Paint
要绘图,首先得调整画笔,待画笔调整好之后,再将图像绘制到画布Canvas上,
这样才可以显示在手机屏幕上。Android 中的画笔是
Paint类,Paint
中包含了很多方法对其属性进行设置,
主要方法如下:(没有全部列出,大家可以查看官方文档http://android.toolib.net/reference/android/graphics/Paint.html
)
1 canvas.drawColor(Color.GREEN); 2 3 Paint paint1 = new Paint(); 4 canvas.drawCircle(40, 30, 20, paint1); 5 6 //设置画笔无锯齿,默认有锯齿 7 paint1.setAntiAlias(true); 8 canvas.drawCircle(100, 30, 20, paint1); 9 10 //设置画笔的透明度 11 canvas.drawText("无透明度", 100, 70, new Paint()); 12 Paint paint2 = new Paint(); 13 paint2.setAlpha(0x77); 14 canvas.drawText("半透明度", 20, 70, paint2); 15 16 //设置绘制文本的锚点 17 canvas.drawText("锚点", 20, 90, new Paint()); 18 Paint paint3 = new Paint(); 19 20 //设置以文本的中心点绘制 21 paint3.setTextAlign(Paint.Align.CENTER); 22 canvas.drawText("锚点", 20, 105, paint3); 23 24 //获取文本的长度 25 Paint paint4 = new Paint(); 26 float len =paint4.measureText("文本宽度:"); 27 canvas.drawText("文本长度:"+len, 20, 130, new Paint()); 28 29 //设置画笔样式 30 canvas.drawRect(new Rect(20,140,40,160), new Paint()); 31 Paint paint5 = new Paint(); 32 33 //设置画笔不填充 34 paint5.setStyle(Style.STROKE); 35 canvas.drawRect(new Rect(60,140,80,160), paint5); 36 37 //设置画笔颜色 38 Paint paint6 = new Paint(); 39 paint6.setColor(Color.GRAY); 40 canvas.drawText("灰色", 30, 180, paint6); 41 42 //设置画笔的粗细程度 43 canvas.drawLine(20, 200,70, 200, new Paint()); 44 Paint paint7 = new Paint(); 45 paint7.setStrokeWidth(7); 46 canvas.drawLine(20, 220,70, 220,paint7); 47 48 //设置画笔绘制文本的字体粗细 49 Paint paint8 = new Paint(); 50 paint8.setTextSize(20); 51 canvas.drawText("文字尺寸", 20, 260, paint8); 52 53 //设置画笔的ARGB分量 ,a值 (透明度) 54 Paint paint9 = new Paint(); 55 paint9.setARGB(0x77, 0xff, 0x00, 0x00); 56 canvas.drawText("红色半透明", 20, 290, paint9);