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1、概述

最近需要用进度条，秉着不重复造轮子的原则，上github上搜索了一番，看了几个觉得比较好看的ProgressBar，比如：daimajia的等。简单看了下代码，基本都是继承自View，彻彻底底的自定义了一个进度条。盯着那绚丽滚动条，忽然觉得，为什么要通过View去写一个滚动条，系统已经提供了ProgressBar以及属于它的特性，我们没必要重新去构建一个，但是系统的又比较丑，不同版本变现还不一定一样。那么得出我们的目标：改变系统ProgressBar的样子。 

  对没错，我们没有必要去从0打造一个ProgressBar，人家虽然长的不好看，但是特性以及稳定性还是刚刚的，我们只需要为其整下容就ok了。 

说到整容，大家都知道我们的控件是通过onDraw()画出来的，那么我们只需要去覆盖它的onDraw()方法，自己写下就ok 。 

对了，我创建了一个微信公众号，欢迎关注，左边栏目上扫一扫即可。

  接下来，我们贴下效果图：

2、效果图

1、横向的进度条

2、圆形的进度条

没错，这就是我们的进度条效果，横向的模仿了daimajia的进度条样子。不过我们继承子ProgressBar，简单的为其整个容，代码清晰易懂 。为什么说，易懂呢？

横向那个进度条，大家会drawLine()和drawText()吧，那么通过getWidth()拿到控件的宽度，再通过getProgress()拿到进度，按比例控制绘制线的长短，字的位置还不是分分钟的事。

github源码地址：Android-ProgressBarWidthNumber欢迎大家star or fork 。

3、实现

横向的滚动条绘制肯定需要一些属性，比如已/未到达进度的颜色、宽度，文本的颜色、大小等。
本来呢，我是想通过系统ProgressBar的progressDrawable，从里面提取一些属性完成绘制需要的参数的。但是，最终呢，反而让代码变得复杂。所以最终还是改用自定义属性。 说道自定义属性，大家应该已经不陌生了。

1、HorizontalProgressBarWithNumber

1、自定义属性

values/attr_progress_bar.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources><declare-styleable name="HorizontalProgressBarWithNumber"><attr name="progress_unreached_color" format="color" /><attr name="progress_reached_color" format="color" /><attr name="progress_reached_bar_height" format="dimension" /><attr name="progress_unreached_bar_height" format="dimension" /><attr name="progress_text_size" format="dimension" /><attr name="progress_text_color" format="color" /><attr name="progress_text_offset" format="dimension" /><attr name="progress_text_visibility" format="enum"><enum name="visible" value="0" /><enum name="invisible" value="1" /></attr></declare-styleable><declare-styleable name="RoundProgressBarWidthNumber"><attr name="radius" format="dimension" /></declare-styleable></resources>

