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

这里写图片描述