android - 如何在 Android 中使用 Canvas 旋转文本

Question

我在 android 中使用 canvas 绘制饼图并使用下面的代码在该饼图的每个切片上绘制文本(在路径上绘制弧线)，现在我想绘制文本长度，即从中心到末端每个切片的，所以如何使用开始和扫描角度旋转圆弧。

p.addArc(mEventsRect, fStartAngle, fSweepAngle);
mBgPaints.setColor(iTextColor);
canvas.drawTextOnPath(sTextValue, p, fHOffSet, fVOffSet, mBgPaints);

Answer 1

你可以试试这个 fragment :(来自:http://www.helloandroid.com/tutorials/how-use-canvas-your-android-apps-part-2)

int x = 75;
int y = 185;
paint.setColor(Color.GRAY);
paint.setTextSize(25);
String rotatedtext = "Rotated helloandroid :)";

//Draw bounding rect before rotating text:

Rect rect = new Rect();
paint.getTextBounds(rotatedtext, 0, rotatedtext.length(), rect);
canvas.translate(x, y);
paint.setStyle(Paint.Style.FILL);

canvas.drawText(rotatedtext , 0, 0, paint);
paint.setStyle(Paint.Style.STROKE);
canvas.drawRect(rect, paint);

canvas.translate(-x, -y);


paint.setColor(Color.RED);
canvas.rotate(-45, x + rect.exactCenterX(),y + rect.exactCenterY());
paint.setStyle(Paint.Style.FILL);
canvas.drawText(rotatedtext, x, y, paint);