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>