Android 上的间歇性 HttpClient GET 问题

发布于 2024-10-07 21:37:32 字数 1993 浏览 7 评论 0原文

我有一个android应用程序，我一直在开发它从服务器下载图像，将其读入位图并将其显示在ImageView上，

这在大多数情况下都很好用，但每隔一段时间，它就会经历这个过程（有一个 ProgressDialog 说“正在获取图像...”），一旦完成，就不会显示任何内容。 logcat 中似乎没有任何与此相关的内容。

代码如下：

    Bitmap image = null;

    HttpClient client = new DefaultHttpClient();
    HttpGet get = new HttpGet(webService + "?cmd=get");

    try
    {
        HttpResponse resp = client.execute(get);

        Log.i("PhotoRouletteDebug", "Resp buffer size: " + (int)resp.getEntity().getContentLength());
        InputStream is = resp.getEntity().getContent();

        BufferedInputStream buf = new BufferedInputStream(is, (int)resp.getEntity().getContentLength());

        image = BitmapFactory.decodeStream(buf);

        // clean up
        buf.close();
        is.close();

即使没有显示任何内容，Resp 内容长度也始终报告正确的大小，但最终仍然没有显示任何内容。

此代码是从 AsyncTask 调用的，但一次仅调用 1 个任务。

这让我发疯，我不知道为什么它一直这样做。

编辑：这是设置 imageView 的代码

// AsyncTask for Getting a new image from the queue
protected class GetImageTask extends AsyncTask<String, String, Bitmap>
{
    protected void onPreExecute()
    {
        // lets show a progress dialog so the user knows something is going on
        progressDialog = ProgressDialog.show(PhotoRoulette.this, "", "Fetching image...", true);
    }

    protected void onPostExecute (Bitmap image)
    {
        // we got a new photo so lets display it where it needs to be displayed
        try
        {
            photoView = (ImageView)findViewById(R.id.photoView);
            photoView.setImageBitmap(image);
        }
        catch (Exception e)
        {
            Log.e("Debug", "Something absolutely retarded happened", e);
        }

        // hide the progress dialog - we're all done
        progressDialog.dismiss();
    }

    protected Bitmap doInBackground(String... urls)
    {
        // Get a new Bitmap Queue Image
        Bitmap image = imageHandler.getQueueImage();
        return image;
    }
}

原文

I have an android application i have been working on that downloads an image from a server, reads it into a bitmap and displays it on an ImageView

This works great most of the time, but every so often, it goes through the process (There is a ProgressDialog saying "Fetching image...") and once its done nothing gets displayed. There has not been anything in logcat that even seems to remotely relate to this.

Here is the code:

    Bitmap image = null;

    HttpClient client = new DefaultHttpClient();
    HttpGet get = new HttpGet(webService + "?cmd=get");

    try
    {
        HttpResponse resp = client.execute(get);

        Log.i("PhotoRouletteDebug", "Resp buffer size: " + (int)resp.getEntity().getContentLength());
        InputStream is = resp.getEntity().getContent();

        BufferedInputStream buf = new BufferedInputStream(is, (int)resp.getEntity().getContentLength());

        image = BitmapFactory.decodeStream(buf);

        // clean up
        buf.close();
        is.close();

Even when nothing is getting displayed, the Resp content length always reports a correct size but still, nothing ends up getting displayed.

This code is called from an AsyncTask, but only 1 task is ever called at a time.

This is driving me insane, i have no idea why its keeps doing this.

Edit: Here is the code that sets the imageView

// AsyncTask for Getting a new image from the queue
protected class GetImageTask extends AsyncTask<String, String, Bitmap>
{
    protected void onPreExecute()
    {
        // lets show a progress dialog so the user knows something is going on
        progressDialog = ProgressDialog.show(PhotoRoulette.this, "", "Fetching image...", true);
    }

    protected void onPostExecute (Bitmap image)
    {
        // we got a new photo so lets display it where it needs to be displayed
        try
        {
            photoView = (ImageView)findViewById(R.id.photoView);
            photoView.setImageBitmap(image);
        }
        catch (Exception e)
        {
            Log.e("Debug", "Something absolutely retarded happened", e);
        }

        // hide the progress dialog - we're all done
        progressDialog.dismiss();
    }

    protected Bitmap doInBackground(String... urls)
    {
        // Get a new Bitmap Queue Image
        Bitmap image = imageHandler.getQueueImage();
        return image;
    }
}

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遇见了你 2024-10-14 21:37:32

您没有向我们展示用于显示图像的代码，因此我们不确定该代码是否正确。或许问题就出在那里？

但假设问题是图像已损坏，我将开始调试此问题：用 PushbackInputStream。从buf中读取字节并将其保存到文件中；然后将这些相同的字节推回到 PushbackInputStream 中。然后将 PushbackInputStream 传递到 BitmapFactory.decodeStream 中。如果图像成功显示，则删除该文件（手动或以编程方式）。否则，您现在可以随意检查位图。