自定义Progress进度条

自定义Progress进度条

先定义一个类继承View，实现构造函数(3个)，并重写onDraw()方法，定义画笔，开始画图。

重写onMeasure方法

1、边界参数——-widthMeasureSpec和heightMeasureSpec，效率的原因以整数的形式传入。在它们使用之前，首先要做的是使用MeasureSpec类的静态方法getMode和getSize来解释。

2、specMode有三种
MeasureSpec.EXACTLY —>边界已经确定，match_parent,fill_parent,50dp
MeasureSpec.AT_MOST—->父控件能给的最大尺寸，这样子View会根据这个上限来设置自己的尺寸，wrap_content.
MeasureSpec.UNSPECIFIED –>未指定大小，可以是任意大小。这种情况不多，一般都是父控件是AdapterView，通过measure方法传入的模式。

3、setMesauredDimension()，这个方法必须由onMeasure(int,int)来调用，来存储测量的宽，高值，如果是含有子view的还要调用measureChildren()

在values文件夹下定义一个attrs.xml，自定义属性

    <?xml version="1.0" encoding="utf-8"?>    <resources>        <declare-styleable name="CustomView">            <attr name="radius" format="dimension"/>            <attr name="stroke_width" format="dimension"/>            <attr name="back_circle_color" format="color"/>            <attr name="front_circle_color" format="color"/>            <attr name="text_visibility" format="boolean"/>        </declare-styleable>    </resources>

在activity_main中声明命名空间及使用自定义属性

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    xmlns:attrs="http://schemas.android.com/apk/res-auto"    android:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="@android:color/black"    tools:context="com.xht.android.customerview.MainActivity">    <com.xht.android.customerview.CustomView        android:id="@+id/custom"        android:layout_width="match_parent"        android:layout_height="match_parent"        attrs:radius="80dp"        attrs:stroke_width="15dp"        /></RelativeLayout>

自定义Progress的主代码编写

    /**     * Created by Administrator on 2016-10-18.     *     *  自定义一个进度条     */    public class CustomView extends View {        private static final int DEFAULT_RADIUS = 200;        private float mRadius=200;//园的半径        private float mStrokeWidth=50;//环的宽度        private float mStrokeHalf=mStrokeWidth/2;        private float mX=200+mStrokeHalf;        private float mY=200+mStrokeHalf;//x、y坐标-----控制图形的中心点        private Paint mPaintBackCirle;//背景白色圆环画笔        private Paint mPaintFromCirle;//前景绿色扇形圆环画笔        private Paint mPaintText;//进度的字体画笔        private RectF mRectf;        private int progress=0;        private int mTargetProgress=70;        private int maxProgress=100;        private int mWidth;//屏幕宽高        private int mHeight;        public CustomView(Context context) {            this(context,null);        }        public CustomView(Context context, AttributeSet attrs) {            this(context, attrs,0);        }        public CustomView(Context context, AttributeSet attrs, int defStyleAttr) {            super(context, attrs, defStyleAttr);            if (attrs!=null){                //获取半径和环形宽度等                TypedArray array=context.obtainStyledAttributes(attrs,R.styleable.CustomView);                mRadius=array.getDimensionPixelSize(R.styleable.CustomView_radius,DEFAULT_RADIUS);                mStrokeWidth=array.getDimensionPixelSize(R.styleable.CustomView_stroke_width,DEFAULT_RADIUS);                array.recycle();            }                init();        }        private void init() {            mPaintBackCirle=new Paint();            mPaintBackCirle.setAntiAlias(true);            mPaintBackCirle.setColor(Color.WHITE);            mPaintBackCirle.setStrokeWidth(mStrokeWidth);            mPaintBackCirle.setStyle(Paint.Style.STROKE);            mPaintFromCirle=new Paint();//画笔            mPaintFromCirle.setAntiAlias(true);            mPaintFromCirle.setColor(Color.BLUE);//颜色            mPaintFromCirle.setStrokeWidth(mStrokeWidth);//环的宽度            mPaintFromCirle.setStyle(Paint.Style.STROKE);//环            mPaintText=new Paint();//画笔            mPaintText.setAntiAlias(true);            mPaintText.setColor(Color.WHITE);//颜色            mPaintText.setTextSize(80);//设置字体大小            mPaintText.setTextAlign(Paint.Align.CENTER);//设置到中心          //  mRectf = new RectF(mStrokeHalf,mStrokeHalf,mRadius*2+mStrokeHalf,mRadius*2+mStrokeHalf);        }        @Override        protected void onDraw(Canvas canvas) {            //super.onDraw(canvas);            initRectF();            float angle=progress/(float)maxProgress*360;//转换成角度            canvas.drawCircle(mWidth/2,mHeight/2,mRadius,mPaintBackCirle);//画圆            canvas.drawArc(mRectf,-90,angle,false,mPaintFromCirle);            canvas.drawText(progress+"%",mWidth/2,mHeight/2,mPaintText);            if (progress<maxProgress){                progress+=2;                //强制绘制                invalidate();            }        }        //画矩形        private void initRectF(){            if (mRectf==null){                mRectf=new RectF();                int viewSize= (int) (mRadius*2);                int left=(mWidth-viewSize)/2;                int top=(mHeight-viewSize)/2;                int right=left+viewSize;                int buttom=top+viewSize;                mRectf.set(left,top,right,buttom);            }        }        @Override        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {            super.onMeasure(widthMeasureSpec, heightMeasureSpec);            mWidth = getRealSize(widthMeasureSpec);//获取屏幕宽            mHeight = getRealSize(heightMeasureSpec);//获取屏幕高            setMeasuredDimension(mWidth,mHeight);        }        public int getRealSize(int measureSpec){            int result=-1;            int mode=MeasureSpec.getMode(measureSpec);//模式            int size=MeasureSpec.getSize(measureSpec);//尺寸            if (mode==MeasureSpec.AT_MOST||mode==MeasureSpec.UNSPECIFIED){                //自己计算                result= (int) (mRadius*2+mStrokeWidth);            }else{                result=size;            }            return result;        }    }//插入图片