可扩展列表 Android 滚动时黑色背景

发布于 2024-12-05 17:18:47 字数 2593 浏览 5 评论 0原文

我在 Android 中的 ExpandableList 视图上遇到了困难。 我正在使用 api 演示中提供的代码,但我不知道如何解决我的问题。

我的视图上有白色背景,但当我滚动列表时它会变成黑色......为什么?

我不想要这种效果...有什么办法可以改变它吗?有没有办法使用此代码自定义列表? 我正在寻找这样的东西..希望你能帮助我! 谢谢 :)

package com.example.android.apis.view;

import android.R;
import android.app.ExpandableListActivity;
import android.os.Bundle;
import android.widget.ExpandableListAdapter;
import android.widget.SimpleExpandableListAdapter;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


/**
 * Demonstrates expandable lists backed by a Simple Map-based adapter
 */
public class ExpandableList3 extends ExpandableListActivity {
    private static final String NAME = "NAME";
    private static final String IS_EVEN = "IS_EVEN";

    private ExpandableListAdapter mAdapter;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        List<Map<String, String>> groupData = new ArrayList<Map<String, String>>();
        List<List<Map<String, String>>> childData = new ArrayList<List<Map<String, String>>>();
        for (int i = 0; i < 20; i++) {
            Map<String, String> curGroupMap = new HashMap<String, String>();
            groupData.add(curGroupMap);
            curGroupMap.put(NAME, "Group " + i);
            curGroupMap.put(IS_EVEN, (i % 2 == 0) ? "This group is even" : "This group is odd");

            List<Map<String, String>> children = new ArrayList<Map<String, String>>();
            for (int j = 0; j < 15; j++) {
                Map<String, String> curChildMap = new HashMap<String, String>();
                children.add(curChildMap);
                curChildMap.put(NAME, "Child " + j);
                curChildMap.put(IS_EVEN, (j % 2 == 0) ? "This child is even" : "This child is odd");
            }
            childData.add(children);
        }

        // Set up our adapter

        mAdapter = new SimpleExpandableListAdapter(
                this,
                groupData,
                android.R.layout.simple_expandable_list_item_1,
                new String[] { NAME, IS_EVEN },
                new int[] { android.R.id.text1, android.R.id.text2 },
                childData,
                R.layout.simple_expandable_list_item_3,
                new String[] { NAME, IS_EVEN },
                new int[] { android.R.id.text1, android.R.id.text2 }
                );

        setListAdapter(mAdapter);
    }

}

I'm struggling with the ExpandableList View in Android.
I'm using the code provided in the apis demo but I don't know how to solve my problem.

I got a white background on my view but when I'm scrolling the list it turns black..why?

I don't want this effect...is there a way to change it? is there a way to customize the list using this code?
I'm looking for something like this..Hope you could help me!
Thank you :)

package com.example.android.apis.view;

import android.R;
import android.app.ExpandableListActivity;
import android.os.Bundle;
import android.widget.ExpandableListAdapter;
import android.widget.SimpleExpandableListAdapter;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


/**
 * Demonstrates expandable lists backed by a Simple Map-based adapter
 */
public class ExpandableList3 extends ExpandableListActivity {
    private static final String NAME = "NAME";
    private static final String IS_EVEN = "IS_EVEN";

    private ExpandableListAdapter mAdapter;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        List<Map<String, String>> groupData = new ArrayList<Map<String, String>>();
        List<List<Map<String, String>>> childData = new ArrayList<List<Map<String, String>>>();
        for (int i = 0; i < 20; i++) {
            Map<String, String> curGroupMap = new HashMap<String, String>();
            groupData.add(curGroupMap);
            curGroupMap.put(NAME, "Group " + i);
            curGroupMap.put(IS_EVEN, (i % 2 == 0) ? "This group is even" : "This group is odd");

            List<Map<String, String>> children = new ArrayList<Map<String, String>>();
            for (int j = 0; j < 15; j++) {
                Map<String, String> curChildMap = new HashMap<String, String>();
                children.add(curChildMap);
                curChildMap.put(NAME, "Child " + j);
                curChildMap.put(IS_EVEN, (j % 2 == 0) ? "This child is even" : "This child is odd");
            }
            childData.add(children);
        }

        // Set up our adapter

        mAdapter = new SimpleExpandableListAdapter(
                this,
                groupData,
                android.R.layout.simple_expandable_list_item_1,
                new String[] { NAME, IS_EVEN },
                new int[] { android.R.id.text1, android.R.id.text2 },
                childData,
                R.layout.simple_expandable_list_item_3,
                new String[] { NAME, IS_EVEN },
                new int[] { android.R.id.text1, android.R.id.text2 }
                );

        setListAdapter(mAdapter);
    }

}

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评论(6

挽梦忆笙歌 2024-12-12 17:18:47

添加到 xml 文件中的列表视图:

android:cacheColorHint="#00000000"

或在 Java 代码中:

getListView().setCacheColorHint(0);

Add to your listview in the xml file:

android:cacheColorHint="#00000000"

or in your Java code:

getListView().setCacheColorHint(0);

阳光的暖冬 2024-12-12 17:18:47

android:cacheColorHint="#00000000" 添加到 ListView

示例;

<ListView
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:id="@+id/list"
   android:cacheColorHint="#00000000" />

add android:cacheColorHint="#00000000" to ListView

example;

<ListView
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:id="@+id/list"
   android:cacheColorHint="#00000000" />
清秋悲枫 2024-12-12 17:18:47

在你的 xml 中写入这个,你会得到答案

android:scrollingCache="false"

Write this one in your xml you will get the answer

android:scrollingCache="false"

铜锣湾横着走 2024-12-12 17:18:47

按照此链接上的说明进行操作:

Android 开发人员资源:Listview 背景

简而言之:
...要解决此问题,您所要做的就是禁用缓存颜色提示优化(如果您使用非纯色背景),或者将提示设置为适当的纯色值。您可以从代码中执行此操作(请参阅 setCacheColorHint(int)),或者最好使用 android:cacheColorHint 属性从 XML 中执行此操作。要禁用优化,只需使用透明颜色#00000000。以下屏幕截图显示了 XML 布局文件中设置的 android:cacheColorHint="#00000000" 列表...

Follow the instructions on this link:

Android Developer Ressources: Listview Backgrounds

In short:
...To fix this issue, all you have to do is either disable the cache color hint optimization, if you use a non-solid color background, or set the hint to the appropriate solid color value. You can do this from code (see setCacheColorHint(int)) or preferably from XML, by using the android:cacheColorHint attribute. To disable the optimization, simply use the transparent color #00000000. The following screenshot shows a list with android:cacheColorHint="#00000000" set in the XML layout file ...

沐歌 2024-12-12 17:18:47

我只想指出,有一种更优雅的方式来表达#00000000,只需使用:@android/color/transparent。如果您稍后再回到该代码,就会更容易理解(是的,我知道无论如何它只是一个 ARGB 数字;-))。

I'd just like to point out that there's a more elegant way of expressing #00000000, just use: @android/color/transparent. It's easier to understand if you come back to that code some time later (Yeah, I know that it's just an ARGB number anyway ;-)).

殤城〤 2024-12-12 17:18:47

设置列表颜色:

android:cacheColorHint="#000000"

只需使用以下方法或在 Java 代码中

listView.setCacheColorHint(0);

Simply set your list color, using the methods below:

android:cacheColorHint="#000000"

or in your Java code:

listView.setCacheColorHint(0);
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