android – 包含TableLayouts的片段的ViewPager加载缓慢：

我正在使用ViewPager开发一个Activity,其中包含Fragments(每次最多4个片段),每个包含TableLayout.所以基本上加载了4个表.这是用于将数据加载到Fragment中的代码,该片段稍后附加到ViewPager：

public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) 
{
    if (container == null) {
        return null;
    }

    LinearLayout.LayoutParams layoutParams=new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
    layoutParams.gravity=Gravity.CENTER_VERTICAL;
    layoutParams.setMargins(10,0);

    fragmetLayout = (LinearLayout)inflater.inflate(R.layout.grid_fragment_layout,container,false);
    table = (TableLayout) fragmetLayout.findViewById(R.id.tlGridTable);
    llParameterContainer =  (LinearLayout) fragmetLayout.findViewById(R.id.llParametersContainer);
    tabName = (TextView) fragmetLayout.findViewById(R.id.tvTabName);
    tabName.setText(tab.getTabName());
    //tabName.setLayoutParams(layoutParams);

    for (Parameter parameter : SGRaportManagerAppObj.getInstance().parametersRepository.getParametersRepository())
    {
        ImageView parameterPoint = new ImageView(getActivity());
        parameterPoint.setImageResource(R.drawable.parameter_chosen_point);
        parameterPoint.setPadding(10,10,0);
        parameterPoint.setLayoutParams(layoutParams);
        llParameterContainer.addView(parameterPoint);

        TextView parameterTextView = new TextView(getActivity());
        parameterTextView.setText(parameter.getName()+":");
        parameterTextView.setGravity(Gravity.CENTER);
        parameterTextView.setTextColor(getResources().getColor(R.color.my_black));  
        parameterTextView.setPadding(5,3,10);
        parameterTextView.setLayoutParams(layoutParams);
        llParameterContainer.addView(parameterTextView);
        TextView parameterChosenValueTextView = new TextView(getActivity());
        parameterChosenValueTextView.setText(parameter.getChosenValue());
        parameterChosenValueTextView.setGravity(Gravity.CENTER); 
        parameterChosenValueTextView.setPadding(0,10);
        parameterChosenValueTextView.setLayoutParams(layoutParams);
        parameterChosenValueTextView.setTextColor(getResources().getColor(R.color.my_black));   
        llParameterContainer.addView(parameterChosenValueTextView);

    }
    //table.setStretchAllColumns(true);  
    //table.setShrinkAllColumns(true); 
    TableRow tableRow = new TableRow(getActivity());
    TableLayout.LayoutParams tableRowParams=new TableLayout.LayoutParams(TableLayout.LayoutParams.WRAP_CONTENT,TableLayout.LayoutParams.WRAP_CONTENT);
    tableRowParams.setMargins(2,0);
    tableRow.setLayoutParams(tableRowParams);
    Log.d(TAG,"TAB FROM FRAGMENT:"+tab.toString());


    TableRow.LayoutParams tlparamsFirstColumn = new TableRow.LayoutParams(TableRow.LayoutParams.WRAP_CONTENT,TableRow.LayoutParams.WRAP_CONTENT); 
    tlparamsFirstColumn.setMargins(4,2,0);
    TableRow.LayoutParams tlparams = new TableRow.LayoutParams(TableRow.LayoutParams.WRAP_CONTENT,TableRow.LayoutParams.WRAP_CONTENT); 
    tlparams.setMargins(0,0);

    //The First row for the column names.
    for (int i= 0; i < tab.getGrid().getGridColumnsList().size(); i++)
    {
        TextView tvName = new TextView(getActivity());
        String columnName = tab.getGrid().getGridColumnsList().get(i).getGridColumnAlias();
        tvName.setText(columnName);
        Log.d(TAG,"COLUMN ALIAS FROM FRAGMENT: "+columnName);
        if (i == 0)
        {
            tvName.setLayoutParams(tlparamsFirstColumn);
        }
        else
        {
            tvName.setLayoutParams(tlparams);
        }
        tvName.setGravity(Gravity.CENTER);
        tvName.setTextColor(getResources().getColor(R.color.my_white));  
        tvName.setPadding(10,10);
        tvName.setBackgroundDrawable(getResources().getDrawable(R.drawable.grid_column_name_background));   
        tableRow.addView(tvName);
    }
    table.addView(tableRow);

