如何留住进度条状态，而切换片段？ [英] How to retain progress bar state while switching the fragments?
本文介绍了如何留住进度条状态，而切换片段？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有一个导航抽屉里这么多的选项是present
I have a navigation drawer where these many options are present
- 图像材料
- 视频材料
- 音频材料
我们正在维护独立的片段每种材料和每一个片段，在我们所填充的材料的缩略图网格视图。一旦用户点击缩略图完整的材料将被下载（使用AsyncTask的）。我在显示缩略图的进度栏下载完整的材料。
We are maintaining separate fragment for each material and every fragment have grid view in which we are populating thumbnail of that material. Once user click on the thumbnail a full material will be downloaded(Using AsyncTask). I am displaying the progress bar over the thumbnail while downloading the full material.
现在在这里，我坚持到设进度条显示20％的问题，我换了片段到另一个，并再次回到相同，下载进度条会丢失。
Now here i stuck to a problem that suppose progress bar is showing 20% and i switched the fragment to another and again came back to the same and the downloading progress bar is lost.
我去了一个解决方案中使用意向的服务和广播接收器来填充进度条，但每增加这种情况下，字节的广播会做它是一个好的做法呢？
I went to a solution to use intent service and broadcast receiver to populate the progress bar but in that case on every added bytes a broadcasting will be done is it a good practice ?
推荐答案
在previous答案是不够好，我做了一个新的，一看，它工作得很好。
The previous answer wasn't good enough, I made up a new one, have a look, it works very well.
在code由基类片段，两个片段，型号的用于保存数据网格元素和主UI线程。
The code consists of the Base Class for fragments, Two fragments, Model for holding data for grid elements and Main UI thread.
的基类：
import android.app.Activity;
import android.app.Fragment;
import android.content.Context;
import android.graphics.Color;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ProgressBar;
import android.widget.RelativeLayout;
import android.widget.TextView;
import java.util.ArrayList;
/**
* Created by Movsar Bekaev on 20/09/2015.
*/
public class GridFragment extends Fragment {
static ArrayList<xThumbnail> myInformation;
static Activity mActivity;
GAdapter adapter;
GridView grid;
enum fragment_names {FR1, FR2}
static fragment_names this_fragment_name;
public GridFragment() {
refresh();
}
protected void refresh() {
if (grid == null) {
grid = new GridView(mActivity);
grid.setLayoutParams(new GridView.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT));
grid.setBackgroundColor(Color.WHITE);
grid.setNumColumns(2);
grid.setColumnWidth(GridView.AUTO_FIT);
grid.setVerticalSpacing(5);
grid.setHorizontalSpacing(5);
grid.setStretchMode(GridView.STRETCH_COLUMN_WIDTH);
}
adapter = new GAdapter(mActivity, myInformation);
grid.setAdapter(adapter);
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
refresh();
return grid;
}
public class GAdapter extends BaseAdapter {
private Context mContext;
private ArrayList<xThumbnail> mInfo;
// Gets the context so it can be used later
public GAdapter(Context c, ArrayList<xThumbnail> info) {
mInfo = info;
mContext = c;
}
// Total number of things contained within the adapter
public int getCount() {
return mInfo.size();
}
public xThumbnail getItem(int position) {
return mInfo.get(position);
}
// Require for structure, not really used in my code. Can
// be used to get the id of an item in the adapter for
// manual control.
public long getItemId(int position) {
return position;
}
public View getView(final int position,
View convertView, ViewGroup parent) {
View v;
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = inflater.inflate(R.layout.thumbnail, null);
final TextView tv = (TextView) v.findViewById(R.id.tvClickMe);
final ProgressBar pb = (ProgressBar) v.findViewById(R.id.prgb_progress);
pb.setProgress(mInfo.get(position).getProgress());
tv.setText(mInfo.get(position).getProgress() + "");
mInfo.get(position).setProgressBar(pb);
mInfo.get(position).setTextView(tv);
tv.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
runOp(mInfo.get(position), position, this_fragment_name);
}
});
} else {
v = convertView;
}
return v;
}
}
private void runOp(final xThumbnail x, final int position, final fragment_names f_name) {
if (x.xt == null) {
x.xt = new Thread(new Runnable() {
@Override
public void run() {
for (int i = x.getProgress(); i <= 100; i++) {
// UNCOMMENT IF YOU WANT TO STOP THE PROCESS AFTER SWITCHING
// if ((f_name == this_fragment_name) && !mThread.isInterrupted()) {
final int progress = i;
mActivity.runOnUiThread(new Runnable() {
@Override
public void run() {
x.setProgressBar(adapter.getItem(position).getProgressBar());
x.setTextView(adapter.getItem(position).getTextView());
x.setProgress(progress);
x.getProgressBar().setProgress(progress);
x.getTextView().setText(progress + "");
// ARBITRARY CHANGE OF MYINFORMATION
