一、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。 接下来，我们贴下效果图：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。
二、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 attributes final 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(); }
嗯，看起来代码挺长，其实都是在获取自定义属性，没什么技术含量。
（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。
@Override protected 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); }
宽度我们不变，所以的自定义属性不涉及宽度，高度呢，只考虑不是EXACTLY的情况（用户明确指定了，我们就不管了），根据padding和进度条宽度算出自己想要的，如果非EXACTLY下，我们进行exceptHeight封装，传入给控件进行测量高度。测量完，就到我们的onDraw了~~~（4）onDraw
@Override protected 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0，0 canvas.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(); } @Override protected 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 extends HorizontalProgressBarWithNumber { /** * 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); } @Override protected 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); } @Override protected 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 bar mPaint.setColor(mUnReachedBarColor); mPaint.setStrokeWidth(mUnReachedProgressBarHeight); canvas.drawCircle(mRadius, mRadius, mRadius, mPaint); // draw reached bar mPaint.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 text mPaint.setStyle(Style.FILL); canvas.drawText(text, mRadius - textWidth / 2, mRadius - textHeight, mPaint); canvas.restore(); } }
首先获取它的专有属性mRadius，然后根据此属性去测量，测量完成绘制；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~~~
三、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" > <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:padding="25dp" > <com.zhy.view.HorizontalProgressBarWithNumber android:id="@+id/id_progressbar01" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="50dip" android:padding="5dp" /> <com.zhy.view.HorizontalProgressBarWithNumber android: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.RoundProgressBarWidthNumber android: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.RoundProgressBarWidthNumber android: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>
MainActivity
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() { @Log public 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 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mProgressBar = (HorizontalProgressBarWithNumber) findViewById(R.id.id_progressbar01); mHandler.sendEmptyMessage(MSG_PROGRESS_UPDATE); } }
有我们特有的记忆，亲情之忆友谊之花爱情之树以及遗憾之泪！