    for (int j = 0; j < tab.getGrid().getGridData().getNumRows(); j++)
    {
        TableRow newRow = new TableRow(getActivity());
        TableLayout.LayoutParams insideRowParams=new TableLayout.LayoutParams(TableLayout.LayoutParams.WRAP_CONTENT,TableLayout.LayoutParams.WRAP_CONTENT);
        tableRowParams.setMargins(0,0);
        for (int k = 0; k < tab.getGrid().getGridData().getNumCols(j); k++)
        {
            TextView tvName = new TextView(getActivity());
            String columnName = tab.getGrid().getGridData().get(j,k);
            tvName.setText(columnName);

            if ( (j % 2) == 0)
            {
                tvName.setBackgroundDrawable(getResources().getDrawable(R.drawable.grid_first_row_background)); 
            }
            else
            {
                tvName.setBackgroundDrawable(getResources().getDrawable(R.drawable.grid_second_row_background));    
            }
            if (k == 0)
            {
                tvName.setLayoutParams(tlparamsFirstColumn);
            }
            else
            {
                tvName.setLayoutParams(tlparams);
            }
            tvName.setGravity(Gravity.CENTER);
            tvName.setTextColor(getResources().getColor(R.color.my_black));  
            tvName.setPadding(10,10);
            newRow.addView(tvName);  
        }
        table.addView(newRow);          
    }
    return fragmetLayout;
}

更新：

我的ViewPagerActivity布局：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<TabHost
    android:id="@android:id/tabhost"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_below="@+id/imageView3" >

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" >
        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:layout_weight="0"/>

        <android.support.v4.view.ViewPager
            android:id="@+id/pager"
            android:layout_width="fill_parent"
            android:layout_height="0dp"
            android:layout_weight="1" >
        </android.support.v4.view.ViewPager>

         <TabWidget
            android:id="@android:id/tabs"
            android:orientation="horizontal"
            android:layout_gravity="center_horizontal"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />
    </LinearLayout>
</TabHost>

 <ImageView
    android:id="@+id/imageView3"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="-3dp"
    android:background="@drawable/login_scr_top_bar"
    android:contentDescription="@drawable/login_scr_top_bar" />

<TextView
    android:id="@+id/tvReportName"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="top|left"
    android:paddingLeft="15dp"
    android:paddingTop="13dp"
    android:text="@string/report_tabs"
    android:textColor="@color/my_black"
    android:textSize="18sp"
    android:textStyle="bold" />

<LinearLayout
    android:id="@+id/llTabsButtonsContainer"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentRight="true"
    android:gravity="center_horizontal"
    android:orientation="horizontal"
    android:paddingBottom="5dp"
    android:paddingTop="5dp" > 
</LinearLayout>

<TextView
    android:id="@+id/tvReportTitle"
    android:layout_width="wrap_content"
    android:layout_height="20dp"
    android:layout_alignBaseline="@+id/tvReportName"
    android:layout_alignBottom="@+id/tvReportName"
    android:layout_toLeftOf="@+id/bBackToParameters"
    android:layout_toRightOf="@+id/tvReportName"
    android:text="TextView"
    android:textSize="18sp" />

<Button
    android:id="@+id/bBackToParameters"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@+id/tvReportTitle"
    android:layout_marginRight="10dp"
    android:layout_alignParentRight="true"
    android:background="@drawable/button_back_to_parameters_selector"
    android:clickable="true"
    android:onClick="backToParametersButtonOnClick"
    android:padding="3dp"
    android:text="@string/back_to_parameters"
    android:textColor="@color/my_white"
    android:textStyle="bold" />

</RelativeLayout>

和我的GridFramgnet布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >

<LinearLayout
android:id="@+id/llParametersContainer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
</LinearLayout>

