ScrollView的使用详细

谭畅
2023-12-01

滚动视图(ScrollView)是指当拥有很多内容,屏幕显示不完时,需要通过滚动来显示完整的视图。包括水平滚动视图(HorizontalScrollView)和垂直滚动视图(ScrollView)

隐藏滚动条
1、标签属性:android:scrollbars=”none”
2、代码设置:
setHorizontalScrollBarEnabled(false);//隐藏横向ScorollView
setVerticalScrollBarEnabled(false);//隐藏纵向ScorollView

setOnTouchListener的使用:判断ScrollView何时滑动到底部
1、getScorollY()——滚动条滑动的距离
2、getMeasuredHeight()——内容的整体高度,包括隐藏部分
3、getHeight()——显示高度。内容未布满屏幕,2=3;内容大于屏幕,3=屏幕高度,2>3。
4、getChildAt(int i)——获取ScorollView的第i个子控件

scrollTo和scrollBy:控制ScrollView视图的位置

<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"  
    android:orientation="vertical" >  

    <!-- 横向滚动条 -->  
    <!-- <HorizontalScrollView  
        android:id="@+id/horizontalScrollView1"  
        android:layout_width="wrap_content"  
        android:layout_height="match_parent"  
        android:scrollbars="none" >  

        <TextView  
            android:id="@+id/textView1"  
            android:layout_width="wrap_content"  
            android:layout_height="match_parent"  
            android:textSize="22sp" />  
    </HorizontalScrollView> -->  

    <!-- 纵向滚动条 -->  

    <Button  
        android:id="@+id/button1"  
        android:layout_width="match_parent"  
        android:layout_height="wrap_content"  
        android:text="向上" />  

    <Button  
        android:id="@+id/button2"  
        android:layout_width="match_parent"  
        android:layout_height="wrap_content"  
        android:text="向下" />  

    <ScrollView  
        android:id="@+id/scrollView1"  
        android:layout_width="match_parent"  
        android:layout_height="wrap_content"  
        android:scrollbars="none" >  

        <TextView  
            android:id="@+id/textView1"  
            android:layout_width="match_parent"  
            android:layout_height="wrap_content"  
            android:textSize="22sp" />  
    </ScrollView>  

</LinearLayout>  
public class MainActivity extends Activity implements OnClickListener{  
    private Button button1;  
    private Button button2;  
    private TextView textView;  
    private ScrollView scrollView;  

    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  

        button1 = (Button) findViewById(R.id.button1);  
        button2 = (Button) findViewById(R.id.button2);  
        textView = (TextView) findViewById(R.id.textView1);  
        scrollView = (ScrollView) findViewById(R.id.scrollView1);  

        button1.setOnClickListener(this);  
        button2.setOnClickListener(this);  

        //这里是为textView赋值,内容在R.string.text中,测试时最好内容长一些,这里不再贴出。  
        textView.setText(getResources().getString(R.string.text));  
        scrollView.setOnTouchListener(new OnTouchListener() {  

            @TargetApi(Build.VERSION_CODES.HONEYCOMB)  
            @Override  
            public boolean onTouch(View v, MotionEvent event) {  
                // TODO Auto-generated method stub  
                switch (event.getAction()) {  
                //手指抬起  
                case MotionEvent.ACTION_UP:  

                    break;  

                //手指落下  
                case MotionEvent.ACTION_DOWN:  

                    break;  

                //手指滑动  
                case MotionEvent.ACTION_MOVE:  
                    /** 
                     * 1、getScorollY()——滚动条滑动的距离 
                     * 2、getMeasuredHeight()——内容的整体高度,包括隐藏部分 
                     * 3、getHeight()——显示高度。内容未布满屏幕,2=3;内容大于屏幕,3=屏幕高度,2>3。 
                     */  
                    //顶部状态  
                    if(scrollView.getScrollY()<=0){  
                        Log.e(">>>>>>>>>>>>>>", "顶部");  
                        Toast.makeText(MainActivity.this, "顶部", Toast.LENGTH_SHORT).show();  
                    }  

                    //顶部状态  
                    //TextView的总高度<=一屏幕的高度+滚动条的滚动距离(getChildAt(0):第0个子控件)  
                    if(scrollView.getChildAt(0).getMeasuredHeight()<= scrollView.getScrollY() + scrollView.getHeight()){  
                        Log.e(">>>>>>>>>>>>>>", "底部");  
                        Toast.makeText(MainActivity.this, "底部", Toast.LENGTH_SHORT).show();  

                        //在文本中追加内容  
                        textView.append("111111111111111111111");  
                    }  
                    break;  
                }  
                return false;  
            }  
        });  
    }  

    @Override  
    public void onClick(View v) {  
        //scrollTo:以滚动视图起始位置开始计算的  
        //scrollBy:相对前一次的位置,滚动相应的距离  
        switch (v.getId()) {  
        case R.id.button1:  
//          scrollView.scrollTo(0, -30);  
            scrollView.scrollBy(0, -30);  
            break;  

        case R.id.button2:  
//          scrollView.scrollTo(0, -30);  
            scrollView.scrollBy(0, 30);  
            break;  
        }  
    }  
}  

HorizontalScrollView的简单用法

HorizontalScrollView其实是FrameLayout的子类,所以内部只能有一个直接的子View。我们用来做Gallery效果,首选当然是LinearLayout,然后方向设置为水平。
1、布局文件:

<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" >  
        </LinearLayout>  
    </HorizontalScrollView>  

</LinearLayout>  

很简单,就一个HorizontalScrollView内部有个水平方向的LinearLayout
MainActivity:

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.activity_main);  
        mInflater = LayoutInflater.from(this);  
        initData();  
        initView();  

    }  

    private void initData()  
    {  
        mImgIds = new int[] { R.drawable.a, R.drawable.b, R.drawable.c,  
                R.drawable.d, R.drawable.e, R.drawable.f, R.drawable.g,  
                R.drawable.h, R.drawable.l };  
    }  

    private void initView()  
    {  
        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,  
                    mGallery, false);  
            ImageView img = (ImageView) view  
                    .findViewById(R.id.id_index_gallery_item_image);  
            img.setImageResource(mImgIds[i]);  
            TextView txt = (TextView) view  
                    .findViewById(R.id.id_index_gallery_item_text);  
            txt.setText("some info ");  
            mGallery.addView(view);  
        }  
    }  

}  

很简单,我预先准备了一些图片直接放在了Drawble下,然后循环加入HorizontalScrollView的LinearLayout中即可。

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