// JUST TO SHOW THAT IT WORKS
if (progress == 20) {
myInformation.get(3).setProgress(12);
refresh();
}
// **********************************
}
});
try {
Thread.sleep(150);
} catch (InterruptedException e) {
e.printStackTrace();
}
// } else {
// return;
// }
}
}
});
}
if (!x.xt.isAlive())
x.xt.start();
}
}
的fr1.java：
public class fr1 extends GridFragment {
static ArrayList<xThumbnail> fr1Info;
public static fr1 newInstance(Activity act) {
mActivity = act;
return new fr1();
}
@Override
protected void refresh() {
if (fr1Info == null || fr1Info.size() == 0) {
fr1Info = new ArrayList<>();
for (int i = 0; i < 10; i++) {
xThumbnail x;
x = new xThumbnail();
fr1Info.add(x);
}
}
myInformation = fr1Info;
super.refresh();
}
}
的fr2.java：
public class fr2 extends GridFragment {
static ArrayList<xThumbnail> fr2Info;
public static fr2 newInstance(Activity act) {
mActivity = act;
return new fr2();
}
@Override
protected void refresh() {
if (fr2Info == null || fr2Info.size() == 0) {
fr2Info = new ArrayList<>();
for (int i = 0; i < 10; i++) {
xThumbnail x;
x = new xThumbnail();
fr2Info.add(x);
}
}
myInformation = fr2Info;
super.refresh();
}
}
的xThumbnail.java（模型）：
public class xThumbnail {
private int prgb_value = 0;
private ProgressBar pb;
private TextView tv;
public Thread xt;
public void setProgress(Integer i) {
prgb_value = i;
}
public Integer getProgress() {
return prgb_value;
}
public void setProgressBar(ProgressBar prb) {
pb = prb;
}
public ProgressBar getProgressBar() {
return pb;
}
public void setTextView(TextView tv) {
this.tv = tv;
}
public TextView getTextView() {
return tv;
}
}
的MainActivity.java：
public class MainActivity extends AppCompatActivity {
Button btn_one, btn_two;
fr1 mFr1;
fr2 mFr2;
FragmentManager fm = getFragmentManager();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn_one = (Button) findViewById(R.id.btn_one);
btn_two = (Button) findViewById(R.id.btn_two);
mFr1 = (fr1) fm.findFragmentByTag("fr1");
mFr2 = (fr2) fm.findFragmentByTag("fr2");
final FrameLayout frameLayout = (FrameLayout)findViewById(R.id.frLayout);
btn_one.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
GridFragment.this_fragment_name= GridFragment.fragment_names.FR1;
if (mFr1 == null) {
mFr1 = fr1.newInstance(MainActivity.this);
fm.beginTransaction().add(R.id.frLayout, mFr1, "fr1").commit();
} else {
fm.beginTransaction().detach(mFr1).commit();
fm.beginTransaction().attach(mFr1).commit();
}
}
});
btn_two.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
GridFragment.this_fragment_name= GridFragment.fragment_names.FR2;
if (mFr2 == null) {
mFr2 = fr2.newInstance(MainActivity.this);
fm.beginTransaction().add(R.id.frLayout, mFr2, "fr2").commit();
} else{
fm.beginTransaction().detach(mFr2).commit();
fm.beginTransaction().attach(mFr2).commit();
}
}
});
}
}
activity_main.xml中：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="1"
android:id="@+id/btn_one"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="2"
android:id="@+id/btn_two"
android:layout_alignParentBottom="true"
android:layout_alignRight="@+id/prgb_uni"
android:layout_alignEnd="@+id/prgb_uni" />
<ProgressBar
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/prgb_uni"
android:layout_alignParentBottom="true"
android:layout_marginBottom="40dp"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true" />
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:id="@+id/frLayout"></FrameLayout>
</RelativeLayout>
thumbnail.xml：
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<ProgressBar
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/prgb_progress" />
<TextView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="ClickMe!"
android:id="@+id/tvClickMe"
android:layout_gravity="center_horizontal"
android:textIsSelectable="false" />
</FrameLayout>
它的作用：
我们这里有一个基类，它的意见再presentation和填充进度条进行操作。
它有场电流项工作（保存进度栏的值），每当我们这个字段片段之间的切换时间被更新为片段1或Fragment2的各自的值，这些片段具有静态字段来保存它们自己的数据，以便它可以被改变和使用。
What it does: We have here one base class, it operates with representation of views and populating progress bars. It has field to work with current items (that holds progress bar values), every time when we switching between fragments this field is updated to respective values of Fragment1 or Fragment2, those fragments have static fields to hold their own data so it can be changed and used.
用螺纹和其他一些code事情只是为了表明它的作品，并更好地理解。
The thing with Thread and some other code is just to show that it's works and for better understanding.
我希望这会有所帮助。
的PoC - https://youtu.be/uKGeX40z_mA ：）
PoC - https://youtu.be/uKGeX40z_mA :)
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