我知道Google的人要求我们不要在一个可滚动视图中再放入另一个可滚动视图,但他们有任何官方声明直接指示我们不这样做吗?
我知道Google的人要求我们不要在一个可滚动视图中再放入另一个可滚动视图,但他们有任何官方声明直接指示我们不这样做吗?
试试这个
注意: 这里的parentScrollView
指的是外部滚动视图,而childScrollView
指的是内部滚动视图。
parentScrollView.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
Log.v(TAG, "PARENT TOUCH");
findViewById(R.id.child_scroll).getParent()
.requestDisallowInterceptTouchEvent(false);
return false;
}
});
childScrollView.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
Log.v(TAG, "CHILD TOUCH");
// Disallow the touch request for parent scroll on touch of child view
v.getParent().requestDisallowInterceptTouchEvent(true);
return false;
}
});
这个足够接近吗?
不要在ListView中使用HorizontalScrollView,因为ListView会自己处理滚动。最重要的是,这样做会破坏ListView处理大型列表的所有优化,因为它有效地强制ListView显示其整个项目列表以填充HorizontalScrollView提供的无限容器。
http://developer.android.com/reference/android/widget/HorizontalScrollView.html
更新:
如果你被迫使用两个维度的滚动视图,可以考虑使用这个: 这篇博客 of blog.gorges.us/2010/06/android-two-dimensional-scrollview/
我没有用过这个,但可能是一个合理的方法。
Atul Bhardwaj的答案是正确的方法。但是如果有人需要将其应用到一个ScrollView中,而您对父级的控制较少,我认为以下方法就足够灵活,并且它就是应该工作的方式:
private void makeMyScrollSmart() {
myScroll.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View __v, MotionEvent __event) {
if (__event.getAction() == MotionEvent.ACTION_DOWN) {
// Disallow the touch request for parent scroll on touch of child view
requestDisallowParentInterceptTouchEvent(__v, true);
} else if (__event.getAction() == MotionEvent.ACTION_UP || __event.getAction() == MotionEvent.ACTION_CANCEL) {
// Re-allows parent events
requestDisallowParentInterceptTouchEvent(__v, false);
}
return false;
}
});
}
private void requestDisallowParentInterceptTouchEvent(View __v, Boolean __disallowIntercept) {
while (__v.getParent() != null && __v.getParent() instanceof View) {
if (__v.getParent() instanceof ScrollView) {
__v.getParent().requestDisallowInterceptTouchEvent(__disallowIntercept);
}
__v = (View) __v.getParent();
}
}
该函数的作用是为 myScroll
添加一个触摸监听器,在子元素开始触摸时禁用父元素的触摸截获功能,当触摸实际结束时再重新启用。您不需要引用父 ScrollView
,也不必是直接的父级... 它会遍历显示列表直到找到它。
在我看来,这两种方式兼得。
parentScroll.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
v.getParent().requestDisallowInterceptTouchEvent(false);
return false;
}
});
aChildScrollView.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event)
{
v.getParent().requestDisallowInterceptTouchEvent(shouldRequestDisallowIntercept((ViewGroup) v, event));
return false;
}
});
aListView.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
v.getParent().requestDisallowInterceptTouchEvent(shouldRequestDisallowIntercept((ViewGroup) v, event));
return false;
}
});
步骤3 - 下面是正确功能所需的必要魔术方法
protected boolean shouldRequestDisallowIntercept(ViewGroup scrollView, MotionEvent event) {
boolean disallowIntercept = true;
float yOffset = getYOffset(event);
if (scrollView instanceof ListView) {
ListView listView = (ListView) scrollView;
if (yOffset < 0 && listView.getFirstVisiblePosition() == 0 && listView.getChildAt(0).getTop() >= 0) {
disallowIntercept = false;
}
else if (yOffset > 0 && listView.getLastVisiblePosition() == listView.getAdapter().getCount() - 1 && listView.getChildAt(listView.getChildCount() - 1).getBottom() <= listView.getHeight()) {
disallowIntercept = false;
}
}
else {
float scrollY = scrollView.getScrollY();
disallowIntercept = !((scrollY == 0 && yOffset < 0) || (scrollView.getHeight() + scrollY == scrollView.getChildAt(0).getHeight() && yOffset >= 0));
}
return disallowIntercept;
}
protected float getYOffset(MotionEvent ev) {
final int historySize = ev.getHistorySize();
final int pointerCount = ev.getPointerCount();
if (historySize > 0 && pointerCount > 0) {
float lastYOffset = ev.getHistoricalY(pointerCount - 1, historySize - 1);
float currentYOffset = ev.getY(pointerCount - 1);
float dY = lastYOffset - currentYOffset;
return dY;
}
return 0;
}
我认为他们有官方声明,指示我们不要这样做,尽管我在笔记中找不到。当我试图在列表活动中拥有一个滚动视图时,我知道我发现了这样的声明。我认为实际上Android UI系统处理嵌套可滚动视图存在逻辑焦点“漏洞”,这可能应该更好地被检测并传达给开发人员。但我的建议是……
最终考虑用户体验,最好考虑单个可滚动视图。这就像在HTML页面内部有滚动条;它可能是合法的,但这是一个可怕的用户体验。
parentScrollView.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
Utils.showLog("PARENT TOUCH");
findViewById(R.id.activity_mesh_child_scrollView).getParent().requestDisallowInterceptTouchEvent(false);
return false;
}
});
childScrollView.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
Utils.showLog("CHILD TOUCH");
// Disallow the touch request for parent scroll on touch of child view
v.getParent().requestDisallowInterceptTouchEvent(true);
return false;
}
});
https://developer.android.com/reference/android/support/v4/widget/NestedScrollView.html
我没有找到任何关于这个的例子,所以我写的只是猜测它做什么及其用途。
Android支持v4库中有一个名为NestedScrollView的类。
这里,我创建了一个与ScrollView相关的示例项目。其中一个视图可以双向滚动。快来看看吧:
MainActivity.java -
package com.example.dev_task_193_scrollview;
import com.example.dev_task_196_scrollview.R;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.HorizontalScrollView;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.ScrollView;
import android.widget.Toast;
public class MainActivity extends Activity implements View.OnClickListener{
ImageView imageView1,imageView2,imageView3,IVimage1,IVimage2,IVimage3,IVimage4,IVimage5,IVimage6;
ListView listView1,listView2;
HorizontalScrollView horizontalScrollView1,horizontalScrollView2;
ScrollView parentScrollView, scrollView1;
RelativeLayout relativeLayout1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String[] values = new String[] { "Android", "iPhone", "WindowsMobile",
"Blackberry", "WebOS", "Ubuntu", "Windows7", "Max OS X",
"Linux", "OS/2", "Ubuntu", "Windows7", "Max OS X", "Linux",
"OS/2", "Ubuntu", "Windows7", "Max OS X", "Linux", "OS/2",
"Android", "iPhone", "WindowsMobileWindowsMobileWindowsMobileWindowsMobile" };
relativeLayout1 = (RelativeLayout) findViewById(R.id.relativeLayout1);
imageView1 = (ImageView) findViewById(R.id.imageView1);
imageView1.setBackgroundResource(R.drawable.info);
imageView2 = (ImageView) findViewById(R.id.imageView2);
imageView2.setBackgroundResource(R.drawable.info);
imageView3 = (ImageView) findViewById(R.id.imageView3);
imageView3.setBackgroundResource(R.drawable.info);
listView1 = (ListView) findViewById(R.id.listView1);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
R.layout.list_item, values);
listView1.setAdapter(adapter);
listView2 = (ListView) findViewById(R.id.listView2);
ArrayAdapter<String> adapter1 = new ArrayAdapter<String>(this,
R.layout.list_item, values);
listView2.setAdapter(adapter1);
parentScrollView = (ScrollView) findViewById(R.id.parentScrollView);
scrollView1 = (ScrollView) findViewById(R.id.scrollView1);
horizontalScrollView1 = (HorizontalScrollView) findViewById(R.id.horizontalScrollView1);
horizontalScrollView2 = (HorizontalScrollView) findViewById(R.id.horizontalScrollView2);
IVimage1 = (ImageView) findViewById(R.id.IVimage1);
IVimage2 = (ImageView) findViewById(R.id.IVimage2);
IVimage3 = (ImageView) findViewById(R.id.IVimage3);
IVimage4 = (ImageView) findViewById(R.id.IVimage4);
IVimage5 = (ImageView) findViewById(R.id.IVimage5);
IVimage6 = (ImageView) findViewById(R.id.IVimage6);
scrollView1.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event)
{
// Disallow the touch request for parent scroll on touch of child view
parentScrollView.requestDisallowInterceptTouchEvent(true);
return false;
}
});
horizontalScrollView1.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event)
{
// Disallow the touch request for parent scroll on touch of child view
parentScrollView.requestDisallowInterceptTouchEvent(true);
return false;
}
});
listView1.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event)
{
