Android实现底部带刻度的进度条样式

由于公司需要一个带刻度的进度条样式，网上找了一圈，有些是加个刻度的背景图片，这样对于我的项目来说，不合适，因为刻度需要动态去改变，所以换背景图片的方案肯定是不行的，唯一的办法就是自己绘制一个进度条，进度条的绘制相对来说是比较简单的。我自己对自定义控件这一块也不是很了解，全当学习一下吧，写这篇博客也是记录一下，如果有人也有这样样式的进度条需求，也可以直接拿过去用，比较自己也用过很多大神的东西。

        开始就先上图吧

样式就是上图这样了，由于是通过canvas绘制的，所以想要的样式都可以自己去绘制，我这边就搞一个简单的就行了。

首先得继承View，由于这个控件比较简单，我就没有搞那种在布局文件中设值的属性了，继承之后第一步，需要测量布局，得到画布的大小，这个值其实就是我们在布局文件中设置的控件的宽高。  

@Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    int realWidth = startMeasure(widthMeasureSpec);
    int realHeight = startMeasure(heightMeasureSpec);
 
    setMeasuredDimension(realWidth, realHeight);
  }
 private int startMeasure(int msSpec) {
    int result = 0;
    int mode = MeasureSpec.getMode(msSpec);
    int size = MeasureSpec.getSize(msSpec);
    if (mode == MeasureSpec.EXACTLY) {
      result = size;
    } else {
      result = PxUtils.dpToPx(400, mContext);
    }
    return result;
  }

这边拿到画布的大小，设置进度条显示的宽度，我这边设置的为画布宽度的80%

@Override
  protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    super.onSizeChanged(w, h, oldw, oldh);
    mWidth = getWidth();
    mHight = getHeight();
    progressWidth = mWidth*0.8f;
  }

然后就是初始化画笔了，具体我就不多赘述了，我使用了五个画笔，分别是进度条背景底框，进度，刻度绘制，刻度下的字，当前数值的文字具体看代码。

private void initPaint() {
    //画进度条静态空心背景
    paintProgressBackground = new Paint();
    paintProgressBackground.setAntiAlias(true);
    paintProgressBackground.setStyle(Paint.Style.STROKE);
    paintProgressBackground.setColor(getResources().getColor(R.color.progressborder));
    paintProgressBackground.setDither(true);
    //画进度的画笔，实心
    paintProgress = new Paint();
    paintProgress.setAntiAlias(true);
    paintProgress.setStyle(Paint.Style.FILL);
    paintProgress.setColor(getResources().getColor(R.color.progressfill));
    paintProgress.setDither(true);
    //画刻度的画笔
    paintNum = new Paint();
    paintNum.setAntiAlias(true);
    paintNum.setColor(getResources().getColor(R.color.progresstext));
    paintNum.setStrokeWidth(2);
    paintNum.setStyle(Paint.Style.FILL);
    paintNum.setDither(true);
    //画刻度数值的画笔
    paintTikeStr = new Paint();
    paintTikeStr.setAntiAlias(true);
    paintTikeStr.setStyle(Paint.Style.FILL);
    paintTikeStr.setTextAlign(Paint.Align.LEFT);
    paintTikeStr.setColor(getResources().getColor(R.color.progresstext));
    paintTikeStr.setTextSize(16);
    //画数值的画笔
    paintText = new Paint();
    paintText.setAntiAlias(true);
    paintText.setColor(getResources().getColor(R.color.progresstext));
    paintText.setStrokeWidth(1);
    paintText.setStyle(Paint.Style.FILL);//实心画笔
    paintText.setDither(true);
 
  }

接下来就是onDraw方法进行绘制了，用canvas绘制，绘制的起点是你画布的左上角，横向为x，纵向为y，所以绘制的时候只要确定好x,y的坐标，那就好画了。

  @Override
  protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    
    //进度条的底框
    canvas.drawRect(0+leftPadding,0,progressWidth+leftPadding,progressHeight,paintProgressBackground);
    //进度条的当前进度
    canvas.drawRect(0+leftPadding,0,progressWidth*percent+leftPadding,progressHeight,paintProgress);
    drawScale(canvas,percent);
 
    drawText(canvas,percent);
  }

进度条其实很容易绘制，就是画两个矩形，一个地没有进度的矩形，另一个是当前进度的矩形就行了 ，percent是当前进度的百分比，之所以加个leftPadding是因为如果从0开始就顶到画布左边了，后面画刻度下的字体就会存在截断现象，显示不全。drawRect的每个参数是什么意思我就不多说了，这个很多文章都有介绍。

 /**
   * 绘制刻度和刻度下的数字
   * @param canvas
   * @param percent
   */
  private void drawScale(Canvas canvas,float percent){
    float span = progressWidth/8f;
    for (int i=0;i<9;i++){
      canvas.save(); //记录画布状态
      canvas.translate(span*i+leftPadding, 0);
      canvas.drawLine(0,numY,0,numY+10,paintNum);
      String text = String.valueOf(tikeStrArray[i]);
      Paint.FontMetricsInt fontMetrics = paintTikeStr.getFontMetricsInt();
      float baseline = ((numY + 20) + (fontMetrics.bottom - fontMetrics.top) / 2);
      canvas.drawText(text, -getTextViewLength(paintTikeStr, text) / 2, baseline, paintTikeStr);
      canvas.restore();
    }
  }

跟其他进度条不同的是，带刻度的最重要是怎么绘制刻度了，我这边默认总共9个刻度，可以自行修改，怎么画出刻度线，重要的就是通过canvas的平移，translate来实现，x为每次绘制的位置，画一条就会平移一段距离再画一条，原理就是这样。numY的参数其实就是与画布顶点的距离，由于我的进度条设置的是30的高度，刻度要紧挨着进度底部，所以开始画的y坐标也是30，+10是绘制刻度线的长度，所以刻度线长度就是10。刻度下的文字，也是获取文字的宽度，取中心位置。

  private float getTextViewLength(Paint paint, String text) {
    if (TextUtils.isEmpty(text)) return 0;
    float textLength = paint.measureText(text);
    return textLength;
  }

接下来就是绘制右边显示当前数组的文字了，只要确定好位置，就很简单了。

  * 绘制显示的数值
   * @param canvas
   * @param percent
   */
  private void drawText(Canvas canvas, float percent) {
    if (TextUtils.isEmpty(unit)) return;
    float length;
    paintText.setTextSize(16);
    numerical = StringUtil.floatFormat(startNum + (maxNum - startNum) * percent) + unit;
    length = paintText.measureText(numerical);
    canvas.drawText(numerical,progressWidth+leftPadding+textSpan , length / 2, paintText);
  }

