如何设置进度条？

Question

public class AndroidXMLParsingActivity extends Activity {

    public int currentPage = 1;
    public ListView lisView1;
    static final String KEY_ITEM = "docdetails";
    static final String KEY_NAME = "heading";
    public Button btnNext;
    public Button btnPre;
    public static String url = "http://dev.taxmann.com/TaxmannService/TaxmannService.asmx/GetNotificationList";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        // listView1
        lisView1 = (ListView) findViewById(R.id.listView1);

        // Next
        btnNext = (Button) findViewById(R.id.btnNext);
        // Perform action on click
        btnNext.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                currentPage = currentPage + 1;
                ShowData();
            }
        });

        // Previous
        btnPre = (Button) findViewById(R.id.btnPre);
        // Perform action on click
        btnPre.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                currentPage = currentPage - 1;
                ShowData();
            }
        });

        ShowData();
    }

    public void ShowData() {
        XMLParser parser = new XMLParser();
        String xml = parser.getXmlFromUrl(url); // getting XML



          Document  doc = parser.getDomElement(xml);

        NodeList nl = doc.getElementsByTagName(KEY_ITEM);

        int displayPerPage = 5; // Per Page
        int TotalRows = nl.getLength();
        int indexRowStart = ((displayPerPage * currentPage) - displayPerPage);
        int TotalPage = 0;
        if (TotalRows <= displayPerPage) {
            TotalPage = 1;
        } else if ((TotalRows % displayPerPage) == 0) {
            TotalPage = (TotalRows / displayPerPage);
        } else {
            TotalPage = (TotalRows / displayPerPage) + 1; // 7
            TotalPage = (int) TotalPage; // 7
        }
        int indexRowEnd = displayPerPage * currentPage; // 5
        if (indexRowEnd > TotalRows) {
            indexRowEnd = TotalRows;
        }

        // Disabled Button Next
        if (currentPage >= TotalPage) {
            btnNext.setEnabled(false);
        } else {
            btnNext.setEnabled(true);
        }

        // Disabled Button Previos
        if (currentPage <= 1) {
            btnPre.setEnabled(false);
        } else {
            btnPre.setEnabled(true);
        }

        // Load Data from Index
        int RowID = 1;
        ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>();
        HashMap<String, String> map;

        // RowID
        if (currentPage > 1) {
            RowID = (displayPerPage * (currentPage - 1)) + 1;
        }

        for (int i = indexRowStart; i < indexRowEnd; i++) {
            Element e = (Element) nl.item(i);
            // adding each child node to HashMap key => value
            map = new HashMap<String, String>();
            map.put("RowID", String.valueOf(RowID));
            map.put(KEY_NAME, parser.getValue(e, KEY_NAME));

            // adding HashList to ArrayList
            menuItems.add(map);

            RowID = RowID + 1;

        }

        SimpleAdapter sAdap;
        sAdap = new SimpleAdapter(AndroidXMLParsingActivity.this, menuItems,
                R.layout.list_item, new String[] { "RowID", KEY_NAME },
                new int[] { R.id.ColRowID, R.id.ColName });
        lisView1.setAdapter(sAdap);
    }

}

这是我的源代码，我想设置ProgressBar这个活动是从另一个活动调用按钮点击我想要设置ProgressBar当数据加载ShowData（）函数时我们用于解析打印，并且分页我试过很多但是我我无法使用ProgressBar加载数据请告诉我如何实现它。

Answer 1

有一些很好的教程（ex http://eagle.phys.utk.edu/guidry/android/progressBarExample.html）

Answer 2

试试这段代码，它会起作用..

public class AndroidXMLParsingActivity extends Activity {

    public int currentPage = 1;
    public ListView lisView1;
    static final String KEY_ITEM = "docdetails";
    static final String KEY_NAME = "heading";
    public Button btnNext;
    public Button btnPre;
    public static String url = "http://dev.taxmann.com/TaxmannService/TaxmannService.asmx/GetNotificationList";
    SimpleAdapter sAdap;
    ProgressDialog progressDialog;
    Activity mActivity;
    ArrayList<HashMap<String, String>> menuItems;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mActivity = this;
        // listView1
        lisView1 = (ListView) findViewById(R.id.listView1);

        // Next
        btnNext = (Button) findViewById(R.id.btnNext);
        // Perform action on click
        btnNext.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                currentPage = currentPage + 1;
                new backProcess().execute();
            }
        });

