Android Development Series (27th): Use ProgressDialog to create a progress dialog box

Android Development Series (27th): Use ProgressDialog to create a progress dialog box

The progress dialog box is common in common applications, such as downloading, opening a page, transferring a file, and so on. It has a circular shape and a long shape. These two types

You can create a progress dialog box in either of the following ways:

1. Create a ProgressDialog instance and call the static show () method provided by ProgressDialog to display the instance.

2. Create a ProgressDialog instance, call the method to set the progress bar, and display it.

 

The progress bar can be divided into two types: the first is the display progress, and the second is the display progress.

In the following example, we will see three types of progress bars: The Ring progress bar, the progress bar, and the progress bar.

 

First, create an Android project and write the main. xml file:

 

Three buttons are defined here. The three buttons correspond to the corresponding onClick attribute.

 

Next, ProgressDialogTest. java:

 

Package org. crazyit. ui; import android. app. activity; import android. app. progressDialog; import android. OS. bundle; import android. OS. handler; import android. OS. message; import android. view. view; public class ProgressDialogTest extends Activity {final static int MAX_PROGRESS = 100; // This program simulates an array with a length of 100 private int [] data = new int [50]; // progress record Dialog Box Completion percentage int progressStatus = 0; int hasData = 0; ProgressDialog pd1, pd2; // Define a HandlerHandler handler that is responsible for updating the progress = new Handler () {@ Overridepublic void handleMessage (Message msg) {// indicates that the Message is sent by the program. If (msg. what = 0x123) {pd2.setProgress (progressStatus) ;}};@ Overridepublic void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. main);} public void showSpinner (View source) {// call the static method to display the circular progress bar ProgressDialog. show (this, "task in progress", "task in progress, please wait", false, true); // ①} public void showIndeterminate (View source) {pd1 = new ProgressDialog (ProgressDialogTest. this); // set the Dialog The title of the box pd1.setTitle ("the task is being executed"); // The content displayed in the Setting Dialog Box pd1.setMessage ("the task is being executed. Please wait... "); // In the Setting dialog box, you can use the" cancel "button to close pd1.setCancelable (true); // you can set the progress bar style pd1.setProgressStyle (ProgressDialog. STYLE_HORIZONTAL); // set whether the progress bar in the dialog box displays pd1.setIndeterminate (true); pd1.show (); // ②} public void showProgress (View source) {// reset the progress bar to 0 progressStatus = 0; // refill the array. HasData = 0; pd2 = new ProgressDialog (ProgressDialogTest. this); pd2.setMax (MAX_PROGRESS); // set the title of the dialog box pd2.setTitle ("task completion percentage "); // set the content displayed in the dialog box pd2.setMessage ("percentage of completed time-consuming tasks"); // The "cancel" button cannot be used to close pd2.setCancelable (false ); // set the progress bar style pd2.setProgressStyle (ProgressDialog. STYLE_HORIZONTAL); // set whether the progress bar in the dialog box shows pd2.setIndeterminate (false); pd2.show (); // ③ new Thread () {public void run () {while (progressStatus <MAX_PROG RESS) {// get the percentage of completed time-consuming operations progressStatus = MAX_PROGRESS * doWork ()/data. length; // send an empty message to Handlerhandler. sendEmptyMessage (0x123);} // if the task has been completed if (progressStatus >=max_progress) {// close the dialog box pd2.dismiss ();}}}. start () ;}// simulate a time-consuming operation. Public int doWork () {// assign data [hasData ++] = (int) (Math. random () * 100); try {Thread. sleep (100);} catch (InterruptedException e) {e. printStackTrace () ;}return hasData ;}}

In the third step: display the progress bar, we use the Thread to simulate a time-consuming operation.

 

 

This is: