android 自定义仪表盘

新建Class继承view
2.新建xml文件，设置控件属性

`<resources>
    <declare-styleable name="Flwp">
        <attr name="outcolor" format="color"></attr>
        <attr name="intcolor" format="color"></attr>
        <attr name="border_width" format="dimension"></attr>
        <attr name="step_text" format="dimension"></attr>
        <attr name="text_color" format="color"></attr>
        <attr name="step_size" format="dimension"></attr>
    </declare-styleable>
</resources>`

引用属性

 TypedArray array= context.obtainStyledAttributes(attrs,R.styleable.Flwp);
        moutcolor=array.getColor(R.styleable.Flwp_outcolor,moutcolor);
        minnercolor=array.getColor(R.styleable.Flwp_intcolor,minnercolor);
        mbwidth= (int) array.getDimension(R.styleable.Flwp_border_width,mbwidth);
        mtcolor=array.getColor(R.styleable.Flwp_text_color,mtcolor);
        mtext= (int) array.getDimension(R.styleable.Flwp_step_text,0);
        mSize=array.getDimensionPixelSize(R.styleable.Flwp_step_size,mSize);
        array.recycle();//使用结束后回收

设置框体

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    
    
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    int width=MeasureSpec.getSize(widthMeasureSpec);
    int height=MeasureSpec.getSize(heightMeasureSpec);
    setMeasuredDimension(width<height?width:height,width<height?width:height);
}

重绘

        int center=getWidth()/2;
        int radios=(getWidth()-mbwidth)/2;
        RectF rectF=new RectF(mbwidth/2,mbwidth/2,center+radios,center+radios);
        canvas.drawArc(rectF,135,275,false,mpaint);
       float wight=(float)mtext/mj;
        canvas.drawArc(rectF,135,(float)275*wight,false,mpaint_2);
        String mcontext=mtext+"°";
        Rect rec=new Rect();
        mtextpaint.getTextBounds(mcontext,0,mcontext.length(),rec);
        int dx=getWidth()/2-rec.width()/2;
        Paint.FontMetricsInt fontMetricsInt=mtextpaint.getFontMetricsInt();
        int dy=fontMetricsInt.bottom-fontMetricsInt.top;
        int baseLine=getHeight()/2+dy/2;
        canvas.drawText(mcontext,dx,baseLine,mtextpaint);
    }