本节介绍自定义view-圆形进度条
思路：
根据前面介绍的自定义view内容可拓展得之；
1：新建类继承自View
2：添加自定义view属性
3：重写onDraw(Canvas canvas)
4：实现功能
下面上代码

1.自定义view代码：

public class CustomView extends View {//背景圆环颜色private int circleColor;//进度条颜色&字体颜色(为了美观，所以设计字体颜色和进度条颜色值一致)private int secondCircleColor;//进度条&背景圆环宽度private float stroke_width;//进度值private float progress;//总进度值，默认为100private float totalProgress;//字体大小private float textSize;//填充模式private int style_type;public CustomView(Context context) {super(context);}public CustomView(Context context, AttributeSet attrs) {super(context, attrs);TypedArray array=context.obtainStyledAttributes(attrs, R.styleable.CustomView);circleColor=array.getColor(R.styleable.CustomView_circleColor, Color.BLACK);secondCircleColor=array.getColor(R.styleable.CustomView_secondCircleColor, Color.RED);stroke_width=array.getDimension(R.styleable.CustomView_stroke_width, 2);progress=array.getFloat(R.styleable.CustomView_progress, 0);totalProgress=array.getFloat(R.styleable.CustomView_totalProgress, 100);textSize=array.getDimension(R.styleable.CustomView_textSize, 16);style_type=array.getInt(R.styleable.CustomView_style_Type, 0);}public CustomView(Context context, AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);}public void setCircleColor(int color){circleColor=color;}public int getCircleColor(){return circleColor;}public void setSecondCircleColor(int color){secondCircleColor=color;}public int getSecondColor(){return secondCircleColor;}public void setStrokeWidth(float width){stroke_width=width;}public float getStrokeWidth(){return stroke_width;}public void setProgress(float progress){this.progress=progress;postInvalidate();//刷新界面}public float getProgress(){return this.progress;}public void setTotalProgress(float totalProgress){this.totalProgress=totalProgress;}public float getTotalProgress(){return this.totalProgress;}public void setTextSize(float textSize){this.textSize=textSize;}public float getTextSize(){return this.textSize;}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);//第一进度圆final Paint paint_background=new Paint();paint_background.setAntiAlias(true);paint_background.setStrokeWidth(stroke_width);paint_background.setStyle(Style.STROKE);paint_background.setColor(circleColor);//第二进度圆final Paint paint_progress=new Paint();paint_progress.setAntiAlias(true);paint_progress.setStrokeWidth(stroke_width);if(style_type==0){paint_progress.setStyle(Style.STROKE);}else if(style_type==1){paint_progress.setStyle(Style.FILL_AND_STROKE);}paint_progress.setColor(secondCircleColor);//画textfinal Paint paint_text=new Paint();paint_text.setAntiAlias(true);if(style_type==0){paint_text.setColor(secondCircleColor);}else if(style_type==1){paint_text.setColor(circleColor);}paint_text.setTextSize(textSize);paint_text.setTextAlign(Align.CENTER);if(getWidth()!=getHeight()){throw new IllegalArgumentException("高度和宽度必须相等");//控制宽度和高度}else{RectF circle_background=new RectF();circle_background.left=getLeft()+stroke_width;circle_background.right=getRight()-stroke_width;circle_background.top=getTop()+stroke_width;circle_background.bottom=getBottom()-stroke_width;canvas.drawArc(circle_background, -90, 360, false, paint_background);RectF circle_progress=new RectF();circle_progress.left=getLeft()+stroke_width;circle_progress.right=getRight()-stroke_width;circle_progress.top=getTop()+stroke_width;circle_progress.bottom=getBottom()-stroke_width;if(progress>totalProgress){throw new IllegalArgumentException("当前进度值不能大于总进度值");}else{if(style_type==0){canvas.drawArc(circle_progress, -90, progress/totalProgress*360, false, paint_progress);}else if(style_type==1){canvas.drawArc(circle_progress, -90, progress/totalProgress*360, true, paint_progress);}}canvas.drawText((int)progress+"/"+(int)totalProgress, getLeft()+getWidth()/2, getTop()+getHeight()/2+textSize/4, paint_text);}}}

2：attr属性

<?xml version="1.0" encoding="utf-8"?>
<resources><!--declare-styleable:声明样式类型;attr name=""声明属性名;format="属性的类型"  --><declare-styleable name="CustomEditText"><attr name="lineColor" format="color" /><attr name="lineHeight" format="dimension"/></declare-styleable><declare-styleable name="CustomView"><attr name="stroke_width" format="dimension"/><attr name="circleColor" format="color"/><attr name="secondCircleColor" format="color"/><attr name="progress" format="float"/><attr name="totalProgress" format="float"/><attr name="textSize" format="dimension"/><attr name="style_Type"><enum name="stroke" value="0"/><enum name="stroke_and_fill" value="1"/></attr></declare-styleable></resources>

3：xml布局文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:layout_width="wrap_content"android:layout_height="wrap_content" ><com.anqiansong.views.CustomViewxmlns:circle="http://schemas.android.com/apk/res/com.anqiansong.androidcustomview"android:id="@+id/customview"android:layout_width="50dp"android:layout_height="50dp"android:layout_centerInParent="true"circle:circleColor="#000000"circle:secondCircleColor="#ff0000"circle:stroke_width="2dp"circle:totalProgress="100" circle:progress="10"circle:style_Type="stroke"/></RelativeLayout>

当xml文件中circle:style_Type="stroke"时

当xml文件中circle:style_Type="stroke_and_fill"时

4：activity中调用

public class MainActivity extends ActionBarActivity {CustomView customView;private float progress=0;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);customView=(CustomView) findViewById(R.id.customview);handler.sendEmptyMessageDelayed(0, 1000);}Handler handler=new Handler(){public void handleMessage(android.os.Message msg) {if(msg.what==0){if(progress>100){return;}else{customView.setProgress(progress);progress+=2;handler.sendEmptyMessageDelayed(0, 100);}}};};}