如何在 android 中拍摄的照片中添加时间戳

Question

@Override

protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    if (requestCode == CAMERA_REQUEST && resultCode == Activity.RESULT_OK) {

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String dateTime = sdf.format(Calendar.getInstance().getTime());
        Bundle extras = data.getExtras();
        Bitmap src= (Bitmap) extras.get("data");
        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);
        canvas.drawText(dateTime , 0, 0, null);
        click_image_id.setImageBitmap(result);
    }
}

它会崩溃，如果我更改并评论 canvas 实现，例如 //

Bundle extras = data.getExtras();

Bitmap src= (Bitmap) extras.get("data");

click_image_id.setImageBitmap(src);

它执行视图，但我需要图像中的时间戳，需要专家帮助

Answer 1

您的问题是您需要 drawText() 需要的 Paint 对象，它不能为空。这里的代码将解决您的 NPE。

编辑：

第二个问题是绘制文本的位置，复制并粘贴此解决方案。它会在左下角放置一个带有日期的黑色文本。

如果要自定义文本，请自定义Paint对象。我检查了这段代码，它工作正常。

@Override

protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    if (requestCode == CAMERA_REQUEST && resultCode == Activity.RESULT_OK) {

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String dateTime = sdf.format(Calendar.getInstance().getTime());
        Bundle extras = data.getExtras();
        Bitmap src= (Bitmap) extras.get("data");
        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);
        canvas.drawText(dateTime , 0, h, new Paint());
        click_image_id.setImageBitmap(result);
    }
}

Answer 2

您需要创建和配置一个 Paint 对象并在 canvas.drawText() 中使用它。尝试这样的事情（摘自 this 文章）。


private fun drawTextToBitmap(bitmap: Bitmap, textSize: Int = 78, text: String): Bitmap {

    val canvas = Canvas(bitmap)
    
    // new antialised Paint - empty constructor does also work
    val paint = Paint(Paint.ANTI_ALIAS_FLAG)
    paint.color = Color.BLACK
    
    // text size in pixels
    val scale = resources.displayMetrics.density
    paint.textSize = (textSize * scale).roundToInt().toFloat()

    //custom fonts or a default font
    val fontFace = ResourcesCompat.getFont(context, R.font.acrobat)
    paint.typeface = Typeface.create(fontFace, Typeface.NORMAL)


    // draw text to the Canvas center
    val bounds = Rect()
    //draw the text
    paint.getTextBounds(text, 0, text.length, bounds)

    //x and y defines the position of the text, starting in the top left corner
    canvas.drawText(text, x, y, paint)
    return bitmap
}

Answer 3

最后这段代码可以正常工作了感谢@ASP 和@BogdonAndroid

我检查了 solution

public static Bitmap mark(Bitmap src, boolean underline) {

    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    String dateTime = sdf.format(Calendar.getInstance().getTime());
    int w = src.getWidth();
    int h = src.getHeight();
    Bitmap result = Bitmap.createBitmap(w, h, src.getConfig());
    Canvas canvas = new Canvas(result);
    Paint tPaint = new Paint();
    tPaint.setTextSize(15);
    tPaint.setColor(Color.BLUE);
    tPaint.setStyle(Paint.Style.FILL);
    float height = tPaint.measureText("yY");
    canvas.drawBitmap(src,0,0,null);
    canvas.drawText(dateTime, 20f, height+15f, tPaint);
    return result;}

如何在 android 中拍摄的照片中添加时间戳

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