java.lang.RuntimeException: Canvas: 试图绘制过大

Question

我正在尝试将图像从 Web 服务器检索到我的应用程序中。但是，当我在应用程序中查看图像时，应用程序崩溃了。

这是代码：

class DownloadFileFromURL extends AsyncTask<String, String, String> {

    private String file_url=null;

    /**

     * Before starting background thread

     * Show Progress Bar Dialog

     * */

    @Override

    protected void onPreExecute() {

        super.onPreExecute();

        toggleProgress();

    }

    public boolean dir_exists(String dir_path)

    {

        boolean ret = false;

        File dir = new File(dir_path);

        if(dir.exists() && dir.isDirectory())

            ret = true;

        return ret;

    }

    /**

     * Downloading file in background thread

     * */

    @Override

    protected String doInBackground(String... f_url) {

        int count;

        try {

            URL url = new URL(f_url[0]);

            URLConnection conection = url.openConnection();

            conection.connect();

            // this will be useful so that you can show a tipical 0-100% progress bar

            int lenghtOfFile = conection.getContentLength();

            // download the file

            InputStream input = new BufferedInputStream(url.openStream(), 8192);

            String dir_path = Environment.getExternalStorageDirectory().toString() + getResources().getString(R.string.DownloadFolder);

            if (!dir_exists(dir_path)){

                File directory = new File(dir_path);

                if(directory.mkdirs()){

                    Log.v("dir","is created 1");

                }else{

                    Log.v("dir","not created 1");

                }

                if(directory.mkdir()){

                    Log.v("dir","is created 2");

                }else{

                    Log.v("dir","not created 2");

                }

            }else{

                Log.v("dir","is exist");

            }

Answer 1

根据设备的显示尺寸，在显示之前调整图像大小是一个很好的方法。试试这个：//->reduce size of bitmap for displaying on imageViewBitmap bmp = BitmapFactory.decodeFile(file.getPath());float RealWidth = bmp.getWidth();float RealHeight = bmp.getHeight();int NewWidth, NewHeight;if (imageView.getWidth() > imageView.getHeight()) {&nbsp; &nbsp; NewWidth = imageView.getWidth();&nbsp; &nbsp; NewHeight = (int) ((RealHeight * NewWidth) / RealWidth);} else {&nbsp; &nbsp; NewHeight = imageView.getHeight();&nbsp; &nbsp; NewWidth = (int) ((RealWidth * NewHeight) / RealHeight);}bmp = Bitmap.createScaledBitmap(bmp, NewWidth, NewHeight, false);imageView.setImageBitmap(bmp);

Answer 2

在将图片文件解码到内存中之前，最好先读取图片的大小并将其与手机的大小进行比较，然后缩小并最终解码。