        // Previous
        btnPre = (Button) findViewById(R.id.btnPre);
        // Perform action on click
        btnPre.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                currentPage = currentPage - 1;
                new backProcess().execute();
            }
        });

        new backProcess().execute();
    }

    public void ShowData() {
        XMLParser parser = new XMLParser();
        String xml = parser.getXmlFromUrl(url); // getting XML

        Document doc = parser.getDomElement(xml);

        NodeList nl = doc.getElementsByTagName(KEY_ITEM);

        int displayPerPage = 5; // Per Page
        int TotalRows = nl.getLength();
        int indexRowStart = ((displayPerPage * currentPage) - displayPerPage);
        int TotalPage = 0;
        if (TotalRows <= displayPerPage) {
            TotalPage = 1;
        } else if ((TotalRows % displayPerPage) == 0) {
            TotalPage = (TotalRows / displayPerPage);
        } else {
            TotalPage = (TotalRows / displayPerPage) + 1; // 7
            TotalPage = (int) TotalPage; // 7
        }
        int indexRowEnd = displayPerPage * currentPage; // 5
        if (indexRowEnd > TotalRows) {
            indexRowEnd = TotalRows;
        }

        // Disabled Button Next
        if (currentPage >= TotalPage) {
            btnNext.setEnabled(false);
        } else {
            btnNext.setEnabled(true);
        }

        // Disabled Button Previos
        if (currentPage <= 1) {
            btnPre.setEnabled(false);
        } else {
            btnPre.setEnabled(true);
        }

        // Load Data from Index
        int RowID = 1;
        menuItems = new ArrayList<HashMap<String, String>>();
        HashMap<String, String> map;

        // RowID
        if (currentPage > 1) {
            RowID = (displayPerPage * (currentPage - 1)) + 1;
        }

        for (int i = indexRowStart; i < indexRowEnd; i++) {
            Element e = (Element) nl.item(i);
            // adding each child node to HashMap key => value
            map = new HashMap<String, String>();
            map.put("RowID", String.valueOf(RowID));
            map.put(KEY_NAME, parser.getValue(e, KEY_NAME));

            // adding HashList to ArrayList
            menuItems.add(map);

            RowID = RowID + 1;

        }

    }

    public class backProcess extends AsyncTask<Void, Void, Void> {

        @Override
        protected void onPostExecute(Void result) {
            if (progressDialog != null)
                progressDialog.dismiss();
            sAdap = new SimpleAdapter(AndroidXMLParsingActivity.this,
                    menuItems, R.layout.list_item, new String[] { "RowID",
                            KEY_NAME },
                    new int[] { R.id.ColRowID, R.id.ColName });
            lisView1.setAdapter(sAdap);
            super.onPostExecute(result);
        }

        @Override
        protected void onPreExecute() {
            progressDialog = ProgressDialog.show(mActivity, "Wait",
                    "Loading...");
            super.onPreExecute();
        }

        @Override
        protected Void doInBackground(Void... params) {
            ShowData();
            return null;
        }

    }

}

Answer 3

使用异步任务加载数据

private class Data extends AsyncTask<Object, Integer, Object> {

        @Override
        protected void onPreExecute() {

             ProgressDialog progress = ProgressDialog.show(Activity.this, "",
                    "Loading...");

            super.onPreExecute();
        }

        @Override
        protected Object doInBackground(Object... params) {
            //do hard work here
                            ShowData();
                                return null;
        }

        @Override
        protected void onProgressUpdate(Integer... values) {
            progress.getProgress();

        }

        @Override
        protected void onPostExecute(Object result) {

            progressBar.dismiss();


            super.onPostExecute(result);
        }
    } 

和onclick方法

new Data().execute().

Answer 4

将异步类设为public static，然后您可以从任何地方访问它。

private class Data extends AsyncTask<Object, Integer, Object> {

    @Override
    protected void onPreExecute() {

         ProgressDialog progress = ProgressDialog.show(Activity.this, "",
                "Loading...");

        super.onPreExecute();
    }

    @Override
    protected Object doInBackground(Object... params) {
        //do hard work here
                        ShowData();
                            return null;
    }

    @Override
    protected void onProgressUpdate(Integer... values) {
        progress.getProgress();

    }

    @Override
    protected void onPostExecute(Object result) {

        progressBar.dismiss();


        super.onPostExecute(result);
    }
}