Android 實戰(zhàn)簡易教程-第四槍（ScrollView 和 HorizontalScrollView 動態(tài)添加控件并提供事件

一、ScrollView

由于手機屏幕的高度有限，在面對組件要顯示多組信息時，ScrollView 視圖（滾動視圖）可以有效的安排這些組件，瀏覽時可以自動的進(jìn)行滾屏的操作。

ScrollView 視圖的定義格式如下：

<?xml version="1.0" encoding="utf-8"?>
<ScrollView 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/myscroll">
<LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:id="@+id/mylinear" >
</LinearLayout>
</ScrollView>

這里需要注意的是：滾動視圖的使用形式和各個布局管理器的操作形式類似，唯一不同的是所有的布局管理器中均可以包含多個組件，而滾動視圖中只能有一個組件。否則會報錯，可以自行測試！

下面看一下 MainActivity 程序：

package org.lxh.demo;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.Toast;

public class Hello extends Activity {
    String str[] = { "1", "2", "3", "4", "5", "6", "7", "8", };

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState); // 生命周期方法
        super.setContentView(R.layout.main); // 設(shè)置要使用的布局管理器
        LinearLayout linear = (LinearLayout) super.findViewById(R.id.mylinear);// 取得組件
        LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(
                ViewGroup.LayoutParams.FILL_PARENT,
                ViewGroup.LayoutParams.WRAP_CONTENT);// 定義按鈕的布局參數(shù)
        for (int i = 0; i < this.str.length; i++) {
            Button btn = new Button(this);// 創(chuàng)建按鈕組件
            btn.setText(this.str[i]);// 設(shè)置文本
            btn.setId(i);
            linear.addView(btn, param);// 增加組件
            btn.setOnClickListener(new OnClickListenerImpl());

        }

    }

    private class OnClickListenerImpl implements OnClickListener {

        public void onClick(View v) {
            switch (v.getId()) {
            case 0:
                Toast.makeText(Hello.this, "您選擇了按鈕1！", Toast.LENGTH_SHORT)
                        .show();
                break;
            case 1:
                Toast.makeText(Hello.this, "您選擇了按鈕2！", Toast.LENGTH_SHORT)
                        .show();
                break;
            case 2:
                Toast.makeText(Hello.this, "您選擇了按鈕3！", Toast.LENGTH_SHORT)
                        .show();
                break;
            case 3:
                Toast.makeText(Hello.this, "您選擇了按鈕4！", Toast.LENGTH_SHORT)
                        .show();
                break;
            case 4:
                Toast.makeText(Hello.this, "您選擇了按鈕5！", Toast.LENGTH_SHORT)
                        .show();
                break;
            case 5:
                Toast.makeText(Hello.this, "您選擇了按鈕6！", Toast.LENGTH_SHORT)
                        .show();
                break;
            case 6:
                Toast.makeText(Hello.this, "您選擇了按鈕7！", Toast.LENGTH_SHORT)
                        .show();
                break;
            case 7:
                Toast.makeText(Hello.this, "您選擇了按鈕8！", Toast.LENGTH_SHORT)
                        .show();
                break;
            case 8:
                Toast.makeText(Hello.this, "您選擇了按鈕8！", Toast.LENGTH_SHORT)
                        .show();
                break;

            default:
                break;
            }

        }

    }
}

運行實例：

http://wiki.jikexueyuan.com/project/android-in-action/images/8.png" alt="" />

二、HorizontalScrollView

首先定義主布局文件 main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <HorizontalScrollView
        android:layout_width="wrap_content"
        android:layout_height="150dp"
        android:layout_gravity="center_vertical"
        android:background="#AA444444"
        android:scrollbars="none" >

        <LinearLayout
            android:id="@+id/id_gallery"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:orientation="horizontal"
            android:scrollbars="horizontal" >
        </LinearLayout>
    </HorizontalScrollView>

</LinearLayout>

然后定義 activity_index_gallery_item.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="120dp"
    android:layout_height="130dp"
    android:background="@android:color/white" >

    <ImageView
        android:id="@+id/id_index_gallery_item_image"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_margin="5dp"
        android:scaleType="centerCrop" />

    <TextView
        android:id="@+id/id_index_gallery_item_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/id_index_gallery_item_image"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="5dp"
        android:layout_marginTop="5dp"
        android:textColor="#ff0000"
        android:textSize="12dp" />

</RelativeLayout>

MainActivity 程序如下：

package org.yayun.demo;

import android.app.Activity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.Window;
import android.view.View.OnClickListener;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

    private LinearLayout mGallery;
    private int[] mImgIds;
    private LayoutInflater mInflater;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.main);
        mInflater = LayoutInflater.from(this);
        initData();
        initView();

    }

    private void initData()// 初始化數(shù)據(jù)
    {
        mImgIds = new int[] { R.drawable.a, R.drawable.b, R.drawable.c,
                R.drawable.d, R.drawable.e, };
    }

    private void initView()// 填充數(shù)據(jù)
    {

        mGallery = (LinearLayout) findViewById(R.id.id_gallery);

        for (int i = 0; i < mImgIds.length; i++) {

            View view = mInflater.inflate(R.layout.activity_index_gallery_item,// 找到布局文件
                    mGallery, false);
            ImageView img = (ImageView) view
                    .findViewById(R.id.id_index_gallery_item_image);// 找到圖片控件
            img.setImageResource(mImgIds[i]);
            img.setId(i);
            img.setOnClickListener(new OnClickListenerImpl());
            TextView txt = (TextView) view
                    .findViewById(R.id.id_index_gallery_item_text);
            txt.setText("some info ");

            mGallery.addView(view);

        }
    }
    private class OnClickListenerImpl implements OnClickListener{

        public void onClick(View v) {
            switch (v.getId()) {
            case 0:
                Toast.makeText(MainActivity.this, "圖片a", Toast.LENGTH_SHORT).show();
                break;
            case 1:
                Toast.makeText(MainActivity.this, "圖片b", Toast.LENGTH_SHORT).show();
                break;
            case 2:
                Toast.makeText(MainActivity.this, "圖片c", Toast.LENGTH_SHORT).show();
                break;
            case 3:
                Toast.makeText(MainActivity.this, "圖片d", Toast.LENGTH_SHORT).show();
                break;
            case 4:
                Toast.makeText(MainActivity.this, "圖片e", Toast.LENGTH_SHORT).show();
                break;

            default:
                break;
            }

        }

    }

}

運行實例如下：

http://wiki.jikexueyuan.com/project/android-in-action/images/9.png" alt="" />