2、构造中获取

public class HorizontalProgressBarWithNumber extends ProgressBar
{private static final int DEFAULT_TEXT_SIZE = 10;private static final int DEFAULT_TEXT_COLOR = 0XFFFC00D1;private static final int DEFAULT_COLOR_UNREACHED_COLOR = 0xFFd3d6da;private static final int DEFAULT_HEIGHT_REACHED_PROGRESS_BAR = 2;private static final int DEFAULT_HEIGHT_UNREACHED_PROGRESS_BAR = 2;private static final int DEFAULT_SIZE_TEXT_OFFSET = 10;/*** painter of all drawing things*/protected Paint mPaint = new Paint();/*** color of progress number*/protected int mTextColor = DEFAULT_TEXT_COLOR;/*** size of text (sp)*/protected int mTextSize = sp2px(DEFAULT_TEXT_SIZE);/*** offset of draw progress*/protected int mTextOffset = dp2px(DEFAULT_SIZE_TEXT_OFFSET);/*** height of reached progress bar*/protected int mReachedProgressBarHeight = dp2px(DEFAULT_HEIGHT_REACHED_PROGRESS_BAR);/*** color of reached bar*/protected int mReachedBarColor = DEFAULT_TEXT_COLOR;/*** color of unreached bar*/protected int mUnReachedBarColor = DEFAULT_COLOR_UNREACHED_COLOR;/*** height of unreached progress bar*/protected int mUnReachedProgressBarHeight = dp2px(DEFAULT_HEIGHT_UNREACHED_PROGRESS_BAR);/*** view width except padding*/protected int mRealWidth;protected boolean mIfDrawText = true;protected static final int VISIBLE = 0;public HorizontalProgressBarWithNumber(Context context, AttributeSet attrs){this(context, attrs, 0);}public HorizontalProgressBarWithNumber(Context context, AttributeSet attrs,int defStyle){super(context, attrs, defStyle);setHorizontalScrollBarEnabled(true);obtainStyledAttributes(attrs);mPaint.setTextSize(mTextSize);mPaint.setColor(mTextColor);}/*** get the styled attributes* * @param attrs*/private void obtainStyledAttributes(AttributeSet attrs){// init values from custom attributesfinal TypedArray attributes = getContext().obtainStyledAttributes(attrs, R.styleable.HorizontalProgressBarWithNumber);mTextColor = attributes.getColor(R.styleable.HorizontalProgressBarWithNumber_progress_text_color,DEFAULT_TEXT_COLOR);mTextSize = (int) attributes.getDimension(R.styleable.HorizontalProgressBarWithNumber_progress_text_size,mTextSize);mReachedBarColor = attributes.getColor(R.styleable.HorizontalProgressBarWithNumber_progress_reached_color,mTextColor);mUnReachedBarColor = attributes.getColor(R.styleable.HorizontalProgressBarWithNumber_progress_unreached_color,DEFAULT_COLOR_UNREACHED_COLOR);mReachedProgressBarHeight = (int) attributes.getDimension(R.styleable.HorizontalProgressBarWithNumber_progress_reached_bar_height,mReachedProgressBarHeight);mUnReachedProgressBarHeight = (int) attributes.getDimension(R.styleable.HorizontalProgressBarWithNumber_progress_unreached_bar_height,mUnReachedProgressBarHeight);mTextOffset = (int) attributes.getDimension(R.styleable.HorizontalProgressBarWithNumber_progress_text_offset,mTextOffset);int textVisible = attributes.getInt(R.styleable.HorizontalProgressBarWithNumber_progress_text_visibility,VISIBLE);if (textVisible != VISIBLE){mIfDrawText = false;}attributes.recycle();}

3、onMeasure

刚才不是出onDraw里面写写就行了么，为什么要改onMeasure呢，主要是因为我们所有的属性比如进度条宽度让用户自定义了，所以我们的测量也得稍微变下。

	@Overrideprotected synchronized void onMeasure(int widthMeasureSpec,int heightMeasureSpec){int heightMode = MeasureSpec.getMode(heightMeasureSpec);if (heightMode != MeasureSpec.EXACTLY){float textHeight = (mPaint.descent() + mPaint.ascent());int exceptHeight = (int) (getPaddingTop() + getPaddingBottom() + Math.max(Math.max(mReachedProgressBarHeight,mUnReachedProgressBarHeight), Math.abs(textHeight)));heightMeasureSpec = MeasureSpec.makeMeasureSpec(exceptHeight,MeasureSpec.EXACTLY);}super.onMeasure(widthMeasureSpec, heightMeasureSpec);}