// Disallow the touch request for parent scroll on touch of child view
parentScrollView.requestDisallowInterceptTouchEvent(true);
return false;
}
});
listView1.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Toast.makeText(getApplicationContext(), "Clicked "+parent.getItemAtPosition(position).toString(), Toast.LENGTH_SHORT).show();
}
});
listView2.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Toast.makeText(getApplicationContext(), "Clicked "+parent.getItemAtPosition(position).toString(), Toast.LENGTH_SHORT).show();
}
});
listView2.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event)
{
// Disallow the touch request for parent scroll on touch of child view
parentScrollView.requestDisallowInterceptTouchEvent(true);
return false;
}
});
horizontalScrollView2.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event)
{
// Disallow the touch request for parent scroll on touch of child view
parentScrollView.requestDisallowInterceptTouchEvent(true);
return false;
}
});
/*imageView1.setOnClickListener(this);
imageView2.setOnClickListener(this);
imageView3.setOnClickListener(this);*/
IVimage1.setOnClickListener(this);
IVimage2.setOnClickListener(this);
IVimage3.setOnClickListener(this);
IVimage4.setOnClickListener(this);
IVimage5.setOnClickListener(this);
IVimage6.setOnClickListener(this);
imageView1.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event)
{
// Disallow the touch request for parent scroll on touch of child view
parentScrollView.requestDisallowInterceptTouchEvent(true);
Toast.makeText(getApplicationContext(), "Clicked "+v.getTag(), Toast.LENGTH_SHORT).show();
return false;
}
});
imageView2.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event)
{
// Disallow the touch request for parent scroll on touch of child view
parentScrollView.requestDisallowInterceptTouchEvent(true);
Toast.makeText(getApplicationContext(), "Clicked "+v.getTag(), Toast.LENGTH_SHORT).show();
return false;
}
});
imageView3.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event)
{
// Disallow the touch request for parent scroll on touch of child view
parentScrollView.requestDisallowInterceptTouchEvent(true);
Toast.makeText(getApplicationContext(), "Clicked "+v.getTag(), Toast.LENGTH_SHORT).show();
return false;
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public void onClick(View v) {
switch(v.getId()){
case R.id.imageView1:
Toast.makeText(getApplicationContext(), "Clicked "+v.getTag(), Toast.LENGTH_SHORT).show();
break;
case R.id.imageView2:
Toast.makeText(getApplicationContext(), "Clicked "+v.getTag(), Toast.LENGTH_SHORT).show();
break;
case R.id.imageView3:
Toast.makeText(getApplicationContext(), "Clicked "+v.getTag(), Toast.LENGTH_SHORT).show();
break;
case R.id.IVimage1:
Toast.makeText(getApplicationContext(), "Clicked "+v.getTag(), Toast.LENGTH_SHORT).show();
break;
case R.id.IVimage2:
Toast.makeText(getApplicationContext(), "Clicked "+v.getTag(), Toast.LENGTH_SHORT).show();
break;
case R.id.IVimage3:
Toast.makeText(getApplicationContext(), "Clicked "+v.getTag(), Toast.LENGTH_SHORT).show();
break;
case R.id.IVimage4:
Toast.makeText(getApplicationContext(), "Clicked "+v.getTag(), Toast.LENGTH_SHORT).show();
break;
case R.id.IVimage5:
Toast.makeText(getApplicationContext(), "Clicked "+v.getTag(), Toast.LENGTH_SHORT).show();
break;
case R.id.IVimage6:
Toast.makeText(getApplicationContext(), "Clicked "+v.getTag(), Toast.LENGTH_SHORT).show();
break;
}
// TODO Auto-generated method stub
}
}
activity_main.xml -
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/parentScrollView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_marginBottom="5dp"
android:layout_marginLeft="5dp"
android:layout_marginRight="5dp"
android:layout_marginTop="5dp"
android:background="@drawable/login_bg" >
<RelativeLayout
