Android ScrollView与ListView,GridView共处冲突解决方案

Android ScrollView与ListView,GridView共存冲突解决方案

我们在真实项目中通常会遇到ListView或者GridView嵌套在ScrollView中问题。但是做的时候会发现，一旦两者进行嵌套，即会发生冲突。得不到我们希望的效果。由于ListView和GridView本身都继承于ScrollView，一旦在ScrollView中嵌套ScrollView，那么里面的ScrollView高度计算就会出现问题。我们也就无法得到想要的效果。下面进入正题，我们将分别讨论ScrollView中嵌套ListView和FGridView的情况：

核心解决方案：重写ListView或者GridView的OnMesure 方法：

@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {// TODO Auto-generated method stubint expandSpec = MeasureSpec.makeMeasureSpec(                 Integer.MAX_VALUE &gt;&gt; 2, MeasureSpec.AT_MOST); super.onMeasure(widthMeasureSpec, expandSpec);}

一、ScrollView中嵌套ListView

BlogScrollViewActivity.java代码：

package com.csdn.blog.scrollview;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.ViewGroup;import android.widget.ArrayAdapter;import android.widget.BaseAdapter;import android.widget.GridView;import android.widget.ImageView;import android.widget.LinearLayout;import android.widget.ListView;import android.widget.ScrollView;import android.widget.LinearLayout.LayoutParams;import android.widget.TextView;public class BlogScrollViewActivity extends Activity {    /** Called when the activity is first created. *///MyGridView  grid;ImageView image;ScrollView scroll;String[] texts=new String[]{"无线","通话设置","声音","显示","位置",                    "应用","账户","隐私权","存储","语言","游戏","娱乐","电影","音乐",                    "辅助功能","日期"};/*ArrayAdapter&lt;String&gt; adapter;*/TestListView list;LinearLayout.LayoutParams lp;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        init();    }    void init(){    list=(TestListView)findViewById(R.id.list);    image=(ImageView)findViewById(R.id.image);    list.setAdapter(new GridAdapter(this));    scroll=(ScrollView)findViewById(R.id.scroll);    scroll.requestChildFocus(image, null);    }    private class GridAdapter extends BaseAdapter{    Activity context;    public GridAdapter(Activity context){    this.context=context;    }@Overridepublic int getCount() {// TODO Auto-generated method stubreturn texts.length;}@Overridepublic Object getItem(int position) {// TODO Auto-generated method stubreturn null;}@Overridepublic long getItemId(int position) {// TODO Auto-generated method stubreturn 0;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {// TODO Auto-generated method stubViewHolder holder=null;if(convertView==null){convertView=context.getLayoutInflater().inflate(R.layout.item, null);holder=new ViewHolder();holder.text=(TextView)convertView.findViewById(R.id.grid_text);convertView.setTag(holder);}else{holder=(ViewHolder)convertView.getTag();}holder.text.setText(texts[position]);return convertView;}class ViewHolder {TextView text;}        }}

TestListView.java代码如下：

package com.csdn.blog.scrollview;import android.content.Context;import android.util.AttributeSet;import android.view.View.MeasureSpec;import android.widget.ListView;public class TestListView extends ListView{public TestListView(Context context) {super(context);// TODO Auto-generated constructor stub}public TestListView(Context context, AttributeSet attrs) {super(context, attrs);// TODO Auto-generated constructor stub}public TestListView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);// TODO Auto-generated constructor stub}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {// TODO Auto-generated method stubint expandSpec = MeasureSpec.makeMeasureSpec(                 Integer.MAX_VALUE &gt;&gt; 2, MeasureSpec.AT_MOST); super.onMeasure(widthMeasureSpec, expandSpec);}}

main.xml代码：

&lt;?xml version="1.0" encoding="utf-8"?&gt;&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical"     android:background="#FFFFFF"    &gt;    &lt;ScrollView        android:layout_height="fill_parent"        android:layout_width="fill_parent"        android:fadingEdgeLength="0dp"        android:scrollbars="none"        android:id="@+id/scroll"&gt;        &lt;LinearLayout            android:layout_height="fill_parent"            android:layout_width="fill_parent"            android:orientation="vertical"            &gt;      &lt;ImageView          android:id="@+id/image"          android:layout_height="150dp"          android:layout_width="fill_parent"          android:padding="2dp"          android:scaleType="centerCrop"          android:src="@drawable/fruit"
          /&gt;      &lt;com.csdn.blog.scrollview.TestListView          android:id="@+id/list"          android:layout_height="fill_parent"          android:layout_width="fill_parent"          android:fadingEdgeLength="0dp"          android:scrollbars="none"          /&gt;        &lt;/LinearLayout&gt;    &lt;/ScrollView&gt;
&lt;/LinearLayout&gt;

