这是我在模拟器和我的 Galaxy s 上运行的一个工作示例。基本上有两个按钮可以将文本添加到底部文本视图，这取决于您的设备大小，只有其中的第二个应该可以用于查看自动滚动。正在编辑的文本视图使用 ontextchangedlistener 在其文本更改之前检查滚动位置，然后在文本更改后在适当的位置调用延迟（因此屏幕可以使用附加文本更新）自动滚动。
布局xml如下：
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/scrollmain">
<RelativeLayout
android:id="@+id/mainRelative"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="@+id/titleText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Welcome to the scrolling test application!" />
<Button
android:id="@+id/firstTextAddButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/titleText"
android:text="Click me to add text to the textview below without scrolling"/>
<Button
android:id="@+id/secondTextAddButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/firstTextAddButton"
android:layout_marginTop="380dp"
android:text="Click me to add text to the textview below and scroll (if you are currently scrolled all the way to the bottom)"/>
<TextView
android:id="@+id/textToEdit"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/secondTextAddButton"
android:textSize="18sp"
android:text="Some text to get us started."/>
/>
</RelativeLayout>
</ScrollView>
活动代码如下：
package code.example.scrollingontextchange;
import android.os.Bundle;
import android.os.Handler;
import android.app.Activity;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.RelativeLayout;
import android.widget.ScrollView;
import android.widget.TextView;
public class MainActivity extends Activity {
private int scroll_pos;
private int maxScrollPosition;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView tv = (TextView)findViewById(R.id.textToEdit);
tv.addTextChangedListener(new TextWatcher(){
@Override
public void afterTextChanged(Editable s) {
if(scroll_pos == maxScrollPosition)
{
Handler h = new android.os.Handler()
{
@Override
public void handleMessage(android.os.Message msg)
{
switch(msg.what)
{
case 0 :
try {
Thread.sleep(500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ScrollView scrll = (ScrollView)findViewById(R.id.scrollmain);
scrll.fullScroll(ScrollView.FOCUS_DOWN);
break;
default :
break;
}
}
};
h.sendEmptyMessage(0);
}
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
ScrollView scrll = (ScrollView)findViewById(R.id.scrollmain);
RelativeLayout rl = (RelativeLayout)findViewById(R.id.mainRelative);
scroll_pos = scrll.getScrollY();
maxScrollPosition = rl.getHeight() - scrll.getHeight();
}
@Override
public void onTextChanged(CharSequence s, int start, int before,
int count) {
// TODO Auto-generated method stub
}
});
OnClickListener addTextOnClick = new OnClickListener() {
@Override
public void onClick(View v) {
TextView tv = (TextView)findViewById(R.id.textToEdit);
tv.setText(tv.getText() + "\nA long time ago, in a galaxy s far far away............");
}
};
Button b = (Button)findViewById(R.id.firstTextAddButton);
b.setOnClickListener(addTextOnClick);
Button b2 = (Button)findViewById(R.id.secondTextAddButton);
b2.setOnClickListener(addTextOnClick);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
希望这可以帮助。