boolean isRingStyle;//是否是空心的圆环进度样式
public CircleProgressView(Context context) {
this(context, null);
}
public CircleProgressView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public CircleProgressView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
circleBackgroundColor = Color.WHITE;
circleRingColor = Color.parseColor("#3A91FF");
progressTextColor = Color.BLACK;
circleBackgroundAlpha = 128;
progressTextSize = 32;
circleRingWidth = 10;
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setStyle(Paint.Style.FILL);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
width = getMeasuredWidth();
height = getMeasuredHeight();
radius = Math.min(width, height) / 2.0f;
pointX = width / 2.0f;
pointY = height / 2.0f;
}
@Override
protected void onDraw(Canvas canvas) {
drawBackground(canvas);
drawCircleRing(canvas);
drawProgressText(canvas);
}
/**
* 绘制背景色
*
* @param canvas
*/
private void drawBackground(Canvas canvas) {
mPaint.setColor(circleBackgroundColor);
mPaint.setAlpha(circleBackgroundAlpha);
canvas.drawCircle(pointX, pointY, radius, mPaint);
}
/**
* 绘制圆环
*
* @param canvas
*/
private void drawCircleRing(Canvas canvas) {
mPaint.setColor(circleRingColor);
RectF oval = new RectF();
if (isRingStyle) {
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(circleRingWidth);
mPaint.setStrokeCap(Paint.Cap.ROUND);
//注意:定义圆环的矩形区域是需要考虑圆环的宽度
oval.left = circleRingWidth / 2.0f;
oval.top = height / 2.0f - radius + circleRingWidth / 2.0f;
oval.right = 2 * radius - circleRingWidth / 2.0f;
oval.bottom = height / 2.0f + radius - circleRingWidth / 2.0f;
canvas.drawArc(oval, 0, 360 * progress / 100, false, mPaint);
} else {
mPaint.setStyle(Paint.Style.FILL);
oval.left = 0;
oval.top = height / 2.0f - radius;
oval.right = 2 * radius;
oval.bottom = height / 2.0f + radius;
canvas.drawArc(oval, 0, 360 * progress / 100, true, mPaint);
}
}
/**
* 绘制进度文本
*
* @param canvas
*/
private void drawProgressText(Canvas canvas) {
mPaint.setColor(progressTextColor);
mPaint.setStyle(Paint.Style.FILL);
mPaint.setTextSize(progressTextSize);
Rect textBound = new Rect();
String text = progress + "%";
//获取文本的矩形区域到textBound中
mPaint.getTextBounds(text, 0, text.length(), textBound);
int textWidth = textBound.width();
int textHeight = textBound.height();
float x = pointX - textWidth / 2.0f;
float y = pointY + textHeight / 2.0f;
canvas.drawText(text, x, y, mPaint);
}
/**
* 更新进度
*
* @param progress
*/
public void setValue(int progress) {
this.progress = progress;
invalidate();
}
/**
* 设置进度圆环的样式
*
* @param isRing true是空心的圆环,false表示实心的圆环
*/
public void setCircleRingStyle(boolean isRing) {
this.isRingStyle = isRing;
}
/**
* 设置背景透明度
*
* @param alpha 0~255
*/
public void setCircleBackgroundAlpha(int alpha) {
this.circleBackgroundAlpha = alpha;
}
/**
* 设置进度文本的大小
* @param progressTextSize
*/
public void setProgressTextSize(int progressTextSize) {
this.progressTextSize = progressTextSize;
}
/**
* 设置进度文本的颜色
* @param progressTextColor
*/
public void setProgressTextColor(int progressTextColor) {
this.progressTextColor = progressTextColor;
}
}

public class MainActivity extends AppCompatActivity {
private CircleProgressView mCircleProgressView;
private int progress;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mCircleProgressView = (CircleProgressView) findViewById(R.id.progressView);
mCircleProgressView.setCircleRingStyle(false);//实心圆
HandlerThread thread = new HandlerThread("draw-thread");
thread.start();
Handler tHandler = new Handler(thread.getLooper()) {
@Override
public void handleMessage(Message msg) {
runOnUiThread(new Runnable() {
@Override
public void run() {
mCircleProgressView.setValue(progress++);
}
});
if (progress <100) {
sendEmptyMessageDelayed(0, 100);
}
}
};
tHandler.sendEmptyMessage(0);
}
}

<?xml version="1.0" encoding="utf-8"? 
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/colorAccent"
tools:context="mchenys.net.csdn.blog.progressview.MainActivity" 
<mchenys.net.csdn.blog.progressview.CircleProgressView
android:id="@+id/progressView"
android:layout_width="100dp"
android:layout_height="200dp"
android:layout_centerInParent="true"
/ 
</RelativeLayout