Android的结合许多位图一个大单出现问题，不能循环使用位图 [英] Android Combine many bitmaps to one large one goes wrong and can't recycle bitmap

问题描述

我想结合中所包含的ArrayList中一个大的位图许多小位图。

不过，我不知道为什么大的位图的循环。这意味着它似乎复制阵列中的第一个元素。我试图绘制每个小位图阵列中进行测试，它工作正常，但是当我运行，如跌破code中的循环，它出了问题。

在addiditon，当我添加了 bmp.recycle（）和 BMP = NULL ，它会导致错误试图用一个循环位图。我不明白为什么错误发生。

你能帮助我，请，谢谢！

 公共静态位图getBitmapForVisibleRegion（的WebView的WebView）{
        位图returnedBitmap = NULL;
        webview.setDrawingCacheEnabled（真正的）;
        returnedBitmap = Bitmap.createBitmap（webview.getDrawingCache（））;
        webview.setDrawingCacheEnabled（假）;
        返回returnedBitmap;
    }


公共无效CombineBitmap（）{
    ArrayList的＆LT;位图＆GT;骨形态发生蛋白=新的ArrayList＆LT;位图＆GT;（）;
    的for（int i = 0; I＆LT; webView.getWidth; I + = needToCapture）{
    bmps.add（getBitmapForVisibleRegion（web视图））;
    webView.scrollBy（needToCapture，0）;

    }

            位图bigbitmap = Bitmap.createBitmap（largeBitmapWidth，largeBitmapHeight，Bitmap.Config.ARGB_8888）;
            帆布bigcanvas =新的Canvas（bigbitmap）;

            涂料粉刷=新的油漆（）;
            INT iWidth = 0;

            的for（int i = 0; I＆LT; bmps.size（）;我++）{
                BMP位= bmps.get（我）;
                bigcanvas.drawBitmap（BMP，iWidth，0，漆）;
                iWidth + = bmp.getWidth（）;

                bmp.recycle（）;
                BMP = NULL;
            }
}
 

解决方案

我终于找到了我的问题。这是因为我的伪错误。

我要使用scrollTo而不是scrollBy

在我改变scrollTo，一切工作正常。这实在是一个有益的经验。

I want to combine many small bitmaps which are contained in ArrayList to one large bitmap.

However, I don't know why the large bitmap is looped. It means it seems to copy only the first element in the array. I tried to draw each small bitmap in the array to test and it works fine, but when I run the loop like the below code, it goes wrong.

In addiditon, when I add the bmp.recycle() and bmp = null, it causes the error "trying to use a recycled bitmap". I don't understand why the error happens.

Can you help me, please, thanks!

public static Bitmap getBitmapForVisibleRegion(WebView webview) {
        Bitmap returnedBitmap = null;
        webview.setDrawingCacheEnabled(true);
        returnedBitmap = Bitmap.createBitmap(webview.getDrawingCache());
        webview.setDrawingCacheEnabled(false);
        return returnedBitmap;
    }


public void CombineBitmap(){
    ArrayList<Bitmap> bmps = new ArrayList<Bitmap>();
    for (int i = 0; i < webView.getWidth; i+=needToCapture){
    bmps.add(getBitmapForVisibleRegion(webView));
    webView.scrollBy(needToCapture, 0);

    }

            Bitmap bigbitmap    = Bitmap.createBitmap(largeBitmapWidth, largeBitmapHeight, Bitmap.Config.ARGB_8888);
            Canvas bigcanvas    = new Canvas(bigbitmap);

            Paint paint = new Paint();
            int iWidth = 0;

            for (int i = 0; i < bmps.size(); i++) {
                Bitmap bmp = bmps.get(i);
                bigcanvas.drawBitmap(bmp, iWidth , 0, paint);
                iWidth +=bmp.getWidth();

                bmp.recycle();
                bmp=null;
            }
}

解决方案

I finally found out my problem. It's because of my dummy mistake.

I have to use scrollTo instead scrollBy

After I change to scrollTo, everything works fine. This is really an useful experience.

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