Android片段空白

我有一个具有RelativeLayout和ImageView的片段。Android片段空白

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:id="@+id/pagelayout" 
android:layout_below="@layout/toolbar" 
android:layout_width="match_parent" 
android:layout_height="wrap_content" 
android:orientation="vertical" 
android:background="@color/aqua_blue" 
tools:context="MainActivityFragment"> 

<ImageView 
    android:id="@+id/pdfImage" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:background="@android:color/white" 
    android:adjustViewBounds="true" 
    android:scaleType="fitStart"/>

我呈现pdfpage如在onViewCreated图像视图如下的图像和显示。

pageLayout = (RelativeLayout) rootView.findViewById(R.id.pagelayout); 
    //Retain view references. 
    mImageView = (ImageView) rootView.findViewById(R.id.pdfImage);   

    // Show the first page by default. 
    mCurrentPageNum = pdfRenderer.getmCurrentPageNum(); 
    if (mCurrentPageNum == 0) { 
     mCurrentPageNum = 1; 
     pdfRenderer.setmCurrentPageNum(mCurrentPageNum); 
    } 
    showPage(mCurrentPageNum, true, this.activity); 

    //get screen size 
    DisplayMetrics metrics = context.getResources().getDisplayMetrics(); 
    scrwidth = metrics.widthPixels; 
    scrheight = pdfRenderer.getPDFImage().getHeight(); 

    pageControlsList = pdfRenderer.GetPageControls(); 
    if (pageControlsList != null) { 
     if (pageControlsList.size() > 0) { 
      generateControls(); 
      showPage(mCurrentPageNum, true, this.activity); 
     } 
    }

当用户在页面上滑动时，我导航到下一页或上一页。为此，我正在调用Mainactivity的片段中编写的以下函数。

public void Readpage(int index, boolean PdfReload, Activity activity) 
{ 
    //context=activity; 
    //pageLayout = (RelativeLayout) rootView.findViewById(R.id.pagelayout); 
    //mImageView = (ImageView) rootView.findViewById(R.id.pdfImage); 
    showPage(index, true, activity); 
    pageControlsList = pdfRenderer.GetPageControls(); 
    if (pageControlsList != null) { 
     generateControls();    
    } 
}

如果页面中有任何控件并动态生成，则会调用Generatecontrols方法。代码如下（只给出一个样本控件）。

public void generateControls() { 
    //iterate loop to create each control 
     for (Map.Entry<Integer, PageElement> ctrl : pageControlsList.entrySet()) { 
      Integer ctrlKey = ctrl.getKey(); 
      PageElement pageField = ctrl.getValue(); 
      String name = pageField.getName(); 
      int type = pageField.getType(); 


      int pdfw = (int) pdfRenderer.getPage_width(); 
      int pdfh = (int) pdfRenderer.getPage_height(); 

      //get dimensions of the control 
      int left = (int) pageField.getLeft(); 
      int top = (int) pageField.getTop(); 
      int right = (int) pageField.getRight(); 
      int bottom = (int) pageField.getBottom(); 
      int width = (int) pageField.getWidth(); 
      int height = (int) pageField.getHeight(); 

      //calculate dimensions w.r.t. screen size 
      int ctrlW = scrwidth * width/pdfw; 
      int ctrlH = scrheight * height/pdfh; 
      int ctrlLeft = (int) (scrwidth * left)/pdfw; 
      int ctrlTop = (int) (((scrheight * (pdfh - top))/pdfh)); 
      int ctrlRight = (int) (scrwidth * right)/pdfw; 
      int ctrlBottom = (int) (scrheight * bottom/pdfh); 

      //set dimensions of the control with layout parameters 
      RelativeLayout.LayoutParams ctrllp = new RelativeLayout.LayoutParams(ctrlW, ctrlH); 
      ctrllp.setMargins(ctrlLeft, ctrlTop, 0, 0); 


      //generate controls based on the type of control 
      if (type == 2) { //checkbox 
       CheckBox myChkBox = new CheckBox(context); 
       myChkBox.setId(ctrlKey); 
       myChkBox.setFocusable(false); 
       myChkBox.setEnabled(false); 
       if (pageField.ExportValue().contains("Off")) 
        myChkBox.setChecked(false); 
       else 
        myChkBox.setChecked(true); 

       pageLayout.setLayoutParams(ctrllp); 
       pageLayout.addView(myChkBox, ctrllp); 
}

即使第一页包含任何控件，它也能正常工作。一旦我滑动，如果任何其他页面包含控件，然后我只能看到一个空白片段。如果没有控制，那么我可以看到一切正常工作。我尝试了很多方法，但都没有为我工作。请任何帮助。

来源

2017-03-22 dev_P

经过一番R & D我在我的代码中发现了问题。只需在主要活动而不是Fragment中编写代码即可。呈现活动中的控件，但不在片段中。

//to display page controls during appload 
    pageControlsList = pdfRenderer.GetPageControls(); 
    if (pageControlsList != null) { 
     if (pageControlsList.size() > 0) { 
      generateControls(); 
      //fillDefaultDocControls(); 
      mfrg.showPage(pdfRenderer.getmCurrentPageNum(), true, this); 
     } 
    }

只是生成控件并调用片段来显示页面。

来源

2017-04-10 04:47:13

Android片段空白

回答

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