<TextView 
    android:id="@+id/tvTabName"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" 
    android:textColor="@color/my_black"
    android:textStyle="bold"
    android:textSize="18sp"
    android:layout_marginLeft="10dp"
    android:text="It a test string for report Name"/>

    <ScrollView 
    android:id="@+id/layout" 
    android:layout_height="match_parent"         
    android:scrollbars="horizontal|vertical" 
    android:layout_width="match_parent"     
    android:layout_marginTop="5dip"     
    android:scrollbarStyle="outsideInset"
    android:fillViewport="true"> 

    <HorizontalScrollView 
        android:id="@+id/horizontalView" 
        android:layout_height="wrap_content"     
        android:scrollbars="horizontal|vertical" 
        android:layout_width="wrap_content"     
        android:layout_marginTop="5dip">

        <TableLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/tlGridTable" >   
        </TableLayout>
    </HorizontalScrollView>
   </ScrollView>
 </LinearLayout>

问题这对于3个片段加载大约需要10秒钟,因此用户在实际加载活动之前会获得黑屏10秒.我怎么能避免呢？运行在AsyncTask中填充表的所有过程将使我的ViewPager活动加载更快？甚至可以做到吗？

更新：
大部分时间都花费在填充/创建TableLayout上.如果从服务器收到大量数据,则需要创建大量TextView并在TableLayout中设置它们.

更新#2：
好吧,我正在消除这个问题,因为我理解我的需求(整个视图的水平和垂直滚动)我必须使用TableLayout,所以我需要等待这一次加载它.但是我需要找到一种方法来加载片段中的数据,至少在用户知道正在填充数据的情况下(显示适当的Dialog).在我开始片段初始化之前,我试图在ViewPager的onCreate中放置一个对话框,但由于某种原因它没有显示,我只看到黑色屏幕,直到片段被加载.

更新：

请参阅上一个问题,因为我知道无法确定加载时间：

问题：
有没有办法创建一个几乎为空的片段的ViewPager(每个片段只有一个单独的标题),将它们呈现给用户,然后,在活动已经加载并且可见(并且不显示黑屏)之后,呈现一个在显示对话框时对话框并填充片段？

任何帮助,将不胜感激.

谢谢.

解决方法

由于您使用了寻呼机,因此在启动活动时只加载第一个片段.
使用可见的进度条创建初始片段视图,并隐藏表并仅在切换到该片段时加载数据.

在活动中使用

mPager.setOnPageChangeListener(new OnPageChangeListener() {

            @Override
            public void onPageSelected(int position) {
                Fragment f = mAdapter.getFragment(mPager.getCurrentItem());
                f.loadData(); // when you finish loading the data,hide the progress bar and show the table

            }

            @Override
            public void onPageScrolled(int position,float positionOffset,int positionOffsetPixels) {

            }

            @Override
            public void onPageScrollStateChanged(int state) {
            }
        });

要使用mAdapter.getFragment(),请从以下位置继承适配器：

public abstract class SmartFragmentPagerAdapter extends FragmentPagerAdapter{

    private SparseArray<String> mFragmentTags;
    private FragmentManager mFragmentManager;

    public SmartFragmentPagerAdapter(FragmentManager fragmentManager) {
        super(fragmentManager);
        mFragmentManager = fragmentManager;
        mFragmentTags = new SparseArray<String>();
    }

    @Override
    public Object instantiateItem(ViewGroup container,int position) {
        Object obj = super.instantiateItem(container,position);
        if (obj instanceof Fragment) {
            // record the fragment tag here.
            Fragment f = (Fragment) obj;
            String tag = f.getTag();
            mFragmentTags.put(position,tag);
        }
        return obj;
    }

    public Fragment getFragment(int position) {
        String tag = mFragmentTags.get(position);
        if (tag == null)
            return null;
        return mFragmentManager.findFragmentByTag(tag);
    }

    public FragmentManager getFragmentManager(){
        return mFragmentManager;
    }

}

android – 包含TableLayouts的片段的ViewPager加载缓慢：

解决方法

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