测量完，就到我们的onDraw了~~~

4、onDraw

@Overrideprotected synchronized void onDraw(Canvas canvas){canvas.save();//画笔平移到指定paddingLeft， getHeight() / 2位置，注意以后坐标都为以此为0，0canvas.translate(getPaddingLeft(), getHeight() / 2);boolean noNeedBg = false;//当前进度和总值的比例float radio = getProgress() * 1.0f / getMax();//已到达的宽度float progressPosX = (int) (mRealWidth * radio);//绘制的文本String text = getProgress() + "%";//拿到字体的宽度和高度float textWidth = mPaint.measureText(text);float textHeight = (mPaint.descent() + mPaint.ascent()) / 2;//如果到达最后，则未到达的进度条不需要绘制if (progressPosX + textWidth > mRealWidth){progressPosX = mRealWidth - textWidth;noNeedBg = true;}// 绘制已到达的进度float endX = progressPosX - mTextOffset / 2;if (endX > 0){mPaint.setColor(mReachedBarColor);mPaint.setStrokeWidth(mReachedProgressBarHeight);canvas.drawLine(0, 0, endX, 0, mPaint);}// 绘制文本if (mIfDrawText){mPaint.setColor(mTextColor);canvas.drawText(text, progressPosX, -textHeight, mPaint);}// 绘制未到达的进度条if (!noNeedBg){float start = progressPosX + mTextOffset / 2 + textWidth;mPaint.setColor(mUnReachedBarColor);mPaint.setStrokeWidth(mUnReachedProgressBarHeight);canvas.drawLine(start, 0, mRealWidth, 0, mPaint);}canvas.restore();}@Overrideprotected void onSizeChanged(int w, int h, int oldw, int oldh){super.onSizeChanged(w, h, oldw, oldh);mRealWidth = w - getPaddingRight() - getPaddingLeft();}

其实核心方法就是onDraw了，但是呢，onDraw也很简单，绘制线、绘制文本、绘制线，结束。

还有两个简单的辅助方法：

	/*** dp 2 px* * @param dpVal*/protected int dp2px(int dpVal){return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,dpVal, getResources().getDisplayMetrics());}/*** sp 2 px* * @param spVal* @return*/protected int sp2px(int spVal){return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP,spVal, getResources().getDisplayMetrics());}

好了，到此我们的横向进度就结束了，是不是很简单~~如果你是自定义View，你还得考虑progress的更新，考虑状态的销毁与恢复等等复杂的东西。

接下来看我们的RoundProgressBarWidthNumber圆形的进度条。

2、RoundProgressBarWidthNumber 

圆形的进度条和横向的进度条基本变量都是一致的，于是我就让RoundProgressBarWidthNumber extends HorizontalProgressBarWithNumber 了。

然后需要改变的就是测量和onDraw了：

完整代码：

package com.zhy.view;import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint.Cap;
import android.graphics.Paint.Style;
import android.graphics.RectF;
import android.util.AttributeSet;import com.zhy.library.view.R;public class RoundProgressBarWidthNumber extendsHorizontalProgressBarWithNumber {/*** mRadius of view*/private int mRadius = dp2px(30);public RoundProgressBarWidthNumber(Context context) {this(context, null);}public RoundProgressBarWidthNumber(Context context, AttributeSet attrs) {super(context, attrs);mReachedProgressBarHeight = (int) (mUnReachedProgressBarHeight * 2.5f);TypedArray ta = context.obtainStyledAttributes(attrs,R.styleable.RoundProgressBarWidthNumber);mRadius = (int) ta.getDimension(R.styleable.RoundProgressBarWidthNumber_radius, mRadius);ta.recycle();mTextSize = sp2px(14);mPaint.setStyle(Style.STROKE);mPaint.setAntiAlias(true);mPaint.setDither(true);mPaint.setStrokeCap(Cap.ROUND);}@Overrideprotected synchronized void onMeasure(int widthMeasureSpec,int heightMeasureSpec) {int heightMode = MeasureSpec.getMode(heightMeasureSpec);int widthMode = MeasureSpec.getMode(widthMeasureSpec);int paintWidth = Math.max(mReachedProgressBarHeight,mUnReachedProgressBarHeight);if (heightMode != MeasureSpec.EXACTLY) {int exceptHeight = (int) (getPaddingTop() + getPaddingBottom()+ mRadius * 2 + paintWidth);heightMeasureSpec = MeasureSpec.makeMeasureSpec(exceptHeight,MeasureSpec.EXACTLY);}if (widthMode != MeasureSpec.EXACTLY) {int exceptWidth = (int) (getPaddingLeft() + getPaddingRight()+ mRadius * 2 + paintWidth);widthMeasureSpec = MeasureSpec.makeMeasureSpec(exceptWidth,MeasureSpec.EXACTLY);}super.onMeasure(heightMeasureSpec, heightMeasureSpec);}@Overrideprotected synchronized void onDraw(Canvas canvas) {String text = getProgress() + "%";// mPaint.getTextBounds(text, 0, text.length(), mTextBound);float textWidth = mPaint.measureText(text);float textHeight = (mPaint.descent() + mPaint.ascent()) / 2;canvas.save();canvas.translate(getPaddingLeft(), getPaddingTop());mPaint.setStyle(Style.STROKE);// draw unreaded barmPaint.setColor(mUnReachedBarColor);mPaint.setStrokeWidth(mUnReachedProgressBarHeight);canvas.drawCircle(mRadius, mRadius, mRadius, mPaint);// draw reached barmPaint.setColor(mReachedBarColor);mPaint.setStrokeWidth(mReachedProgressBarHeight);float sweepAngle = getProgress() * 1.0f / getMax() * 360;canvas.drawArc(new RectF(0, 0, mRadius * 2, mRadius * 2), 0,sweepAngle, false, mPaint);// draw textmPaint.setStyle(Style.FILL);canvas.drawText(text, mRadius - textWidth / 2, mRadius - textHeight,mPaint);canvas.restore();}}

