Question

我没有像我认为的那样成功地做到这一点，所以我会问专家。

我有一个链接到图像的十个URL的ArrayList。我想显示第一个URL 2秒，然后获取第二个URL并执行相同的操作直到结束。

这是我到目前为止的情况，我想也许我不会在postExecute中以最佳方式进行对话？：

 private class LiveView extends AsyncTask<String, Integer, ArrayList<String>> {
        ProgressDialog dialog;
        private volatile boolean running = true;

        @Override
        protected void onPreExecute() {
             dialog = ProgressDialog.show(
                        myView.this,
                        "Working",
                        "Info message . . .",
                        true,
                        true,
                        new DialogInterface.OnCancelListener(){

                            public void onCancel(DialogInterface dialog) {
                                cancel(true);                           
                            }
                        }
                );
            }

        @Override
        protected void onCancelled() {
              running = false;
        }

        @Override
        protected ArrayList<String> doInBackground(String... passed) {



            while (running) {

            //removed the code here that sends the request to to make this shorter the server but it works fine
            return responseFromServer.arrayListofURLs;           //list or URLs 

            }
            return null;
        }

        @Override
        protected void onPostExecute(ArrayList<String> listURLs) {      
            dialog.cancel();

            Dialog liveView = new Dialog(myView.this, R.style.Dialog);
            liveView.setContentView(R.layout.liveview_dialogue);
            TextView title = (TextView)liveView.findViewById(R.id.liveViewTitle);           
            Button button = (Button) liveView.findViewById(R.id.liveViewButton);
            ImageView trackImage = (ImageView)liveView.findViewById(R.id.liveViewImage);

            //I want to loop through the ten images here? 

            button.setOnClickListener(new OnClickListener() {

                public void onClick(View v) {

                }
            });
            liveView.show();



        }

    }

Answer 1

创建处理程序，并通过postDelayed向其发送延迟2秒的消息。每当收到消息时，通过调用trackImage.setImage显示下一个图像。当他们最终关闭对话框时，从处理程序中删除所有待处理的消息。

Answer 2

要使用一些代码完成答案，以下是我使用处理程序的方法。我不需要传递任何变量，因为我为AsyncTask创建了全局位图的ListArray。如果对话框已关闭，我还使用布尔值来结束处理程序。

        liveView = new Dialog(myView.this, R.style.Dialog);
        liveView.setContentView(R.layout.liveview_dialogue);
        TextView title = (TextView)liveView.findViewById(R.id.liveViewTitle);           
        Button button = (Button) liveView.findViewById(R.id.liveViewButton);
        trackImage = (ImageView)liveView.findViewById(R.id.liveViewImage);





        button.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                run = false;
                liveView.dismiss();
            }
        });
        liveView.show();

        final Handler handler = new Handler(); 
        final Runnable r = new Runnable()
        {
            Iterator<Bitmap> it = images.iterator();
            public void run() 
            {   
                if(run){
                trackImage.setImageBitmap(it.next());
                if(it.hasNext())
                handler.postDelayed(this, 5000);
                }
            }
        };
        handler.postDelayed(r, 5000);

在对话框中显示更改的图片循环？

2 个答案: