畫筆：確定繪制內容的具體效果

4.0以上建議關閉硬件加速

android:hardwareAccelerated="false"

基本屬性

 Paint mPaint = new Paint();

 mPaint.reset();//重置paint

 mPaint.setColor(Color.BLUE);

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

 mPaint.setStrokeWidth(1.2f);//設置畫筆的粗細

 mPaint.setStrokeWidth(10f);//設置畫筆寬度為10px

 mPaint.getColor();//獲得畫筆顏色

 mPaint.setShader(new Shader());//設置著色器，繪制多彩圖案

 mPaint.setARGB(100, 100, 100, 100);//設置畫筆顏色

 mPaint.setAlpha(30);//設置透明度
 mPaint.getAlpha();//獲得畫筆透明度

 mPaint.setTextSize(10);//設置字體大小10px

 mPaint.setTextAlign(Paint.Align.LEFT);//設置左對齊
 mPaint.setTextAlign(Paint.Align.CENTER);//設置中間對齊
 mPaint.setTextAlign(Paint.Align.RIGHT);//設置右對齊

 mPaint.setUnderlineText(true);//設置文本下劃線

 mPaint.setStrikeThruText(true);//設置刪除線

 mPaint.setFakeBoldText(true);//設置文本粗體

 mPaint.setTextSkewX(-0.5f);//設置斜體

 mPaint.setShadowLayer(5, 5, 5, Color.YELLOW);//設置文字陰影

 mPaint.setAntiAlias(true);//設置抗鋸齒

 mPaint.setStrokeCap(Paint.Cap.ROUND);//這只末端仙帽為圓形，即在繪制的圖形兩端添加半圓形
 mPaint.setStrokeCap(Paint.Cap.BUTT);//默認無線帽
 mPaint.setStrokeCap(Paint.Cap.SQUARE);//這只末端仙帽為方形，即在繪制的圖形兩端添加半圓形

 mPaint.setStrokeJoin(Paint.Join.BEVEL);//設置線段連接處樣式為直線
 mPaint.setStrokeJoin(Paint.Join.MITER);//設置線段連接處樣式為銳角
 mPaint.setStrokeJoin(Paint.Join.ROUND);//圓角

 mPaint.setStrokeMiter(30f);//設置畫筆的傾斜度，實際并沒什么卵用

 mPaint.setPathEffect(new CornerPathEffect(100));//設置連接點為半徑100px的圓形接入


 mPaint.setTextSkewX(-0.3f);//這是字體傾斜度，默認右方向傾斜為-0.25

 mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.ADD));//設置多圖案疊加方式
// 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);//測量文本長度

        mPaint.measureText(s, 2, 5);//測量文本長度，開始以及結束的索引


        //通過外邊距矩形獲得內置文本寬高
        Rect rect = new Rect();
        mPaint.getTextBounds(s, 2, 6, rect);
        int width = rect.width();
        int height = rect.height();

       
        //獲得精確字體寬度
        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;