Question

我正在研究Android。我希望在与www.google.com的连接成功后仅显示进度条10秒。这是我的代码。任何帮助表示赞赏。

MainActivity.java

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.ProgressBar;

public class MainActivity extends AppCompatActivity {
    Button button1;
    Public ProgressBar mProgress;
    progressCheck obj = new progressCheck(mProgress);
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        Button fab = (Button) findViewById(R.id.button1);
        mProgress =(ProgressBar) findViewById(R.id.progressBar);
        mProgress.setVisibility(View.GONE);

        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                    obj.execute();
            }
        });


    }

ProgressCheck.java扩展了AsyncTask

   import android.os.AsyncTask;
import android.view.View;
import android.widget.ProgressBar;

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;

import java.io.IOException;

public class progressCheck  extends AsyncTask<String, String, String> {
    ProgressBar mProgressBar;

    public progressCheck(ProgressBar p){
        this.mProgressBar = p;
    }


    @Override
    protected String doInBackground(String... params) {

        Document doc = null;
        String url = "https://www.google.com.pk/";
        try {
            doc = Jsoup.connect(url).timeout(20 * 1000).get();
            Thread.sleep(10000);
        } catch (IOException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        return null;
    }

    @Override
    protected void onPostExecute(String result) {
        mProgressBar.setVisibility(View.GONE);

    }


    @Override
    protected void onPreExecute() {
        mProgressBar.setVisibility(View.VISIBLE);
    }

    @Override
    protected void onProgressUpdate(String... text) {


    }

}

Content_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.example.namal.circularprogressbar2.MainActivity"
    tools:showIn="@layout/activity_main">

    <ProgressBar
        style="?android:attr/progressBarStyleLarge"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/progressBar"
        android:layout_marginTop="36dp"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:indeterminate="false" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Start"
        android:id="@+id/button1"
        android:layout_below="@+id/progressBar"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="72dp" />


</RelativeLayout>

Answer 1

在onPreExecute（）中将Visibility设置为Visible，在onPostExecute（）中设置为Gone

@Override
protected void onPostExecute(String result) {
     mProgress.setVisibility(View.GONE);
}

@Override
protected void onPreExecute() {
    mProgress.setVisibility(View.VISIBLE);
}

编辑：在AsyncTask中定义进度条。

ProgressBar mProgress;

为Asynctask创建构造函数并将progressbar引用传递给它。

public progressCheck(ProgressBar progressbar){
   this.mProgress = progressbar;

}

在您的活动中称之为progressCheck obj = new progressCheck(mProgress);

EDIT2：MainActivity

public class MainActivity extends AppCompatActivity {
Button button1;
Public ProgressBar mProgress;
progressCheck obj;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    Button fab = (Button) findViewById(R.id.button1);
    mProgress =(ProgressBar) findViewById(R.id.progressBar);
    obj = new progressCheck(mProgress);
    mProgress.setVisibility(View.GONE);

    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
                obj.execute();
        }
    });


}

Answer 2

new AsyncTask<Void, Void, Void>
{
    ProgressDialog pd = new ProgressDialog(MainActivity.this);
    @Override
    protected void onPreExecute() {
        super.onPreExecute();

        pd.setTitle("Please wait");
        pd.setMessage("Connecting to Google...");
        pd.setCancelable(false);
        pd.show();
    }


    @Override
    protected Void doInBackground(Void... params) {
        try{
           Thread.sleep(YOUR_TIME);
        } 
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }

    @Override
    protected void onPostExecute(Void aVoid) 
    {
        super.onPostExecute(aVoid);
        if (pd!=null && pd.isShowing())
        {
            pd.dismiss();
        }
    }
}.execute();

现在管理您的要求.. 希望这会有所帮助..

Answer 3

从onClick（）方法中删除mProgress行。

fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                    obj.execute(); 
            }
        });

在onPreExecute（）方法中添加这些mProgress可见性行，在onPostExecute（）方法中添加mProgress Gone。

@Override
protected void onPostExecute(String result) {
   mProgress.setVisibility(View.GONE);
}


@Override
protected void onPreExecute() {
   mProgress.setVisibility(View.VISIBLE);
}

修改

将mProgress传递给progressCheck类。

progressCheck obj = new progressCheck(mProgress);

并在progressCheck构造函数中获取它。

ProgressBar progress; public progressCheck(ProgressBar mProgress){ progress = mProgress; }

Async ovrridden方法就像......

@Override protected void onPostExecute(String result) { progress.setVisibility(View.GONE); } @Override protected void onPreExecute() { progress.setVisibility(View.VISIBLE); }

Answer 4

你要做的就是在你的AsyncTask onPostExecute中编写这段代码。

ChatCell

完整代码

public class ChatCell extends ListCell<ChatItem> {

    private ChatItemView view;
    private InvalidationListener listViewListener;
    private InvalidationListener listViewWidthListener;

    public ChatCell() {
        setContentDisplay(ContentDisplay.GRAPHIC_ONLY);

        listViewWidthListener = e -> {
            updateItem(getItem(), isEmpty());
        };

        listViewListener = e -> {
            if(getView() == null) return;
            getView().unbindWidth();
            if(listViewProperty().get() != null) {
                getView().bindWidth(listViewProperty().get().widthProperty());
                listViewProperty().get().widthProperty().addListener(listViewWidthListener);
                listViewWidthListener.invalidated(listViewProperty().get().widthProperty());
            }
        };

    }

    public ChatItemView getView() {
        return view;
    }

    private void initChatLabelView() {
        view = new ChatLabelView();
    }

    private void initChatMessageView(ChatMessage message) {
        view = new ChatMessageViewWrapper(message);
    }


    private void resetView() {
        if(view == null) return;
        view.unbindWidth();
        listViewProperty().removeListener(listViewListener);
        if(getListView() != null)
            getListView().widthProperty().removeListener(listViewWidthListener);
        view = null;
    }

    private void newViewCreated() {
        listViewProperty().addListener(listViewListener);
        setGraphic(view);
        listViewListener.invalidated(listViewProperty());
    }

    @Override
    protected void updateItem(ChatItem item, boolean empty) {
        super.updateItem(item, empty);
        if(item == null || empty) {
            setGraphic(null);
            setText(null);
            resetView();
        } else {
            // First-level comparison: Label vs. Message
            if(item.getViewType() == ViewType.LABEL) {
                if(view == null || !(view instanceof ChatLabelView)) {
                    resetView();
                    initChatLabelView();
                    newViewCreated();
                }

            }

            else if(item.getViewType() == ViewType.MESSAGE) {
                ChatMessage message = (ChatMessage) item;
                if(view == null || !(view instanceof ChatMessageViewWrapper)) {
                    resetView();
                    initChatMessageView(message);
                    newViewCreated();
                }
                else {
                    ChatMessageViewWrapper bubble = (ChatMessageViewWrapper) view;
                    // Second-level comparison: Self-message vs. other user message,
                    // Text vs. Image (or file), multiline vs. oneline 
                    if(  (bubble.getContentType() != message.getContentType())
                            || (bubble.isSelf() ^ message.isSelf()) 
                            || (bubble.isMultiline() ^ message.isMultiline())) {
                        resetView();
                        initChatMessageView(message);
                        newViewCreated();
                    }

                }

            }

            else {
                return;
            }

            view.setItem(item);
        }
    }

    @Override
    public Orientation getContentBias() {
        return Orientation.HORIZONTAL;
    }

}

如何在Android中10秒后隐藏进度条？

4 个答案: