借鉴ImageView的一条线毕加索集 [英] Draw a line on ImageView set by Picasso

问题描述

我试图找出如何简单地画一条线，在毕加索被设置在图像上。我发现，如果我只是设置图像，给定一个URI，与毕加索并尝试使用以下绘制油漆它：

I am trying to figure out how to simply draw a line on an image that is being set in Picasso. I found that if I simply set the image, given a URI, with Picasso and try to draw paint to it using the following:

canvas = new Canvas(bitmap);
image.draw(canvas);
topEdge = new Paint();
topEdge.setColor(context.getResources().getColor(R.color.blue));
topEdge.setStrokeWidth(5);
canvas.drawLine(c1.getX(), c1.getY(), c2.getX(), c2.getY(), topEdge);

然后我得到一个崩溃说，位图必须是可变的第一位。所以我说这上面code：

Then I get a crash saying that the bitmap needs to be mutable first. So I added this above that code:

Bitmap workingBitmap = ((BitmapDrawable) image.getDrawable()).getBitmap();
Bitmap mutableBitmap = workingBitmap.copy(Bitmap.Config.ARGB_8888, true);

，然后创建新的Canvas（mutableBitmap），而不是在画布上。这样取出的崩溃，但是什么都没有绘制。我相信这是因为我的毕加索之前设置的图像，所以现在我需要用这种新的可变位复位毕加索。问题是这样的code是在的onSuccess（）回调毕加索。我能做些什么，以允许通过毕加索的图像上绘制的画？

And then create the canvas with new Canvas(mutableBitmap) instead. This removed the crash, however nothing is being drawn. I believe this is because my Picasso is setting the image before, so now I need to reset Picasso with this new mutable bitmap. The problem is this code is in the onSuccess() callback for Picasso. What can I do to allow Paint to be drawn on an image through Picasso?

推荐答案

只需按照以下步骤操作：

just follow the steps below:

1. 编写您自己的类扩展了类转型象下面这样：

1. Write your own class extends the class Transformation like below:

 class DrawLineTransformation implements Transformation {

  @Override
  public String key() {
    // TODO Auto-generated method stub
    return "drawline";
  }

  @Override
  public Bitmap transform(Bitmap bitmap) {
    // TODO Auto-generated method stub
    synchronized (DrawLineTransformation.class) {
      if(bitmap == null) {
        return null;
      }
      Bitmap resultBitmap = bitmap.copy(bitmap.getConfig(), true);
      Canvas canvas = new Canvas(resultBitmap);
      Paint paint = new Paint();
      paint.setColor(Color.BLUE);
      paint.setStrokeWidth(10);
      canvas.drawLine(0, resultBitmap.getHeight()/2, resultBitmap.getWidth(), resultBitmap.getHeight()/2, paint);
      bitmap.recycle();
      return resultBitmap;
    }
  }
}

2，添加），以RequestCreator与Picasso.load（创建的转换功能，如下图所示：

2、Add the Transformation to RequestCreator created with Picasso.load() function like below:

Picasso picasso = Picasso.with(getApplicationContext());
DrawLineTransformation myTransformation = new DrawLineTransformation();
picasso.load("http://www.baidu.com/img/bdlogo.png").transform(myTransformation).into(imageview);

这就是你需要做的所有步骤，只是享受！

That's all steps you need to do , just enjoy!

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