自定义view的Paint的梳理

画笔：确定绘制内容的具体效果

4.0以上建议关闭硬件加速

android:hardwareAccelerated="false"

基本属性

 Paint mPaint = new Paint();

 mPaint.reset();//重置paint

 mPaint.setColor(Color.BLUE);

 mPaint.setStyle(Paint.Style.FILL);//只填充，不描边
 mPaint.setStyle(Paint.Style.STROKE);//只描边，不填充
 mPaint.setStyle(Paint.Style.FILL_AND_STROKE);//描边和填充

 mPaint.setStrokeWidth(1.2f);//设置画笔的粗细

 mPaint.setStrokeWidth(10f);//设置画笔宽度为10px

 mPaint.getColor();//获得画笔颜色

 mPaint.setShader(new Shader());//设置着色器，绘制多彩图案

 mPaint.setARGB(100, 100, 100, 100);//设置画笔颜色

 mPaint.setAlpha(30);//设置透明度
 mPaint.getAlpha();//获得画笔透明度

 mPaint.setTextSize(10);//设置字体大小10px

 mPaint.setTextAlign(Paint.Align.LEFT);//设置左对齐
 mPaint.setTextAlign(Paint.Align.CENTER);//设置中间对齐
 mPaint.setTextAlign(Paint.Align.RIGHT);//设置右对齐

 mPaint.setUnderlineText(true);//设置文本下划线

 mPaint.setStrikeThruText(true);//设置删除线

 mPaint.setFakeBoldText(true);//设置文本粗体

 mPaint.setTextSkewX(-0.5f);//设置斜体

 mPaint.setShadowLayer(5, 5, 5, Color.YELLOW);//设置文字阴影

 mPaint.setAntiAlias(true);//设置抗锯齿

 mPaint.setStrokeCap(Paint.Cap.ROUND);//这只末端仙帽为圆形，即在绘制的图形两端添加半圆形
 mPaint.setStrokeCap(Paint.Cap.BUTT);//默认无线帽
 mPaint.setStrokeCap(Paint.Cap.SQUARE);//这只末端仙帽为方形，即在绘制的图形两端添加半圆形

 mPaint.setStrokeJoin(Paint.Join.BEVEL);//设置线段连接处样式为直线
 mPaint.setStrokeJoin(Paint.Join.MITER);//设置线段连接处样式为锐角
 mPaint.setStrokeJoin(Paint.Join.ROUND);//圆角

 mPaint.setStrokeMiter(30f);//设置画笔的倾斜度，实际并没什么卵用

 mPaint.setPathEffect(new CornerPathEffect(100));//设置连接点为半径100px的圆形接入


 mPaint.setTextSkewX(-0.3f);//这是字体倾斜度，默认右方向倾斜为-0.25

 mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.ADD));//设置多图案叠加方式
// case  0: return Mode.CLEAR;
// case  1: return Mode.SRC;
// case  2: return Mode.DST;
// case  3: return Mode.SRC_OVER;
// case  4: return Mode.DST_OVER;
// case  5: return Mode.SRC_IN;
// case  6: return Mode.DST_IN;
// case  7: return Mode.SRC_OUT;
// case  8: return Mode.DST_OUT;
// case  9: return Mode.SRC_ATOP;
// case 10: return Mode.DST_ATOP;
// case 11: return Mode.XOR;
// case 16: return Mode.DARKEN;
// case 17: return Mode.LIGHTEN;
// case 13: return Mode.MULTIPLY;
// case 14: return Mode.SCREEN;
// case 12: return Mode.ADD;
// case 15: return Mode.OVERLAY;

image

基本方法

        String s = "1231111111";

        float v = mPaint.measureText(s);//测量文本长度

        mPaint.measureText(s, 2, 5);//测量文本长度，开始以及结束的索引


        //通过外边距矩形获得内置文本宽高
        Rect rect = new Rect();
        mPaint.getTextBounds(s, 2, 6, rect);
        int width = rect.width();
        int height = rect.height();

       
        //获得精确字体宽度
        int arr = 0;
        int len = s.length();
        float[] floats = new float[len];
        mPaint.getTextWidths(s, floats);

        for (int i = 0; i < len; i++) {
            arr += (int) Math.ceil(floats[i]);
        }
        int widthText = arr;