在单击按钮时延迟加载

Question

在我的应用程序中，当我单击按钮时，进度条将在最近启动。我想快点开始。谁能帮帮我吗。在onCreate()中展示礼物侦听器。

bShowGifts.setOnClickListener(new OnClickListener()  
{                          

@Override        
        public void onClick(View v) 
        {               
            //vsChange
            progressDlg = ProgressDialog.show(Ehome.this, "", "", true);                            
            progressDlg.setContentView(R.layout.custom_dialog);                
            //Gender and age must be selected
            if(ElGiftoAppData.getAppData().arSelectedGender.size() == 0)  
            {
                progressDlg.dismiss();  
                String strMsg = "Please select a gender";
                DisplaySelectionMessage(strMsg);             
                return;
            }

            if(ElGiftoAppData.getAppData().arSelectedAge.size() == 0)
            {
                progressDlg.dismiss();
                String strMsg = "Please select an age";  
                DisplaySelectionMessage(strMsg);               
                return;
            }

            if(nMatchingGifts == 0)
            {
                progressDlg.dismiss(); 
                tvCount = (TextView) findViewById(R.id.textMatchinGifts);
                String strContent = "# of Matching Gifts: 0";
                tvCount.setText(strContent);                                                        
                String strMsg = "No gifts found! Please change the search criteria.";
                DisplaySelectionMessage(strMsg);               
                return; 
            }               

            try
            {                   
                //Thread for getting the negative attributes values
                Thread tDisplayCategories = new Thread() 
                {
                    public void run()
                    {  


                        System.out.println("Showgifts : Thread:run");
                        handlerDisplayGifts.post(call_ShowGiftsCategoryPage);
                    }                                                                                          
                };
                tDisplayCategories.start();
            }
            catch(Exception exp)
            {
                progressDlg.dismiss();
            }
            return;
            }         
    });

    public void DisplaySelectionMessage(String strMsg)
{

            //display alert dialog            
    AlertDialog alertDialog = new AlertDialog.Builder(Ehome.this).create();
    alertDialog.setTitle("Elgifto Alert");
    alertDialog.setMessage(strMsg);
    alertDialog.setButton("OK", new DialogInterface.OnClickListener() 
    {           
        public void onClick(DialogInterface dialog, int id) 
        {                
            dialog.cancel();
        }
    });

    alertDialog.show();
    return;
}

更新代码

bShowGifts.setOnClickListener(new OnClickListener()  

{                          
        @Override        
            public void onClick(View v) 
        {               
          new showgiftsbtn().execute();
            }         
});

public class showgiftsbtn extends AsyncTask<Void, Void, Void>

{

private final ProgressDialog dialog = new ProgressDialog(Ehome.this);

        protected void onPreExecute()
        {
            this.dialog.setMessage("Please Wait...");
            this.dialog.show();



        // put your code which preload with processDialog  
        if(ElGiftoAppData.getAppData().arSelectedGender.size() == 0)  
        {
            dialog.dismiss();  
            String strMsg = "Please select a gender";
            DisplaySelectionMessage(strMsg);             
            return;
        }

        if(ElGiftoAppData.getAppData().arSelectedAge.size() == 0)
        {
            dialog.dismiss();
            String strMsg = "Please select an age";  
            DisplaySelectionMessage(strMsg);               
            return;
        }

        if(nMatchingGifts == 0)
        {
            dialog.dismiss(); 
            tvCount = (TextView) findViewById(R.id.textMatchinGifts);
            String strContent = "# of Matching Gifts: 0";
            tvCount.setText(strContent);                                                        
            String strMsg = "No gifts found! Please change the search criteria.";
            DisplaySelectionMessage(strMsg);               
            return; 
        }               

        try
        {                   
            //Thread for getting the negative attributes values
            Thread tDisplayCategories = new Thread() 
            {
                public void run()
                {  
                    System.out.println("Showgifts : Thread:run");
                    handlerDisplayGifts.post(call_ShowGiftsCategoryPage);
                    dialog.dismiss();
                }                                                                                          
            };
            tDisplayCategories.start();
        }
        catch(Exception exp)
        {
            dialog.dismiss();
        }
    }

    @Override
    protected Void doInBackground(Void... arg0)
    {           
        // put you code here
        return null;
    }
    protected void onPostExecute(final Void unused)
    {           

    }
}

Answer 1

尝试如下：： AsyncTask支持正确和容易地使用UI线程。这个类允许在UI线程上执行后台操作和发布结果，而不必操作线程和/或处理程序。

异步任务由运行在后台线程上并在UI线程上发布其结果的计算定义。异步任务由3种泛型类型定义，称为Params、进度和结果，以及4个步骤，称为onPreExecute、doInBackground、onProgressUpdate和onPostExecute。

    private class xyz extends AsyncTask<Void, Void, Void> {
                private final ProgressDialog dialog = new ProgressDialog(tranning.this);

                protected void onPreExecute() {
                    this.dialog.setMessage("Please Wait...");
                    this.dialog.show();

                    // put your code which preload with processDialog  


            @Override
            protected Void doInBackground(Void... arg0) {

                // put you code here
if(ElGiftoAppData.getAppData().arSelectedGender.size() == 0)  
            {

                String strMsg = "Please select a gender";
                DisplaySelectionMessage(strMsg);             
                return;
            }

            if(ElGiftoAppData.getAppData().arSelectedAge.size() == 0)
            {
                progressDlg.dismiss();
                String strMsg = "Please select an age";  
                DisplaySelectionMessage(strMsg);               
                return;
            }

        if(nMatchingGifts == 0)
        {

            tvCount = (TextView) findViewById(R.id.textMatchinGifts);
            String strContent = "# of Matching Gifts: 0";
            tvCount.setText(strContent);                                                        
            String strMsg = "No gifts found! Please change the search criteria.";
            DisplaySelectionMessage(strMsg);               
            return; 
        }               

        try
        {                   
            //Thread for getting the negative attributes values
            Thread tDisplayCategories = new Thread() 
            {
                public void run()
                {  


                    System.out.println("Showgifts : Thread:run");
                    handlerDisplayGifts.post(call_ShowGiftsCategoryPage);
                }                                                                                          
            };
            tDisplayCategories.start();
        }
        catch(Exception exp)
        {

        }
            }

                return null;
            }
protected void onPostExecute(final Void unused) {
                if (this.dialog.isShowing()) {
                  this.dialog.dismiss();

                }

            }
        }

并在单击event ::按钮中使用此方法

 new xyz().execute();

Answer 2

用Handler显示ProgressBar() ..。

private Handler mHandler = new Handler();

final Runnable mUpdateResults = new Runnable() {
       public void run() {
      progressDlg = ProgressDialog.show(Ehome.this, "", "", true);                            
            progressDlg.setContentView(R.layout.custom_dialog);
       }
};

将上面的代码放在类代码之上，并在显示progressBar()的地方调用它；如下所示：

mHandler.post(mUpdateResults );