显示的值是多少，也很简单算出来，具体怎么算的再上面的代码中。

基本上这个进度条就完工了，由于是做记录，就没写的很详细了，下面贴一下全部代码。

package com.anderson.dashboardview.view;
 import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import com.anderson.dashboardview.R;
import com.anderson.dashboardview.util.PxUtils;
import com.anderson.dashboardview.util.StringUtil;
/**
 * 带刻度的进度条
 */
public class HorizontalProgressBar extends View {
  private Context mContext;
  private Paint paintProgressBackground;
  private Paint paintProgress;
  private Paint paintNum;
  private Paint paintTikeStr;
  private int mWidth, mHight;
  private float percent = 0;
  private float progressWidth = 320;
  private float startNum;//开始的数值
  private float maxNum;//最大的数值
  private float[] tikeStrArray = null;
  private int tikeGroup;
  private int mTikeCount;//刻度的个数
  private Paint paintText;
  private String unit = "m";//显示单位
  private String numerical;
  private int leftPadding = 25;//左边距
  private int textSpan = 2;//数值文字与进度条的间隔
  private int progressHeight = 30;//进度条高度
  private float numY = 30;//在进度条底部绘制，相当于进度条的高度
  public HorizontalProgressBar(Context context) {
    super(context);
    init(context);
  }
  public HorizontalProgressBar(Context context, AttributeSet attrs) {
    super(context, attrs);
    init(context);
  }
  public HorizontalProgressBar(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    init(context);
  }
  private void init(Context context) {
    mContext = context;
    initPaint();
  }
  private void initPaint() {
    //画进度条静态空心背景
    paintProgressBackground = new Paint();
    paintProgressBackground.setAntiAlias(true);
    paintProgressBackground.setStyle(Paint.Style.STROKE);
    paintProgressBackground.setColor(getResources().getColor(R.color.progressborder));
    paintProgressBackground.setDither(true);
    //画进度的画笔，实心
    paintProgress = new Paint();
    paintProgress.setAntiAlias(true);
    paintProgress.setStyle(Paint.Style.FILL);
    paintProgress.setColor(getResources().getColor(R.color.progressfill));
    paintProgress.setDither(true);
    //画刻度的画笔
    paintNum = new Paint();
    paintNum.setAntiAlias(true);
    paintNum.setColor(getResources().getColor(R.color.progresstext));
    paintNum.setStrokeWidth(2);
    paintNum.setStyle(Paint.Style.FILL);
    paintNum.setDither(true);
    //画刻度数值的画笔
    paintTikeStr = new Paint();
    paintTikeStr.setAntiAlias(true);
    paintTikeStr.setStyle(Paint.Style.FILL);
    paintTikeStr.setTextAlign(Paint.Align.LEFT);
    paintTikeStr.setColor(getResources().getColor(R.color.progresstext));
    paintTikeStr.setTextSize(16);
    //画数值的画笔
    paintText = new Paint();
    paintText.setAntiAlias(true);
    paintText.setColor(getResources().getColor(R.color.progresstext));
    paintText.setStrokeWidth(1);
    paintText.setStyle(Paint.Style.FILL);//实心画笔
    paintText.setDither(true);
  }
  @Override
  protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    super.onSizeChanged(w, h, oldw, oldh);
    mWidth = getWidth();
    mHight = getHeight();
    progressWidth = mWidth*0.8f;
  }
  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    int realWidth = startMeasure(widthMeasureSpec);
    int realHeight = startMeasure(heightMeasureSpec);
    setMeasuredDimension(realWidth, realHeight);
  }
  private int startMeasure(int msSpec) {
    int result = 0;
    int mode = MeasureSpec.getMode(msSpec);
    int size = MeasureSpec.getSize(msSpec);
    if (mode == MeasureSpec.EXACTLY) {
      result = size;
    } else {
      result = PxUtils.dpToPx(400, mContext);
    }
    return result;
  }
  private float getTextViewLength(Paint paint, String text) {
    if (TextUtils.isEmpty(text)) return 0;
    float textLength = paint.measureText(text);
    return textLength;
  }
  @Override
  protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    //进度条的底框
    canvas.drawRect(0+leftPadding,0,progressWidth+leftPadding,progressHeight,paintProgressBackground);
    //进度条的当前进度
    canvas.drawRect(0+leftPadding,0,progressWidth*percent+leftPadding,progressHeight,paintProgress);
    drawScale(canvas,percent);
    drawText(canvas,percent);
  }
  /**
   * 绘制刻度和刻度下的数字
   * @param canvas
   * @param percent
   */
  private void drawScale(Canvas canvas,float percent){
    float span = progressWidth/8f;
    for (int i=0;i<9;i++){
      canvas.save(); //记录画布状态
      canvas.translate(span*i+leftPadding, 0);
      canvas.drawLine(0,numY,0,numY+10,paintNum);
      String text = String.valueOf(tikeStrArray[i]);
      Paint.FontMetricsInt fontMetrics = paintTikeStr.getFontMetricsInt();
      float baseline = ((numY + 20) + (fontMetrics.bottom - fontMetrics.top) / 2);
      canvas.drawText(text, -getTextViewLength(paintTikeStr, text) / 2, baseline, paintTikeStr);
      canvas.restore();
    }
  }
  /**
   * 绘制显示的数值
   * @param canvas
   * @param percent
   */
  private void drawText(Canvas canvas, float percent) {
    if (TextUtils.isEmpty(unit)) return;
    float length;
    paintText.setTextSize(16);
    numerical = StringUtil.floatFormat(startNum + (maxNum - startNum) * percent) + unit;
    length = paintText.measureText(numerical);
    canvas.drawText(numerical,progressWidth+leftPadding+textSpan , length / 2, paintText);
  }
  /**
   * 设置百分比
   * @param percent
   */
  public void setPercent(int percent) {
     this.percent = percent / 100f;
    invalidate();
  }
  /**
   * 设置起始值
   * @param startNum
   */
  public void setStartNum(float startNum) {
    this.startNum = startNum;
  }
  /**
   * 设置最大值
   * @param maxNum
   */
  public void setMaxNum(float maxNum) {
    this.maxNum = maxNum;
    float[] tikeintArray = new float[9];
    //默认8个大刻度
    tikeintArray[0] = startNum;
    for (int i = 1;i<8;i++){
      tikeintArray[i] = tikeintArray[i-1]+((maxNum-startNum)/8);
    }
    tikeintArray[8] = maxNum;
    setTikeArray(tikeintArray);
  }
  public void setTikeArray(float[] array){
    this.tikeStrArray = array;
    tikeGroup = 5; // 默认1个长刻度间隔4个短刻度，加起来一组5
    if (tikeStrArray != null && tikeStrArray.length != 0) {
      //根据需要绘制的刻度数组大小计算刻度总数
      mTikeCount = (tikeStrArray.length - 1) * tikeGroup + 1;
    } else {
      tikeStrArray = new float[0];
      mTikeCount = 36;
    }
  }
}

总结

以上所述是小编给大家介绍的Android实现底部带刻度的进度条样式,希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对自由互联网站的支持！
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