android:id="@+id/relativeLayout1"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<ScrollView
android:id="@+id/scrollView1"
android:layout_width="fill_parent"
android:layout_height="300dp" >
<HorizontalScrollView
android:id="@+id/horizontalScrollView1"
android:layout_width="match_parent"
android:layout_height="300dp"
android:fillViewport="false" >
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:background="@drawable/bg" >
<ImageView
android:id="@+id/imageView1"
android:layout_width="300dp"
android:layout_height="400dp"
android:tag="imageView1" />
<ImageView
android:id="@+id/imageView2"
android:layout_width="300dp"
android:layout_height="400dp"
android:layout_toRightOf="@+id/imageView1"
android:tag="imageView2" />
<ImageView
android:id="@+id/imageView3"
android:layout_width="300dp"
android:layout_height="400dp"
android:layout_toRightOf="@+id/imageView2"
android:tag="imageView3" />
</RelativeLayout>
</HorizontalScrollView>
</ScrollView>
<ListView
android:id="@+id/listView1"
android:layout_width="500dp"
android:layout_height="400dp"
android:layout_below="@+id/scrollView1"
android:layout_centerHorizontal="true"
android:layout_marginTop="5dp"
android:background="@drawable/ic_launcherwrweq" >
</ListView>
<HorizontalScrollView
android:id="@+id/horizontalScrollView2"
android:layout_width="300dp"
android:layout_height="wrap_content"
android:layout_below="@+id/listView1"
android:layout_centerHorizontal="true"
android:layout_gravity="center"
android:layout_marginTop="5dp"
android:background="@drawable/claim_detail_header_bg"
android:fillViewport="true" >
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<ImageView
android:id="@+id/IVimage1"
android:layout_width="125dp"
android:layout_height="125dp"
android:padding="15dp"
android:src="@drawable/a"
android:tag="a" >
</ImageView>
<ImageView
android:id="@+id/IVimage2"
android:layout_width="125dp"
android:layout_height="125dp"
android:padding="15dp"
android:src="@drawable/b"
android:tag="b" >
</ImageView>
<ImageView
android:id="@+id/IVimage3"
android:layout_width="125dp"
android:layout_height="125dp"
android:padding="15dp"
android:src="@drawable/c"
android:tag="c" >
</ImageView>
<ImageView
android:id="@+id/IVimage4"
android:layout_width="125dp"
android:layout_height="125dp"
android:padding="15dp"
android:src="@drawable/g"
android:tag="g" >
</ImageView>
<ImageView
android:id="@+id/IVimage5"
android:layout_width="125dp"
android:layout_height="125dp"
android:padding="15dp"
android:src="@drawable/e"
android:tag="e" >
</ImageView>
<ImageView
android:id="@+id/IVimage6"
android:layout_width="125dp"
android:layout_height="125dp"
android:padding="15dp"
android:src="@drawable/f"
android:tag="f" >
</ImageView>
</LinearLayout>
</HorizontalScrollView>
<ListView
android:id="@+id/listView2"
android:layout_width="500dp"
android:layout_height="400dp"
android:layout_below="@+id/horizontalScrollView2"
android:layout_centerHorizontal="true"
android:layout_marginTop="5dp"
android:background="@drawable/ic_launcherwrweq" >
</ListView>
</RelativeLayout>
</ScrollView>
list_item.xml(用于ListView) -
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@android:id/text1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_vertical"
android:textSize="25sp"
android:maxLines="1"
android:singleLine="true"
/>
你可以在另一个ScrollView中放置一个ScrollView。只需扩展子ScrollView以覆盖onTouchEvent方法。就像这样
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
public class ChildScrollView extends android.widget.ScrollView {
private int parent_id;
public ChildScrollView(Context context) {
super(context);
}
public ChildScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public ChildScrollView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public boolean onTouchEvent(MotionEvent event){
requestDisallowInterceptTouchEvent(true);
return super.onTouchEvent(event);
}
}