Android自定义水平渐变进度条

先看进度条的效果：

具体实现：

新建类，继承自view，在ondraw中进行绘制：

import android.content.context;
import android.graphics.canvas;
import android.graphics.lineargradient;
import android.graphics.paint;
import android.graphics.rectf;
import android.graphics.shader;
import android.util.attributeset;
import android.util.log;
import android.view.view;

/**
 *
 * 自定义 进度条
 * created by wenjing.tang on 2017/8/7.
 */

public class customizedprogressbar extends view {

 private float maxcount = 100; //进度条最大值
 private float currentcount; //进度条当前值
 // private paint mpaint ;
 private int mwidth,mheight;
 private context mcontext;

 public customizedprogressbar(context context, attributeset attrs, int defstyleattr) {
  super(context, attrs, defstyleattr);
  initview(context);
 }

 public customizedprogressbar(context context, attributeset attrs) {
  super(context, attrs);
  initview(context);
 }

 public customizedprogressbar(context context) {
  super(context);
  initview(context);
 }

 private void initview(context context) {
  mcontext=context;
 }

 @override
 protected void ondraw(canvas canvas) {
  super.ondraw(canvas);
  paint mpaint = new paint();
  mpaint.setantialias(true);
  int round = mheight/2; //半径

  mpaint.setcolor(getresources().getcolor(r.color.white_alpha)); //设置边框背景颜色
  rectf rectbg = new rectf(0, 0, mwidth, mheight);
  canvas.drawroundrect(rectbg, round, round, mpaint);//绘制 最外面的大 圆角矩形，背景为白色

  float section = currentcount/maxcount; //进度条的比例
  rectf rectprogressbg = new rectf(0, 0, mwidth*section, mheight);

  log.e("customizedprogressbar", currentcount+"");
  log.e("customizedprogressbar", section+"");

  //paint设置setcolor(白色无透明)和setshader，只让setshader生效；不然前面setcolor设置了透明度，透明度会生效，和setshader效果叠加
  mpaint.setcolor(getresources().getcolor(r.color.white));
  mpaint.setshader(getlineargradient());
  canvas.drawroundrect(rectprogressbg, round, round, mpaint); //最左边的圆角矩形

  if (maxcount != currentcount){ //如果不是100%，绘制第三段矩形
   rectf rectprogressbg2 = new rectf(mwidth*section-round, 0, mwidth*section, mheight);
   mpaint.setshader(getlineargradient());
   canvas.drawrect(rectprogressbg2, mpaint);
  }
 }

 private lineargradient lineargradient;
 private lineargradient getlineargradient(){
  if(lineargradient==null){
   lineargradient = new lineargradient(0, 0, getwidth(), mheight, new int[]{mcontext.getresources().getcolor(r.color.progress_color_1),
     mcontext.getresources().getcolor(r.color.progress_color_2)}, null, shader.tilemode.clamp); //根据r文件中的id获取到color
  }
  return lineargradient;
 }

 private int diptopx(int dip) {
  float scale = getcontext().getresources().getdisplaymetrics().density;
  return (int) (dip * scale + 0.5f * (dip >= 0 ? 1 : -1));
 }

 /***
  * 设置最大的进度值
  * @param maxcount 最大的进度值
  */
 public void setmaxcount(float maxcount) {
  this.maxcount = maxcount;
 }

 /***
  * 设置当前的进度值
  * @param currentcount 当前进度值
  */
 public void setcurrentcount(float currentcount) {
  this.currentcount = currentcount > maxcount ? maxcount : currentcount;
  invalidate();
 }

 public float getmaxcount() {
  return maxcount;
 }

 public float getcurrentcount() {
  return currentcount;
 }

 @override
 protected void onmeasure(int widthmeasurespec, int heightmeasurespec) {
  int widthspecmode = measurespec.getmode(widthmeasurespec);
  int widthspecsize = measurespec.getsize(widthmeasurespec);
  int heightspecmode = measurespec.getmode(heightmeasurespec);
  int heightspecsize = measurespec.getsize(heightmeasurespec);
  if (widthspecmode == measurespec.exactly || widthspecmode == measurespec.at_most) {
   mwidth = widthspecsize;
  } else {
   mwidth = 0;
  }
  if (heightspecmode == measurespec.at_most || heightspecmode == measurespec.unspecified) {
   mheight = diptopx(18);
  } else {
   mheight = heightspecsize;
  }
  setmeasureddimension(mwidth, mheight);
 }
}

其中用到的一些资源文件如下：

<!--自定义进度条背景颜色-->
<color name="white_alpha">#0c000000</color>

<!--自定义进度条渐变颜色-->
<color name="progress_color_1">#ff916b</color>
<color name="progress_color_2">#ffa94c</color>

要注意的是，在上面java代码中，mpaint.setcolor(getresources().getcolor(r.color.white));这行很重要，因为进度条总共有三层，第一层是最外面的背景，第二层是进度，第三层如果不是100%才绘制，由于第一层背景有透明度，所以setcolor设置了透明度，但虽然setshader，透明度还是会生效，两者效果叠加，效果是这样：

加上之后，paint 第二次设置 setcolor (白色无透明)和 setshader，只让 setshader 生效，进度条才会达到满意的效果；

用法：

java代码中：

 customizedprogressbar.setmaxcount(100);
 integrity = datacount/total_count *100; //根据自己情况来初始化完整度
 customizedprogressbar.setcurrentcount((int) integrity);
 mtvtdataintegrity.settext("完整度" + (int) integrity +"%");      

xml文件中（不需要文字显示也可以）：

 <relativelayout
     android:layout_width="match_parent"
     android:layout_height="18dp"
     android:layout_marginstart="66dp"
     android:layout_marginend="66dp"
     android:layout_centervertical="true">

     <com.text.widget.customizedprogressbar
      android:id="@+id/progress"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:layout_centerinparent="true"/>

     <textview
      android:id="@+id/tv_data_integrity"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:gravity="center"
      tools:text="完整度35%"
      android:textsize="10sp"
      android:layout_centerinparent="true"/>
 </relativelayout>

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。