Question

我当前的代码成功上传了图片，但仍未显示显示Image uploaded successfully的Toast消息。如何在成功上传图像后显示Toast消息？

这是我的代码

 public void onClick(View v) {
                        dialog = ProgressDialog.show(Camera.this, "", "Uploading file...", true);
                        new Thread() {
                            public void run() {
                                try {
                                    //Toast.makeText(getBaseContext(), "File is uploading...", Toast.LENGTH_LONG).show();
                                    if(imageUpload(globalUID, largeImagePath)) {
                                         Toast.makeText(getApplicationContext(), "Image uploaded", Toast.LENGTH_LONG).show();
                                     } else {
                                         Toast.makeText(getApplicationContext(), "Error uploading image", Toast.LENGTH_LONG).show();
                                     }
                                } catch (Exception e) {

                                }

                            }
                        }.start();

这里是imageUpload方法

public boolean imageUpload(String uid, String imagepath) {
    boolean success = false;
    //Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
    Bitmap bitmapOrg = BitmapFactory.decodeFile(imagepath);
    ByteArrayOutputStream bao = new ByteArrayOutputStream();
    bitmapOrg.compress(Bitmap.CompressFormat.JPEG, 90, bao);

    byte [] ba = bao.toByteArray();
    String ba1=Base64.encodeToString(ba, 0);

    ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
    nameValuePairs.add(new BasicNameValuePair("image",ba1));
    nameValuePairs.add(new BasicNameValuePair("uid", uid));

    try {
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://www.example.info/androidfileupload/index.php");
        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
        HttpResponse response = httpclient.execute(httppost);
        HttpEntity entity = response.getEntity();
        if(response != null) {
            Toast.makeText(getApplicationContext(), "File uploaded successfully", Toast.LENGTH_LONG).show();
            success = true;
        }
        is = entity.getContent();
    } catch(Exception e) {
        Log.e("log_tag", "Error in http connection "+e.toString());
    }
    dialog.dismiss();
    return success;
}

Answer 1

您正尝试在非UI线程中显示Toast，因此无法看到Toast

完成任务后使用Handler以显示Toast.its，以便更好地使用AsyncTask.

使用AsyncTask，添加imageUpload code in DoinBackground(...) method and return boolean to onPostExxecute(),and You can display Toast in OnPostExecute Method.

Answer 2

我建议你在android中实现{{3>}，这就是所谓的无痛线程。

在你的情况下，你可以在doInBackground()方法中调用imageUpload（），从onPostExecute()方法显示Toast，不需要关心线程。

Answer 3

我不知道这是对还是错。你可以这样试试 -

public void onClick(View v)
{
    ProgressDialog dialog = ProgressDialog.show(DummyUsageActivity.this, "", "Uploading file...", true);
    this.runOnUiThread(new Runnable() {
        public void run() {
            try {
                //Toast.makeText(getBaseContext(), "File is uploading...", Toast.LENGTH_LONG).show();
                if(imageUpload(globalUID, largeImagePath)) {
                     Toast.makeText(DummyUsageActivity.this, "Image uploaded", Toast.LENGTH_LONG).show();
                 } else {
                     Toast.makeText(DummyUsageActivity.this, "Error uploading image", Toast.LENGTH_LONG).show();
                 }
            } catch (Exception e) {

            }
        }
    });
}

我认为这会奏效。根据用户 - Paresh Mayani＆amp; Samir Mangroliya对AsyncTask的建议也更好。

成功上传图像后不显示Toast消息

3 个答案: