前言：相信你看了《Android开发之Paint的高级使用》博客，对Paint有一定的认识，今天我带给大家一篇一个关于paint的小练习，定制我们知己的ProgressBar，这里我们不讨论google给我们提供的ProgressBar，也不讨论基于google的ProgressBar自定义的样式。
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先看下效果图：
废话不多说了，直接看代码：
首先定义几个属性：
<declare-styleable name="CustomProgressBar"> <attr name="roundProgressColor" format="color"></attr> <attr name="roundColor" format="color"></attr> <attr name="roundWidth" format="dimension"></attr> <attr name="textSize" format="dimension"></attr> <attr name="textColor" format="color"></attr> <attr name="max" format="integer"></attr> <attr name="textShow" format="boolean"></attr> <attr name="style"> <enum name="STROKE" value="0"></enum> <enum name="FILL" value="1"></enum> </attr> </declare-styleable>新建CustomProgressBar继承自View： import android.content.Context; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.RectF; import android.graphics.Typeface; import android.support.annotation.Nullable; import android.util.AttributeSet; import android.view.View; /** * Created by Fly on 2017/6/3. */ public class CustomProgressBar extends View { private Paint paint; private int max; private int roundColor; private int roundProgressColor; private int textColor; private float textSize; private float roundWidth; private boolean textShow; private int style; private int progress; public static final int STROKE = 0; public static final int FILL = 1; public CustomProgressBar(Context context, @Nullable AttributeSet attrs) { super(context, attrs); paint = new Paint(); TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.CustomProgressBar); max = typedArray.getInteger(R.styleable.CustomProgressBar_max, 100); roundColor = typedArray.getColor(R.styleable.CustomProgressBar_roundColor, Color.RED); roundProgressColor = typedArray.getColor(R.styleable.CustomProgressBar_roundProgressColor, Color.BLUE); textColor = typedArray.getColor(R.styleable.CustomProgressBar_textColor, Color.GREEN); textSize = typedArray.getDimension(R.styleable.CustomProgressBar_textSize, 55f); roundWidth = typedArray.getDimension(R.styleable.CustomProgressBar_roundWidth, 10); textShow = typedArray.getBoolean(R.styleable.CustomProgressBar_textShow, true); style = typedArray.getInt(R.styleable.CustomProgressBar_style, 0); typedArray.recycle(); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); //画默认的大圆环 int center = getWidth() / 2;//中心坐标点 float radius = center - roundWidth / 2;//半径 paint.setColor(roundColor); paint.setStyle(Paint.Style.STROKE);//设置空心（描边） paint.setStrokeWidth(roundWidth);//圆环的宽度 paint.setAntiAlias(true); canvas.drawCircle(center, center, radius, paint); //画进度百分比 paint.setColor(textColor); paint.setStrokeWidth(0);//圆环的宽度 paint.setTextSize(textSize); paint.setTypeface(Typeface.DEFAULT_BOLD); int percent = (int) (progress / (float) max * 100); //y公式：可以看我的那一片关于文本matrics的分析图 if (textShow && percent != 0 && style == STROKE) { canvas.drawText(percent + "%", (getWidth() - paint.measureText(percent + "%")) / 2f, getWidth() / 2f - (paint.descent() + paint.ascent()) / 2f, paint); } //画圆弧 //矩形区域，定义圆弧的形状的大小 RectF oval = new RectF(center - radius, center - radius, center + radius, center + radius); paint.setColor(roundProgressColor); paint.setStrokeWidth(roundWidth); switch (style) { case STROKE: paint.setStyle(Paint.Style.STROKE); canvas.drawArc(oval, 0, 360 * progress / max, false, paint); break; case FILL: paint.setStyle(Paint.Style.FILL_AND_STROKE); if (progress != 0) canvas.drawArc(oval, 0, 360 * progress / max, true, paint); break; } } public synchronized int getMax() { return max; } public synchronized void setMax(int max) { if (max < 0) { throw new IllegalArgumentException("max不能小于0"); } this.max = max; } public synchronized int getProgress() { return progress; } public synchronized void setProgress(int progress) { if (progress < 0) { throw new IllegalArgumentException("progress不能小于0"); } if (progress > max) { progress = max; this.progress = progress; } if (progress <= max) { this.progress = progress; postInvalidate(); } } public int getRoundColor() { return roundColor; } public void setRoundColor(int roundColor) { this.roundColor = roundColor; } public int getRoundProgressColor() { return roundProgressColor; } public void setRoundProgressColor(int roundProgressColor) { this.roundProgressColor = roundProgressColor; } public int getTextColor() { return textColor; } public void setTextColor(int textColor) { this.textColor = textColor; } public float getTextSize() { return textSize; } public void setTextSize(int textSize) { this.textSize = textSize; } public float getRoundWidth() { return roundWidth; } public void setRoundWidth(int roundWidth) { this.roundWidth = roundWidth; } public boolean isTextShow() { return textShow; } public void setTextShow(boolean textShow) { this.textShow = textShow; } }文本matrics的分析图：
在我们中的布局：
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:gravity="center" tools:context="com.fly.lsn30_customprogressbar.MainActivity"> <com.fly.lsn30_customprogressbar.CustomProgressBar android:id="@+id/progressbar" android:layout_width="100dp" android:layout_height="100dp" app:roundProgressColor="#ff00ff" app:roundWidth="15dp" app:textColor="#ffff00" app:textSize="20dp" /> </LinearLayout>在MainActivity中使用： import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; public class MainActivity extends AppCompatActivity { private CustomProgressBar progressbar; private int progress = 0; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); progressbar = (CustomProgressBar) findViewById(R.id.progressbar); progressbar.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { new Thread(new Runnable() { @Override public void run() { while (progress <= 100) { progress += 2; progressbar.setProgress(progress); try { Thread.sleep(100); } catch (InterruptedException e) { e.printStackTrace(); } } } }).start(); } }); } }------------------大家可以自己试着自己再封装完善一下-----------------
