我正在编写一个操作文本的程序。 我需要能够以编程方式将文本滚动到某个位置。 我已经部分实现了它，但问题在于它并不总是有效，
有时不起作用的情况如下：
以下是我需要滚动的视图布局：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ScrollView
android:id="@+id/ScrollView02"
android:layout_height="fill_parent"
android:layout_width="fill_parent">
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/layoutAllText"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView
android:id="@+id/textSanskrit"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="17dip"
android:gravity="center_vertical|center_horizontal"
android:scrollbars="vertical"
/>
<TextView
android:id="@+id/textTranslit"
android:gravity="center_vertical|center_horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="15dip"
android:scrollbars="vertical"
/>
<TextView
android:id="@+id/textTransl1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="15dip"
android:scrollbars="vertical"
/>
<EditText
android:id="@+id/textTransl2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="17dip"
android:paddingLeft="10px"
android:paddingRight="6px"
android:textColor="@color/green"
android:scrollbars="vertical"
android:editable = "false"
android:background = "#000000"
/>
<EditText
android:id="@+id/textComment"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="17dip"
android:paddingLeft="10px"
android:paddingRight="6px"
android:scrollbars="vertical"
android:editable = "false"
android:textColor = "@android:color/white"
android:background = "#000000"
/>
</LinearLayout>
</ScrollView>
</LinearLayout>
这是活动的摘录，显示了要滚动的文本：
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Central.applySharedTheme(this);
mExtras = getIntent().getExtras();
mCurrBookID = mExtras.getString("BookID");
mCurrChapterNum = mExtras.getString("ChapterNum");
mCurrTextNum = mExtras.getString("TextNum");
mTranslateMode = mExtras.getBoolean("TranslateMode");
setContentView(R.layout.text_disp_basic);
detector = new SimpleGestureFilter(this,this);
mTextScroll=(ScrollView) findViewById(R.id.ScrollView02);
mGitaDB=Central.mDB;
String q="("+mGitaDB.COL_TXT_BOOK_ID+"='"+mCurrBookID+"' AND "+mGitaDB.COL_TXT_CHAPTER_NUM+"='"+mCurrChapterNum+"' AND "+mGitaDB.COL_TXT_TEXT_NUM+"='"+mCurrTextNum+"')";
mCursor = mGitaDB.getdb().query(mGitaDB.TEXTS_TABLE, null, q, null, null, null, null);
Typeface face=Typeface.createFromAsset(getAssets(), "Sanskrit2003.ttf");
mtxtSanskritView=(TextView) findViewById(R.id.textSanskrit);
mtxtTranslitView =(TextView) findViewById(R.id.textTranslit);
mtxtTransl1View =(TextView) findViewById(R.id.textTransl1);
mtxtTransl2View =(TextView) findViewById(R.id.textTransl2);
mtxtComment=(TextView) findViewById(R.id.textComment);
mtxtSanskritView.setTypeface(face);
}
public void onStart() {
super.onStart();
if (mCursor.moveToFirst()) FillTextData();
ShowSanskrit();
getScrollPos();
Log.v("SCROLL", "onStart - mScrollPercentage="+String.valueOf(mScrollPercentage));
ScrollTextToCurrentPercentage("OnStart");
}
public void onPause() {
super.onPause();
mbFirstCall=true;
float scroll = getScrollPos(mTextScroll);
Log.v("SCROLL", "onPause - getScrollPos="+String.valueOf(scroll));
SharedPreferences LastOpenedScreen = getSharedPreferences(Central.SHARED_PREFS_LASTSCREEN, MODE_PRIVATE);
