Android ScrollView用法

时间：2023-03-09 03:19:18
Android ScrollView用法

Android ScrollView用法
今天试着使用了一下Android的滚轮，以下是一个小小的测试，读取测试文件，主要是使用scrollTo函数和getScrollY()，程序点击BUTTON按钮，则向下滚到2222处并显示。

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";// 测试文件

    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 {

            // 打开文件file的InputStream

            file = new File(path);

            in = new FileInputStream(file);

            // 将文件内容全部读入到byte数组

            int length = (int) file.length();

            byte[] temp = new byte[length];

            in.read(temp, 0, length);

            // 将byte数组用UTF-8编码并存入display字符串中

            str = EncodingUtils.getString(temp, TEXT_ENCODING);

            // 关闭文件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();

    }

}

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