参考网址：/article/140249.htm
package com.customview.view;import android.content.Context;import android.content.res.TypedArray;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.LinearGradient;import android.graphics.Paint;import android.graphics.Shader;import android.graphics.Paint.Cap;import android.graphics.Paint.FontMetrics;import android.graphics.Paint.Style;import android.util.AttributeSet;import android.util.Log;import android.view.View;import com.customview.R;public class GoodProgressView extends View{private int[] mColors = { Color.RED, Color.MAGENTA};//进度条颜色（渐变色的2个点）private int backgroundColor = Color.GRAY;//进度条默认颜色private int textColor = Color.GRAY;//文本颜色private Paint mPaint;//画笔private int progressValue=0;//进度值//private RectF rect;//绘制范围public GoodProgressView(Context context, AttributeSet attrs){this(context, attrs, 0);}public GoodProgressView(Context context){this(context, null);}// 获得我自定义的样式属性 public GoodProgressView(Context context, AttributeSet attrs, int defStyle){super(context, attrs, defStyle);// 获得我们所定义的自定义样式属性 TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.GoodProgressView, defStyle, 0);int n = a.getIndexCount();for (int i = 0; i < n; i++){int attr = a.getIndex(i);if (attr==R.styleable.GoodProgressView_startColor){// 渐变色之起始颜色，默认设置为红色mColors[0] = a.getColor(attr, Color.RED);}else if (attr==R.styleable.GoodProgressView_endColor){// 渐变色之结束颜色，默认设置为品红mColors[1] = a.getColor(attr, Color.MAGENTA);}else if (attr==R.styleable.GoodProgressView_gpv_backgroundColor){// 进度条默认颜色，默认设置为灰色backgroundColor = a.getColor(attr, Color.GRAY);}else if (attr==R.styleable.GoodProgressView_gpv_textColor){// 文字颜色，默认设置为灰色textColor = a.getColor(attr, Color.GRAY);}}a.recycle();mPaint = new Paint();progressValue=0;}public void setProgressValue(int progressValue){if(progressValue>100){progressValue = 100;}this.progressValue = progressValue;Log.i("customView","log: progressValue="+progressValue);}public void setColors(int[] colors){mColors = colors;}//在ScrollView中使用自定义View需要重写该方法@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){int width = 0;int height = 0;/*** 设置宽度*/int specMode = MeasureSpec.getMode(widthMeasureSpec);int specSize = MeasureSpec.getSize(widthMeasureSpec);switch (specMode){case MeasureSpec.EXACTLY:// 明确指定了width = specSize;break;case MeasureSpec.AT_MOST:// 一般为WARP_CONTENTwidth = getPaddingLeft() + getPaddingRight() ;break;}/*** 设置高度*/specMode = MeasureSpec.getMode(heightMeasureSpec);specSize = MeasureSpec.getSize(heightMeasureSpec);switch (specMode){case MeasureSpec.EXACTLY:// 明确指定了height = specSize;break;case MeasureSpec.AT_MOST:// 一般为WARP_CONTENTheight = width/10;break;}Log.i("customView","log: w="+width+" h="+height);setMeasuredDimension(width, height);}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);int mWidth = getMeasuredWidth();int mHeight = getMeasuredHeight();//按比例计算进度条各部分的值float unit = Math.min(((float)mWidth)/300, ((float)mHeight)/30);float lineWidth = 5*unit;//线粗float innerCircleDiameter = 6*unit;//内圆直径float outerCircleDiameter = 10*unit;//外圆直径float wordHeight = 12*unit;//字高//9*unit//float wordWidth = 26*unit;//字长float offsetLength = 5*unit;//留空//float width = 300*unit;//绘画区域的长度float height = 30*unit;//绘画区域的高度float progressWidth = 258*unit;//绘画区域的长度mPaint.setAntiAlias(true);mPaint.setStrokeWidth((float) lineWidth );mPaint.setStyle(Style.STROKE);mPaint.setStrokeCap(Cap.ROUND);mPaint.setColor(Color.TRANSPARENT);float offsetHeight=height/2;float offsetWidth=offsetLength;float section = ((float)progressValue) / 100;if(section>1)section=1;int count = mColors.length;int[] colors = new int[count];System.arraycopy(mColors, 0, colors, 0, count);//底部灰色背景，指示进度条总长度mPaint.setShader(null);mPaint.setColor(backgroundColor);canvas.drawLine(offsetWidth+section * progressWidth, offsetHeight, offsetWidth+progressWidth, offsetHeight, mPaint);//设置渐变色区域LinearGradient shader = new LinearGradient(0, 0, offsetWidth*2+progressWidth , 0, colors, null,Shader.TileMode.CLAMP);mPaint.setShader(shader);//画出渐变色进度条canvas.drawLine(offsetWidth, offsetHeight, offsetWidth+section*progressWidth, offsetHeight, mPaint);//渐变色外圆mPaint.setStrokeWidth(1);mPaint.setStyle(Paint.Style.FILL);canvas.drawCircle(offsetWidth+section * progressWidth, offsetHeight, outerCircleDiameter/2, mPaint);//绘制两条斜线，使外圆到进度条的连接更自然if(section*100>1.8){mPaint.setStrokeWidth(2*unit);canvas.drawLine(offsetWidth+section * progressWidth-6*unit, offsetHeight-(float)1.5*unit, offsetWidth+section * progressWidth-1*unit,offsetHeight-(float)3.8*unit, mPaint);canvas.drawLine(offsetWidth+section * progressWidth-6*unit, offsetHeight+(float)1.5*unit, offsetWidth+section * progressWidth-1*unit,offsetHeight+(float)3.8*unit, mPaint);}//白色内圆mPaint.setShader(null);mPaint.setColor(Color.WHITE);canvas.drawCircle(offsetWidth+section * progressWidth, offsetHeight, innerCircleDiameter/2, mPaint);//白色内圆//绘制文字--百分比mPaint.setStrokeWidth(2*unit);mPaint.setColor(textColor);mPaint.setTextSize(wordHeight);//计算坐标使文字居中FontMetrics fontMetrics = mPaint.getFontMetrics(); float fontHeight = fontMetrics.bottom - fontMetrics.top;float baseY = height/2 + fontHeight/2 - fontMetrics.bottom;canvas.drawText(""+progressValue+"%", progressWidth+2*offsetWidth, baseY, mPaint);//略微偏下，baseline}}
res/values/attr.xml
<declare-styleable name="GoodProgressView"><attr name="startColor" format="color"/><attr name="endColor" format="color"/><attr name="gpv_backgroundColor" format="color"/><attr name="gpv_textColor" format="color"/></declare-styleable>
布局中使用
<com.customview.view.GoodProgressView android:id="@+id/good_progress_view1" android:layout_width="match_parent" android:layout_height="wrap_content" android:padding="10dp"/>
代码中指定渐变色
good_progress_view1 = (GoodProgressView)findViewById(R.id.good_progress_view1);good_progress_view2.setColors(randomColors());//随机生成颜色private int[] randomColors() {int[] colors=new int[2];Random random = new Random();int r,g,b;for(int i=0;i<2;i++){r=random.nextInt(256);g=random.nextInt(256);b=random.nextInt(256);colors[i]= Color.argb(255, r, g, b);}return colors;}
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