SharedPreferences.Editor prefEditor = LastOpenedScreen.edit();
prefEditor.putString(Central.SP_LASTSCREEN_BOOKID, mCurrBookID);
if(!mTranslateMode){
prefEditor.putString(Central.SP_LASTSCREEN_BCHAPTER+mCurrBookID, mCurrChapterNum);
prefEditor.putString(Central.SP_LASTSCREEN_BTEXT+mCurrBookID, mCurrTextNum);
prefEditor.putFloat(Central.SP_LASTSCREEN_SCROLL, scroll);
Log.v("SCROLL", "onPause - saved scroll="+String.valueOf(scroll));
}
else
{
prefEditor.putFloat("TranslateScrollPercentage", scroll);
Log.v("SCROLL", "onPause - Before Translate scroll="+String.valueOf(scroll));
}
prefEditor.commit();
}
public void onResume()
{
super.onResume();
FillTextData();
getScrollPos();
Log.v("SCROLL", "onResume - mScrollPercentage="+String.valueOf(mScrollPercentage));
ScrollTextToCurrentPercentage("onResume");
}
private void getScrollPos()
{
String sLastBookID, sLastChapter, sLastText;
SharedPreferences LastOpenedScreen = getSharedPreferences(Central.SHARED_PREFS_LASTSCREEN, MODE_PRIVATE);
sLastBookID=LastOpenedScreen.getString(Central.SP_LASTSCREEN_BOOKID, "");
mScrollPercentage=this.ScrollToFloat(mExtras.getLong("Scroll", 0));
if (sLastBookID.equalsIgnoreCase(this.mCurrBookID))
{
//last chapter and text of this book
sLastChapter=LastOpenedScreen.getString(Central.SP_LASTSCREEN_BCHAPTER+mCurrBookID, "");
sLastText=LastOpenedScreen.getString(Central.SP_LASTSCREEN_BTEXT+mCurrBookID, "");
//if this chapter and text are the same as saved last text and chapter, then set scroll
if (sLastChapter.equals(this.mCurrChapterNum) && sLastText.equals(this.mCurrTextNum) )
mScrollPercentage=LastOpenedScreen.getFloat(Central.SP_LASTSCREEN_SCROLL, 0);
}
//if this activity is called after translate button pressed
if (mTranslateMode)
{
mScrollPercentage=LastOpenedScreen.getFloat("TranslateScrollPercentage", 0);
Log.v("SCROLL", "getScrollPos - mTranslateMode - mScrollPercentage="+String.valueOf(mScrollPercentage));
}
Log.v("SCROLL", "getScrollPos - mScrollPercentage="+String.valueOf(mScrollPercentage));
}
private void ScrollTextToCurrentPercentage(String sCallOrigin)
{
//scroll to mScrollPercentage position
mbFirstCall=true;
mTextScroll=(ScrollView) findViewById(R.id.ScrollView02);
int iHeight=mTextScroll.getChildAt(0).getHeight();
Log.v("SCROLL", "ScrollTextToCurrentPercentage call. height=:"+String.valueOf(iHeight));
if (iHeight!=0)
{
int y=(int)(iHeight*mScrollPercentage);
mTextScroll.scrollBy(0, y);
Log.v("SCROLL", "ScrollText scrolled to:"+String.valueOf(y));
}
else
{
ViewTreeObserver vto = mTextScroll.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
public void onGlobalLayout() {
int y=(int)(mTextScroll.getChildAt(0).getHeight()*mScrollPercentage);
if (mbFirstCall){
mTextScroll.scrollBy(0, y);
mbFirstCall=false;
Log.v("SCROLL", "ScrollTextToCurrentPercentage scrolled to:"+String.valueOf(y));
}
}
});
}
}
http://www.ljplus.ru/img4/n/e/nepalec/screenshot.jpg
在此屏幕截图中，您可以看到程序滚动到正确的保存位置，但是，屏幕上的实际位置是不同的。 Toast显示实际滚动为8％，而保存的滚动为26％。 LogCat中的最后一行显示mTextScroll.scrollBy（0，y）; ScrollTextToCurrentPercentage中的行已执行。
我被困在上面，你能帮帮我吗，也许是因为缺乏知识和经验，我做错事。
