自定义View实现Android圆形进度条，viewandroid,通过继承Android的

自定义View实现Android圆形进度条，viewandroid,通过继承Android的

通过继承Android的View类，重写onDraw方法。```java import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.FontMetrics;
import android.graphics.Paint.Style;
import android.graphics.RectF;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.View;
import android.widget.ImageView;
import android.widget.SeekBar;

public class CycleView extends View {    Paint mPaint;      int progress = 30;      int start_degree = -90;    public CycleView(Context context, AttributeSet attrs) {          super(context, attrs);          InitResources(context, attrs);    }    int background_int;      int progress_int;      float layout_width_float;      int textColor_int;      float textSize_float;      int max_int;      Drawable thumb_double;      int thumbSize_int;    private void InitResources(Context context, AttributeSet attrs) {          TypedArray mTypedArray = context.obtainStyledAttributes(attrs, R.styleable.windows);        background_int = mTypedArray.getColor(R.styleable.windows_background, 0xFF87cfe8);          progress_int = mTypedArray.getColor(R.styleable.windows_progressDrawable, 0xFFabd800);          layout_width_float = mTypedArray.getDimension(R.styleable.windows_layout_width, 7);          textColor_int = mTypedArray.getColor(R.styleable.windows_textColor, 0xFFada1de);          textSize_float = mTypedArray.getDimension(R.styleable.windows_textSize, 50);          max_int = mTypedArray.getInt(R.styleable.windows_max, 100);          progress = mTypedArray.getInt(R.styleable.windows_progress, 20);          thumb_double = mTypedArray.getDrawable(R.styleable.windows_thumb);          thumbSize_int = mTypedArray.getInt(R.styleable.windows_thumbSize, 30);          mTypedArray.recycle();        if (thumb_double == null) {              Bitmap bitmap = Bitmap.createBitmap(thumbSize_int, thumbSize_int, Bitmap.Config.ARGB_8888);              // 图片画片              Canvas cas = new Canvas(bitmap);              Paint paint = new Paint();              paint.setStyle(Style.FILL);              paint.setColor(0xFF68ba32);              int center = thumbSize_int / 2;              int radius = center - 4;              cas.drawCircle(center, center, radius, paint);              thumb_double = new BitmapDrawable(getResources(), bitmap);          }        mPaint = new Paint();      }    @Override      protected void onDraw(Canvas canvas) {          super.onDraw(canvas);          drawProgressView(canvas);      }    private void drawProgressView(Canvas canvas) {          InitOval(canvas);          drawBackground(canvas);          drawProgress(canvas);          drawProgressText(canvas);      }    RectF oval;    private void InitOval(Canvas canvas) {          int center = getWidth() / 2;          int radius = (int) (center  - thumbSize_int / 2);          // 画布中央减去半径就是左上角          int left_top = center - radius;          // 画布中央加上半径就是右下角          int right_bottom = center + radius;        if (oval == null) {              oval = new RectF(left_top, left_top, right_bottom, right_bottom);          }      }    /**      * 绘制进度文字      *       * @param canvas      */      private void drawProgressText(Canvas canvas) {        mPaint.setTextSize(textSize_float);          mPaint.setColor(textColor_int);          mPaint.setStrokeWidth(2);          mPaint.setStyle(Style.FILL);          String progresstext = progress + "%";          float text_left = (getWidth() - mPaint.measureText(progresstext)) / 2;          FontMetrics fontMetrics = mPaint.getFontMetrics();          // 绘制文字是底部对齐          float text_top = (float) ((getHeight() / 2 + Math.ceil(fontMetrics.descent - fontMetrics.ascent) / 2));          canvas.drawText(progresstext, text_left, text_top, mPaint);      }    private void drawProgress(Canvas canvas) {          // 设置进度          mPaint.setColor(progress_int);          mPaint.setStrokeWidth(layout_width_float);          float seek = 0;          if (max_int > 0) {              seek = (float) progress / max_int * 360;          }          canvas.drawArc(oval, start_degree, seek, false, mPaint);        canvas.save();          int center = getWidth() / 2;          int radius = (int) (center - thumbSize_int / 2);        double cycle_round = (seek + start_degree) * Math.PI / 180;          float x = (float) (Math.cos(cycle_round) * (radius) + center - thumbSize_int / 2);          float y = (float) (Math.sin(cycle_round) * (radius) + center - thumbSize_int / 2);          thumb_double.setBounds(0, 0, thumbSize_int, thumbSize_int);          canvas.translate(x, y);          thumb_double.draw(canvas);          canvas.restore();      }    private void drawBackground(Canvas canvas) {        mPaint.setStrokeWidth(layout_width_float);          mPaint.setStyle(Paint.Style.STROKE);          mPaint.setAntiAlias(true);          // 设置背景          mPaint.setColor(background_int);          canvas.drawArc(oval, start_degree, 360, false, mPaint);    }    /**      * 查看Seekbar源码      *       * @param progress      */      public synchronized void setProgress(int progress) {          if (progress > max_int) {              progress = max_int;          }          this.progress = progress;          postInvalidate();      }    public int getProgress() {          return this.progress;      }    @Override      protected void onDetachedFromWindow() {          super.onDetachedFromWindow();          if (thumb_double != null) {              thumb_double.setCallback(null);              thumb_double = null;          }      }}

然后是XML，因为要用到自定义属性```xml    <?xml version="1.0" encoding="utf-8"?>      <resources>          <!-- 参考Seekbar -->          <declare-styleable name="windows">              <!-- 背景颜色 -->              <attr name="background" format="color" />              <!-- 进度颜色 -->              <attr name="progressDrawable" format="color" />              <!-- 宽度 -->              <attr name="layout_width" format="dimension" />              <!-- 字体颜色 -->              <attr name="textColor" format="color" />              <!-- 字体大小 -->              <attr name="textSize" format="dimension" />              <!-- 最大进度 -->              <attr name="max" format="integer" />              <!-- 进度 -->              <attr name="progress" format="integer" />              <!-- 进度点 -->              <attr name="thumb" format="reference" />              <!-- 进度点宽高 -->              <attr name="thumbSize" format="integer" />          </declare-styleable>      </resources>  

最后是在代码里的用法```xml <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"
tools:context=".MainActivity" >

    <com.windows.canvas.CycleView          android:layout_centerInParent="true"          xmlns:windows="http://schemas.android.com/apk/res/com.finals.canvas"          android:layout_width="150dp"          android:layout_height="150dp" /></RelativeLayout>

```