绘制的过程呢？

先绘制一个细一点的圆，然后绘制一个粗一点的弧度，二者叠在一起就行。文本呢，绘制在中间~~~总体，没什么代码量。

好了，两个进度条就到这了，是不是发现简单很多。总体设计上，存在些问题，如果抽取一个BaseProgressBar用于获取公共的属性；然后不同样子的进度条继承分别实现自己的测量和样子，这样结构可能会清晰些~~~

4、使用

布局文件

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"xmlns:zhy="http://schemas.android.com/apk/res-auto"android:layout_width="match_parent"android:layout_height="match_parent" ><LinearLayoutandroid:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"android:padding="25dp" ><com.zhy.view.HorizontalProgressBarWithNumberandroid:id="@+id/id_progressbar01"android:layout_width="match_parent"android:layout_height="wrap_content"android:layout_marginTop="50dip"android:padding="5dp" /><com.zhy.view.HorizontalProgressBarWithNumberandroid:layout_width="match_parent"android:layout_height="wrap_content"android:layout_marginTop="50dip"android:padding="5dp"android:progress="50"zhy:progress_text_color="#ffF53B03"zhy:progress_unreached_color="#ffF7C6B7" /><com.zhy.view.RoundProgressBarWidthNumberandroid:id="@+id/id_progress02"android:layout_width="match_parent"android:layout_height="wrap_content"android:layout_marginTop="50dip"android:padding="5dp"android:progress="30" /><com.zhy.view.RoundProgressBarWidthNumberandroid:layout_width="match_parent"android:layout_height="wrap_content"android:layout_marginTop="50dip"android:padding="5dp"android:progress="50"zhy:progress_reached_bar_height="20dp"zhy:progress_text_color="#ffF53B03"zhy:radius="60dp" /></LinearLayout></ScrollView>

package com.zhy.sample.progressbar;import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;import com.zhy.annotation.Log;
import com.zhy.view.HorizontalProgressBarWithNumber;public class MainActivity extends Activity {private HorizontalProgressBarWithNumber mProgressBar;private static final int MSG_PROGRESS_UPDATE = 0x110;private Handler mHandler = new Handler() {@Logpublic void handleMessage(android.os.Message msg) {int progress = mProgressBar.getProgress();mProgressBar.setProgress(++progress);if (progress >= 100) {mHandler.removeMessages(MSG_PROGRESS_UPDATE);}mHandler.sendEmptyMessageDelayed(MSG_PROGRESS_UPDATE, 100);};};@Log@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);mProgressBar = (HorizontalProgressBarWithNumber) findViewById(R.id.id_progressbar01);mHandler.sendEmptyMessage(MSG_PROGRESS_UPDATE);}}

最后，本篇博客的目的呢？就是为了说下，类似ProgressBar这样的控件，如果你只是想去改变显示的样子，完全没必要从0去创建，复写onDraw即可，当然是个人观点，提出供大家参考。

源码点击下载