使用Scrollview和LinearLayout动态添加布局

• 使用Scrollview 和LinearLayout动态添加布局
• 焦点位置不变，列表实现滚动

1. 放置ScrollView的布局文件，LinearLayout里的paddingBottom 和 paddingTop 是为了在显示的列表的顶部和底部留下空白，可根据需要调整其布局；

2. Java代码，动态生成ScrollView中的布局，这个添加里一个linearLayout，里面包含一个ImageView和一个TextView，设置它们的属性，最后处理LinearLayout的点击事件；

    private LinearLayout llChannelList;
    private ScrollView svChannel;
    private int lastSelectIndex;
    
    /**
     * 动态生成的布局
     */
    llChannelList = (LinearLayout) this.findViewById(R.id.ll_channel_list);
    svChannel = (ScrollView) this.findViewById(R.id.sv_channel);
    
    lastSelectIndex = channelPos;
    
    for (int i = 0; i < ConstUtils.channelNames.length; i++) {
        LinearLayout linearLayout = new LinearLayout(this);
        linearLayout.setOrientation(LinearLayout.VERTICAL);
        linearLayout.setPadding(10, 10, 10, 10);
        linearLayout.setGravity(Gravity.CENTER_HORIZONTAL);
        if (i == lastSelectIndex) {
            linearLayout.setBackgroundResource(R.drawable.bg_list_selected);
            svChannel.post(new Runnable() {
                @Override
                public void run() {
                    svChannel.smoothScrollTo(0, lastSelectIndex * ScreenUtil.dp2px(context, 200));
                }
            });
        }

        ImageView imageView = new ImageView(this);
        int imageWidth = ScreenUtil.dp2px(context, 140);
        int imageHeight = ScreenUtil.dp2px(context, 140);
        imageView.setLayoutParams(new LinearLayout.LayoutParams(imageWidth, imageHeight));
        imageView.setPadding(10, 10, 10, 10);
        imageView.setImageResource(ConstUtils.channelImgWhite[i]);
    
        TextView textView = new TextView(this);
        textView.setTextSize(30);
        textView.setTextColor(Color.WHITE);
        textView.setGravity(Gravity.CENTER_HORIZONTAL);
        textView.setText(ConstUtils.channelNames[i]);
    
        linearLayout.addView(imageView);
        linearLayout.addView(textView);
        llChannelList.addView(linearLayout);
    
        final int pos = i;
        linearLayout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                itemClickAction(pos);
            }
        });
    }
    
    /**
     * 处理动态布局每一条linearLayout的点击事件
     *
     * @param pos 点击位置
     */
    private void itemClickAction(int pos) {
        svChannel.smoothScrollTo(0, pos * ScreenUtil.dp2px(context, 200));
        ((LinearLayout) llChannelList.getChildAt(lastSelectIndex)).setBackgroundColor(Color.TRANSPARENT);
        ((LinearLayout) llChannelList.getChildAt(pos)).setBackgroundResource(R.drawable.bg_list_selected);
        lastSelectIndex = pos;
    
        channelPos = pos;
    
    // do something
    }

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附：

1. 静态常量值

public static final int[] channelImgWhite = {R.drawable.ic_white_movies, R.drawable.ic_white_funny,
        R.drawable.ic_white_random, R.drawable.ic_white_foods,
        R.drawable.ic_white_cartoon, R.drawable.ic_white_lady, R.drawable.ic_white_car};
public static final String[] channelNames = {"频道名称1", "频道名称2", "频道名称3", "频道名称4",
        "频道名称5", "频道名称6", "频道名称7"};

2. ScreenUtil屏幕大小及单位计算的工具类，见 ScreenUtil 屏幕大小及单位计算的工具类

3. channelPos是本人项目中使用的变量，想要选定第几条就赋相应的值；

4. R.drawable.bg_list_selected 是一张Item被选定时的背景图片，替换为所需资源即可；

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注意：

在第一次进入时，直接使用smoothScrollTo( ); 无法直接滚到所期望的位置，使用如下代码即可解决。

    svChannel.post(new Runnable() {
                @Override
                public void run() {
                    svChannel.smoothScrollTo(0, lastSelectIndex * ScreenUtil.dp2px(context, 200));
                }
            });