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
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<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" />
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