Android ScrollView用法

Android ScrollView用法 今天試著使用了一下Android的滾輪，以下是一個小小的測試，讀取測試文件，主要是使用scrollTo函數和getScrollY()，程序點擊BUTTON按鈕，則向下滾到2222處並顯示。   

package zy.Scroller;  
import java.io.File;  
import java.io.FileInputStream;  
import java.io.IOException;  
import org.apache.http.util.EncodingUtils;  
import android.app.Activity;  
import android.content.Intent;  
import android.os.Bundle;  
import android.view.View;  
import android.widget.ArrayAdapter;  
import android.widget.Button;  
import android.widget.ScrollView;  
import android.widget.TextView;  
import android.widget.Toast;  
   
public class main extends Activity {  
    /** Called when the activity is first created. */  
    final public String DEV_FILE = "/data/data/zy.Scroller/aaa.txt";// 測試文件  
    final String TEXT_ENCODING = "UTF-8";  
    ScrollView sv;  
    TextView tv;  
    public Button test;  
   
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.main);  
        sv = (ScrollView) findViewById(R.id.sv);  
        tv = (TextView) findViewById(R.id.txtView);  
        String str;  
        str = getinfo(DEV_FILE);  
        String[] x;  
        x = str.split("/r");  
        tv.setText(x[0]);  
        int i;  
        for (i = 1; i <= x.length - 1; i++) {  
            tv.append(x[i]);  
        }  
   
        test = (Button) findViewById(R.id.test);  
        test.setOnClickListener(new Button.OnClickListener() {  
            @Override  
            public void onClick(View v) {  
                // TODO Auto-generated method stub  
                sv.scrollTo(0, 2222);  
                DisplayToast(sv.getScrollY() + "");  
   
            }  
   
        });  
   
    }  
   
    protected void onScrollChanged(int l, int t, int oldl, int oldt) {  
        DisplayToast("123");  
    }  
   
    public String getinfo(String path) {  
        File file;  
        String str = "";  
        FileInputStream in;  
        try {  
            // 打開文件file的InputStream  
            file = new File(path);  
            in = new FileInputStream(file);  
            // 將文件內容全部讀入到byte數組  
            int length = (int) file.length();  
            byte[] temp = new byte[length];  
            in.read(temp, 0, length);  
            // 將byte數組用UTF-8編碼並存入display字符串中  
            str = EncodingUtils.getString(temp, TEXT_ENCODING);  
            // 關閉文件file的InputStream  
   
            in.close();  
        } catch (IOException e) {  
   
            DisplayToast(e.toString());  
   
        }  
        return str;  
    }  
   
    public void DisplayToast(String str) {  
        Toast.makeText(this, str, Toast.LENGTH_SHORT).show();  
    }  
}