效果图如下：

Android ScrollView与ListView,GridView共处冲突解决方案

这里我的布局方式是上面一张图片，下面放置listView。

对于此种布局方式，可以通过另外一种方式避免此问题。由于ListView有addHeadView()方法，那么我们可以直接将上面想加入的View通过 getLayoutInflater().inflate(this,R.layout.***) 加入到ListView的顶部即可。

二、ScrollView中嵌套GridView的解决方案。

ScrollView中嵌套GridView ，最简单的方法就是重写GridView方法，使其在绘制时重新计算GridView高度

MyGridView.java代码如下：

package com.csdn.blog.scrollview;import android.content.Context;import android.util.AttributeSet;import android.widget.GridView;public class MyGridView extends GridView{public MyGridView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);// TODO Auto-generated constructor stub}public MyGridView(Context context, AttributeSet attrs) {super(context, attrs);// TODO Auto-generated constructor stub}public MyGridView(Context context) {super(context);// TODO Auto-generated constructor stub}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {// TODO Auto-generated method stubint expandSpec = MeasureSpec.makeMeasureSpec(                 Integer.MAX_VALUE &gt;&gt; 2, MeasureSpec.AT_MOST);         super.onMeasure(widthMeasureSpec, expandSpec); }}

main.xml代码如下：

&lt;?xml version="1.0" encoding="utf-8"?&gt;&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical"     android:background="#FFFFFF"    &gt;    &lt;ScrollView        android:layout_height="fill_parent"        android:layout_width="fill_parent"        android:fadingEdgeLength="0dp"        android:scrollbars="none"        android:id="@+id/scroll"&gt;        &lt;LinearLayout            android:layout_height="fill_parent"            android:layout_width="fill_parent"            android:orientation="vertical"            &gt;    &lt;ImageView        android:id="@+id/image"        android:layout_height="150dp"        android:layout_width="fill_parent"        android:padding="2dp"        android:scaleType="centerCrop"        android:src="@drawable/fruit"        /&gt;    &lt;com.csdn.blog.scrollview.MyGridView        android:layout_marginTop="10dp"        android:id="@+id/grid"        android:layout_height="fill_parent"        android:layout_width="fill_parent"        android:fadingEdgeLength="0dp"        android:scrollbars="none"        android:numColumns="3"        /&gt;        &lt;/LinearLayout&gt;    &lt;/ScrollView&gt;&lt;/LinearLayout&gt;

主类主要就是GridVIew数据绑定。简单贴下代码：

package com.csdn.blog.scrollview;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.ViewGroup;import android.widget.ArrayAdapter;import android.widget.BaseAdapter;import android.widget.GridView;import android.widget.ImageView;import android.widget.LinearLayout;import android.widget.ListView;import android.widget.ScrollView;import android.widget.LinearLayout.LayoutParams;import android.widget.TextView;public class BlogScrollViewActivity extends Activity {    /** Called when the activity is first created. */MyGridView  grid;ImageView image;ScrollView scroll;String[] texts=new String[]{"无线","通话设置","声音","显示","位置",                    "应用","账户","隐私权","存储","语言","游戏","娱乐","电影","音乐",                    "辅助功能","日期"};ArrayAdapter&lt;String&gt; adapter;LinearLayout.LayoutParams lp;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        init();    }    void init(){    image=(ImageView)findViewById(R.id.image);    grid=(MyGridView)findViewById(R.id.grid);    grid.setAdapter(new GridAdapter(this));    scroll=(ScrollView)findViewById(R.id.scroll);    scroll.requestChildFocus(image, null);    }    private class GridAdapter extends BaseAdapter{    Activity context;    public GridAdapter(Activity context){    this.context=context;    }@Overridepublic int getCount() {// TODO Auto-generated method stubreturn texts.length;}@Overridepublic Object getItem(int position) {// TODO Auto-generated method stubreturn null;}@Overridepublic long getItemId(int position) {// TODO Auto-generated method stubreturn 0;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {// TODO Auto-generated method stubViewHolder holder=null;if(convertView==null){convertView=context.getLayoutInflater().inflate(R.layout.item, null);holder=new ViewHolder();holder.image=(ImageView)convertView.findViewById(R.id.grid_image);holder.text=(TextView)convertView.findViewById(R.id.grid_text);convertView.setTag(holder);}else{holder=(ViewHolder)convertView.getTag();}holder.image.setImageResource(R.drawable.meinv);holder.text.setText(texts[position]);return convertView;}class ViewHolder {ImageView image;TextView text;}        }}

上述代码中 scroll.requestChildFocus(image, null); 此句主要是修复了程序进入时GridView会滑动到顶端的小bug。

效果图如下：

Android ScrollView与ListView,GridView共处冲突解决方案

Android ScrollView与ListView,GridVi

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