GridView--scroolview嵌套listview和gridview

2022-07-12 13:04:27

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：

[java]
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    // TODO Auto-generated method stub
    int expandSpec = MeasureSpec.makeMeasureSpec(
               Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);

    super.onMeasure(widthMeasureSpec, expandSpec);
}

一、ScrollView中嵌套ListView

BlogScrollViewActivity.java代码：

[java]
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 {

//  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"};

    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;
        }
        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return texts.length;
        }

        @Override
        public Object getItem(int position) {
            // TODO Auto-generated method stub
            return null;
        }

        @Override
        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return 0;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // TODO Auto-generated method stub
            ViewHolder 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：

[java]
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
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // TODO Auto-generated method stub
        int expandSpec = MeasureSpec.makeMeasureSpec(
                Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);

        super.onMeasure(widthMeasureSpec, expandSpec);
    }

}

main.xml代码：

[html]
<p><?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="<a href="http://schemas.android.com/apk/res/android">http://schemas.android.com/apk/res/android</a>"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    android:background="#FFFFFF"
    >
    <ScrollView
        android:layout_height="fill_parent"
        android:layout_width="fill_parent"
        android:fadingEdgeLength="0dp"
        android:scrollbars="none"
        android:id="@+id/scroll">
        <LinearLayout
            android:layout_height="fill_parent"
            android:layout_width="fill_parent"
            android:orientation="vertical"
            >
      <ImageView
          android:id="@+id/image"
          android:layout_height="150dp"
          android:layout_width="fill_parent"
          android:padding="2dp"
          android:scaleType="centerCrop"
          android:src="@drawable/fruit"</p><p>          />
      <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"
          />
        </LinearLayout>
    </ScrollView></p><p></LinearLayout></p>

效果图如下：

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：

[java]
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
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // TODO Auto-generated method stub
        int expandSpec = MeasureSpec.makeMeasureSpec(
                Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);
        super.onMeasure(widthMeasureSpec, expandSpec);

    }
}

main.xml代码如下：

[java]
<?xml version="1.0" encoding="utf-8"?>
<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"
    >
    <ScrollView
        android:layout_height="fill_parent"
        android:layout_width="fill_parent"
        android:fadingEdgeLength="0dp"
        android:scrollbars="none"
        android:id="@+id/scroll">
        <LinearLayout
            android:layout_height="fill_parent"
            android:layout_width="fill_parent"
            android:orientation="vertical"
            >
            <ImageView
                android:id="@+id/image"
                android:layout_height="150dp"
                android:layout_width="fill_parent"
                android:padding="2dp"
                android:scaleType="centerCrop"
                android:src="@drawable/fruit"

                />
            <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"
                />
        </LinearLayout>
    </ScrollView>

</LinearLayout>

主类主要就是GridVIew数据绑定。简单贴下代码：

[java]
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 {

    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<String> 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;
        }
        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return texts.length;
        }

        @Override
        public Object getItem(int position) {
            // TODO Auto-generated method stub
            return null;
        }

        @Override
        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return 0;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // TODO Auto-generated method stub
            ViewHolder 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。