我有一些代码，在位图（画布）上绘制文本
canvas.drawTextOnPath(Text, textPath[count], gipa, -10, text);
请问，在使用路径（textPath）绘制文本时，是否可以设置背景颜色？
这是用于仅绘制文本的完整函数。
public void drawText(float x,float y ,String Text,Canvas canvas,Paint paint1 ,int count )
{
float xren =text.measureText(Text.trim());
canvas.drawTextOnPath(Text, textPath[count], gipa, -10, text);
}
使用这个函数我可以在我的画布上绘制文本。那么如何修改这个函数以便用背景来绘制这段文本呢？
这里可能需要两个步骤。首先，您需要使用背景颜色绘制路径线，并设置一个画笔对象的线条粗度。然后再按指示绘制文本。同样，更改画笔的样式可以帮助达到所需效果。尝试使用FILL、STROKE或FILL_AND_STROKE来获得不同的效果。
mpaint.setStyle(Paint.Style.STROKE);
mpaint.setStrokeWidth(strokeWidth);
添加了一个样例，用红色绘制一个路径(矩形)：
Paint mPaint = new Paint();
mPaint.setColor(Color.RED);
Path mPath = new Path();
RectF mRectF = new RectF(20, 20, 240, 240);
mPath.addRect(mRectF, Path.Direction.CCW);
mPaint.setStrokeWidth(20);
mPaint.setStyle(Paint.Style.STROKE);
canvas.drawPath(mPath, mPaint);
然后沿着相同的路径绘制文本（蓝色）：
mPaint.setColor(Color.BLUE);
mPaint.setStrokeWidth(0);
mPaint.setStyle(Paint.Style.FILL);
mPaint.setTextSize(20);
canvas.drawTextOnPath("Draw the text, with origin at (x,y), using the specified paint, along the specified path.", mPath, 0, 5, mPaint);
如果你想要像这样做，请实现下面的代码片段：
/**
* PUT THIS METHOD FOR IMPLEMENT WATER-MARK IN COMMON FILE
*/
public static Bitmap waterMark(Bitmap src, String watermark) {
//get source image width and height
int w = src.getWidth();
int h = src.getHeight();
Bitmap result = Bitmap.createBitmap(w, h, src.getConfig());
Canvas canvas = new Canvas(result);
canvas.drawBitmap(src, 0, 0, null);
Paint paint = new Paint();
Paint.FontMetrics fm = new Paint.FontMetrics();
paint.setColor(Color.WHITE);
paint.getFontMetrics(fm);
int margin = 5;
canvas.drawRect(50 - margin, 50 + fm.top - margin,
50 + paint.measureText(watermark) + margin, 50 + fm.bottom
+ margin, paint);
paint.setColor(Color.RED);
canvas.drawText(watermark, 50, 50, paint);
return result;
}
//获取URI中的位图：
private Bitmap getBitmapFromUri(String photoPath) {
Bitmap image = null;
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap bitmap = BitmapFactory.decodeFile(photoPath, options);
return bitmap;
}
// 保存图片：
private String SaveImage(Bitmap finalBitmap) {
String root = Environment.getExternalStorageDirectory().toString();
File myDir = new File(root + "/shareImage");
myDir.mkdirs();
Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
String fname = "Image" + n + ".jpg";
File file = new File(myDir, fname);
if (file.exists()) file.delete();
try {
FileOutputStream out = new FileOutputStream(file);
finalBitmap.compress(Bitmap.CompressFormat.JPEG, 20, out);
out.flush();
out.close();
} catch (Exception e) {
e.printStackTrace();
}
return file.getAbsolutePath();
}
// 像这样调用：
Bitmap bitmap = getBitmapFromUri(attachment.get(i).getPath()); // Enter here your Image path
Bitmap bitmapp = waterMark(bitmap, "ENTER YOUR TEXT FOR WATERMARK LABEL");
String path = SaveImage(bitmapp);
Uri uri = Uri.fromFile(new File(path));
现在，您可以从URI中获取新实现的水印图像了。
希望这能帮到您。
我认为这种解决方案比drawPath更好，更灵活。
使用此方法计算文本背景的大小：
private @NonNull Rect getTextBackgroundSize(float x, float y, @NonNull String text, @NonNull TextPaint paint) {
Paint.FontMetrics fontMetrics = paint.getFontMetrics();
float halfTextLength = paint.measureText(text) / 2 + 5;
return new Rect((int) (x - halfTextLength), (int) (y + fontMetrics.top), (int) (x + halfTextLength), (int) (y + fontMetrics.bottom));
}
然后以Rect的形式绘制背景：
Rect background = getTextBackgroundSize(x, y, text, textPaint);
canvas.drawRect(background, bkgPaint);
canvas.drawText(text, x, t, textPaint);
我创建了这个方法，它将让您更好地了解如何轻松完成这项任务。
public static Drawable getTextToDrawable(final String sText, final float textSize, final int textColor, final int bgColor, final int imageSize) {
Shape shape = new Shape() {
@Override
public void draw(Canvas canvas, Paint paint) {
paint.setTextSize(spToPixel(textSize));
int ivImageSize = SUtils.dpToPx(imageSize);
paint.setTextAlign(Paint.Align.LEFT);
float baseline = -paint.ascent(); // ascent() is negative
int width = (int) (paint.measureText(sText)); // round
int height = (int) (baseline + paint.descent());
Bitmap image = Bitmap.createBitmap(ivImageSize, (int) (ivImageSize), Bitmap.Config.ARGB_8888);
canvas.drawBitmap(image, ivImageSize, ivImageSize, paint);
paint.setColor(bgColor);
if (sText != null) {
if (sText.length() < 3) {
canvas.drawCircle(ivImageSize / 2, ivImageSize / 2, ivImageSize / 2, paint);
paint.setColor(textColor);
canvas.drawText(sText, (ivImageSize - width) / 2, (height+baseline)/2, paint);
} else {
canvas.drawRect(0, 0, ivImageSize, height, paint);
paint.setColor(textColor);
canvas.drawText(sText, (ivImageSize - width) / 2, baseline, paint);
}
}
}
};
return new ShapeDrawable(shape);
}