Android自定义view渐变圆形动画

本文实例为大家分享了android自定义view渐变圆形动画的具体代码，供大家参考，具体内容如下

直接上效果图

自定义属性

attrs.xml文件

<resources>
  <declare-styleable name="progressring">
    <!--进度起始色-->
    <attr name="pr_progress_start_color" format="color" />
    <!--进度结束色-->
    <attr name="pr_progress_end_color" format="color" />
    <!--背景起始色-->
    <attr name="pr_bg_start_color" format="color" />
    <!--背景中间色-->
    <attr name="pr_bg_mid_color" format="color" />
    <!--背景结束色-->
    <attr name="pr_bg_end_color" format="color" />
    <!--进度值 介于0-100-->
    <attr name="pr_progress" format="integer" />
    <!--进度宽度-->
    <attr name="pr_progress_width" format="dimension" />
    <!--起始角度-->
    <attr name="pr_start_angle" format="integer" />
    <!--扫过的角度-->
    <attr name="pr_sweep_angle" format="integer" />
    <!--是否显示动画-->
    <attr name="pr_show_anim" format="boolean" />
  </declare-styleable>

</resources>

创建一个类 progressring继承自 view

public class progressring extends view {

  private int progressstartcolor;
  private int progressendcolor;
  private int bgstartcolor;
  private int bgmidcolor;
  private int bgendcolor;
  private int progress;
  private float progresswidth;
  private int startangle;
  private int sweepangle;
  private boolean showanim;

  private int mmeasureheight;
  private int mmeasurewidth;

  private paint bgpaint = new paint(paint.anti_alias_flag | paint.dither_flag);
  private paint progresspaint = new paint(paint.anti_alias_flag | paint.dither_flag);

  private rectf prectf;

  private float unitangle;

  private int curprogress = 0;

  public progressring(context context, attributeset attrs) {
    super(context, attrs);
    typedarray ta = context.obtainstyledattributes(attrs, r.styleable.progressring);
    progressstartcolor = ta.getcolor(r.styleable.progressring_pr_progress_start_color, color.yellow);
    progressendcolor = ta.getcolor(r.styleable.progressring_pr_progress_end_color, progressstartcolor);
    bgstartcolor = ta.getcolor(r.styleable.progressring_pr_bg_start_color, color.ltgray);
    bgmidcolor = ta.getcolor(r.styleable.progressring_pr_bg_mid_color, bgstartcolor);
    bgendcolor = ta.getcolor(r.styleable.progressring_pr_bg_end_color, bgstartcolor);
    progress = ta.getint(r.styleable.progressring_pr_progress, 0);
    progresswidth = ta.getdimension(r.styleable.progressring_pr_progress_width, 8f);
    startangle = ta.getint(r.styleable.progressring_pr_start_angle, 150);
    sweepangle = ta.getint(r.styleable.progressring_pr_sweep_angle, 240);
    showanim = ta.getboolean(r.styleable.progressring_pr_show_anim, true);
    ta.recycle();

    unitangle = (float) (sweepangle / 100.0);

    bgpaint.setstyle(paint.style.stroke);
    bgpaint.setstrokecap(paint.cap.round);
    bgpaint.setstrokewidth(progresswidth);

    progresspaint.setstyle(paint.style.stroke);
    progresspaint.setstrokecap(paint.cap.round);
    progresspaint.setstrokewidth(progresswidth);

  }

  @override
  protected void ondraw(canvas canvas) {
    super.ondraw(canvas);

    /*for (int i = 0, end = (int) (progress * unitangle); i <= end; i++) {
      progresspaint.setcolor(getgradient(i / (float) end, progressstartcolor, progressendcolor));
      canvas.drawarc(prectf,
          startangle + i,
          1,
          false,
          progresspaint);
    }*/
    if (!showanim) {
      curprogress = progress;
    }

    drawbg(canvas);
    drawprogress(canvas);

    if (curprogress < progress) {
      curprogress++;
      postinvalidate();
    }
  }

  // 只需要画进度之外的背景即可
  private void drawbg(canvas canvas) {
    float halfsweep = sweepangle / 2;
    for (int i = sweepangle, st = (int) (curprogress * unitangle); i > st; --i) {
      if (i - halfsweep > 0) {
        bgpaint.setcolor(getgradient((i - halfsweep) / halfsweep, bgmidcolor, bgendcolor));
      } else {
        bgpaint.setcolor(getgradient((halfsweep - i) / halfsweep, bgmidcolor, bgstartcolor));
      }
      canvas.drawarc(prectf,
          startangle + i,
          1,
          false,
          bgpaint);
    }
  }

  private void drawprogress(canvas canvas) {
    for (int i = 0, end = (int) (curprogress * unitangle); i <= end; i++) {
      progresspaint.setcolor(getgradient(i / (float) end, progressstartcolor, progressendcolor));
      canvas.drawarc(prectf,
          startangle + i,
          1,
          false,
          progresspaint);
    }
  }

  public void setprogress(@intrange(from = 0, to = 100) int progress) {
    this.progress = progress;
    invalidate();
  }

  public int getprogress() {
    return progress;
  }

  public int getgradient(float fraction, int startcolor, int endcolor) {
    if (fraction > 1) fraction = 1;
    int alphastart = color.alpha(startcolor);
    int redstart = color.red(startcolor);
    int bluestart = color.blue(startcolor);
    int greenstart = color.green(startcolor);
    int alphaend = color.alpha(endcolor);
    int redend = color.red(endcolor);
    int blueend = color.blue(endcolor);
    int greenend = color.green(endcolor);
    int alphadifference = alphaend - alphastart;
    int reddifference = redend - redstart;
    int bluedifference = blueend - bluestart;
    int greendifference = greenend - greenstart;
    int alphacurrent = (int) (alphastart + fraction * alphadifference);
    int redcurrent = (int) (redstart + fraction * reddifference);
    int bluecurrent = (int) (bluestart + fraction * bluedifference);
    int greencurrent = (int) (greenstart + fraction * greendifference);
    return color.argb(alphacurrent, redcurrent, greencurrent, bluecurrent);
  }

  @override
  protected void onmeasure(int widthmeasurespec, int heightmeasurespec) {
    super.onmeasure(widthmeasurespec, heightmeasurespec);
    mmeasurewidth = getmeasuredwidth();
    mmeasureheight = getmeasuredheight();
    if (prectf == null) {
      float halfprogresswidth = progresswidth / 2;
      prectf = new rectf(halfprogresswidth + getpaddingleft(),
          halfprogresswidth + getpaddingtop(),
          mmeasurewidth - halfprogresswidth - getpaddingright(),
          mmeasureheight - halfprogresswidth - getpaddingbottom());
    }

  }
}

xml布局

<mycircle.progressring
  android:layout_width="320dp"
  android:layout_height="320dp"
  android:layout_gravity="center_horizontal"
  app:pr_bg_end_color="#00ffffff"
  app:pr_bg_mid_color="#cccccc"
  app:pr_bg_start_color="#00ffffff"
  app:pr_progress="70"
  app:pr_progress_end_color="#f78930"
  app:pr_progress_start_color="#00ffffff"
  app:pr_progress_width="40dp" />

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。