节约位图绘制在画布上 [英] Saving Bitmap drawn on Canvas

问题描述

在我的应用程序扩展了ImageView的和重写它的onDraw（）方法。我使用的是彩色滤光片操纵位图添加像倒置，灰度ETCC一定的影响。绘制位图后，我试图挽救它，但我只能够保存原始位没有增加的影响。下面是的onDraw（在code）及保存方法：结果

In my application I extended the ImageView and overriden its onDraw() method. I am using a color filter to manipulate the bitmap for adding some effects like invert, grayscale etcc. After drawing the bitmap I am trying to save it but I am only able to save the original bitmap with no added effects. Here is the code for onDraw() and save method:

protected void onDraw(Canvas canvas)
{
    Paint paint = mPaint;
    //cmf is the color matrix filter
    paint.setColorFilter(cmf);

    if(mBitmap != null)
    {
        canvas.drawBitmap(mBitmap, offsetW, offsetH, paint);
    }
}

code保存位图：结果

code for saving the bitmap:

 try
        {
            FileOutputStream fout = new FileOutputStream(path);

            mBitmap.compress(CompressFormat.JPEG, 100, fout);
        } catch (FileNotFoundException e)
        {
            e.printStackTrace();
        }

我是不是做错了什么？任何帮助将AP pretiated。

Am I doing something wrong? Any help will be appretiated.

推荐答案

您的画显示的画布上，原始位不被改变。您应该创建一个新的位图和油漆就可以了。当彩色矩阵过滤器的更换做到这一点：

You are painting on the canvas that is displayed, original bitmap is not changed. You should create a new bitmap and paint on it. When color matrix filter changes do this:

Bitmap tmp = Bitmap.createBitmap(mBitmap.getWidth(), mBitmap.getHeight(), mBitmap.getConfig())
Canvas canvas = new Canvas(tmp)
cnvas.drawBitmap(tmp, 0, 0, paint);

然后，您可以使用此TMP位图绘制并保存它。

Then, you can use this tmp bitmap to draw it and save it.

而不是使用自定义的的ImageView 使用正常的，并设置其形象到这个新位图：

Instead of using customized ImageView use a normal one and set its image to this new bitmap:

imageView.setImageBitmap(tmp)

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