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我用 ArrayAdapter 创建 listView。每个项目都有很多视图。这是 getView() 方法的代码：

public View getView(final int position, View convertView, ViewGroup parent) {

    ViewHolder holder;

    if (convertView == null) {
        convertView = mInflater.inflate(R.layout.dialog_list_view, null);
        holder = new ViewHolder();
        holder.date = (TextView)convertView.findViewById(R.id.date);
        holder.multi_chat = (ImageView)convertView.findViewById(R.id.multi_chat);
        holder.my_userpick = (ImageView)convertView.findViewById(R.id.my_userpic);
        holder.name = (TextView)convertView.findViewById(R.id.name);
        holder.photo1 = (ImageView)convertView.findViewById(R.id.photo1);
        holder.photo2 = (ImageView)convertView.findViewById(R.id.photo2);
        holder.photo31 = (ImageView)convertView.findViewById(R.id.photo31);
        holder.photo32 = (ImageView)convertView.findViewById(R.id.photo32);
        holder.photo33 = (ImageView)convertView.findViewById(R.id.photo33);
        holder.photo41 = (ImageView)convertView.findViewById(R.id.photo41);
        holder.photo42 = (ImageView)convertView.findViewById(R.id.photo42);
        holder.photo43 = (ImageView)convertView.findViewById(R.id.photo43);
        holder.photo44 = (ImageView)convertView.findViewById(R.id.photo44);

        holder.text = (TextView)convertView.findViewById(R.id.text);
        holder.userpic = (ImageView)convertView.findViewById(R.id.userpic);
        holder.userpick2 = convertView.findViewById(R.id.userpick2);
        holder.userpick3 = convertView.findViewById(R.id.userpick3);
        holder.userpick4 = convertView.findViewById(R.id.userpick4);
        holder.wrapper = (RelativeLayout)convertView.findViewById(R.id.wrapper);
        convertView.setTag(holder);
    } else {
        holder = (ViewHolder) convertView.getTag();
    }

    if (dialogs != null) {
        if (position == (this.getCount() - 1)) {
            if (dialogs != null) {
                if (dates.size() > 1) {
                    dialogs.getDialogs(dates.size()+20);
                }
            }
        }
    }

    if (dates.get(position).getChatId() != 0) {
        holder.name.setText(dates.get(position).getTitle());
        holder.multi_chat.setVisibility(View.VISIBLE);
    } else {
        holder.name.setText(dates.get(position).getUidDates());
        holder.multi_chat.setVisibility(View.GONE);
    }

    if (dates.get(position).getReadState() == 0) {
        holder.wrapper.setBackgroundColor(getResources().getColor(R.color.conversation_list_no_read));
    } else {
        holder.wrapper.setBackgroundColor(android.R.color.white);
    }

    holder.text.setText(dates.get(position).getBody());

    int date = dates.get(position).getDate();
    java.util.Date time = new java.util.Date((long) date * 1000);

    if ((time.getDate() == current_date.getDate()) && (time.getMonth() == current_date.getMonth()) && (time.getYear() == current_date.getYear())) {
        holder.date.setText(time.getHours() + ":" + time.getMinutes());
    } else if ((time.getDate() == (current_date.getDate() - 1)) && (time.getMonth() == current_date.getMonth()) && (time.getYear() == current_date.getYear())) {
        holder.date.setText("вчера");
    } else {
        holder.date.setText(time.getDate() + "." + time.getMonth() + "." + (time.getYear()+1900));
    }

    if(!dates.get(position).getPhotoInText().equals("")) {
        loaderWithoutCut.displayImage(dates.get(position).getPhotoInText(), holder.my_userpick, false);
        holder.my_userpick.setVisibility(View.VISIBLE);
        holder.text.setBackgroundDrawable(getResources().getDrawable(R.drawable.dialog_rect_bg));
        holder.text.setPadding(10, 0, 10, 0);
        holder.text.setGravity(Gravity.CENTER_VERTICAL);
        holder.text.setSingleLine(true);
        holder.text.setEllipsize(TextUtils.TruncateAt.END);
    } else {
        holder.my_userpick.setVisibility(View.GONE);
        holder.text.setBackgroundColor(getResources().getColor(android.R.color.transparent));
        holder.text.setPadding(0, 0, 0, 0);
        holder.text.setSingleLine(false);
        holder.text.setGravity(Gravity.TOP);
    }


    ArrayList photos = dates.get(position).getUidPhotos();

    if (dates.get(position).getChatId() == 0) {
        if (photos.size() == 1) {
            loaderWithoutCut.displayImage((String) photos.get(0), holder.userpic, false);

            holder.userpick2.setVisibility(View.GONE);
            holder.userpick3.setVisibility(View.GONE);
            holder.userpick4.setVisibility(View.GONE);
            holder.userpic.setVisibility(View.VISIBLE);

        }
    } else {
        if ((photos.size() < 3) && (photos.size()>0)) {

            if (photos.size() == 1) {
                holder.photo1.setVisibility(View.GONE);
                loaderWithCut.displayImage((String) photos.get(0), holder.photo2, true);
            } else {
                holder.photo1.setVisibility(View.VISIBLE);
                loaderWithCut.displayImage((String) photos.get(1), holder.photo2, true);
                if (!((String) photos.get(1)).equals((String) photos.get(0))) {
                    loaderWithCut.displayImage((String) photos.get(0), holder.photo1, true);
                } else {
                    holder.photo1.setVisibility(View.GONE);
                }
            }

            holder.userpic.setVisibility(View.GONE);
            holder.userpick2.setVisibility(View.VISIBLE);
            holder.userpick3.setVisibility(View.GONE);
            holder.userpick4.setVisibility(View.GONE);

        }

        if (photos.size() == 3) {
            loaderWithCut.displayImage((String) photos.get(0), holder.photo31, true);

            loaderWithoutCut.displayImage((String) photos.get(1), holder.photo32, false);
            loaderWithoutCut.displayImage((String) photos.get(2), (ImageView) holder.photo33, false);


            holder.userpic.setVisibility(View.GONE);
            holder.userpick2.setVisibility(View.GONE);
            holder.userpick3.setVisibility(View.VISIBLE);
            holder.userpick4.setVisibility(View.GONE);

        }

        if (photos.size() >= 4) {
            loaderWithoutCut.displayImage((String) photos.get(0), holder.photo41, false);
            loaderWithoutCut.displayImage((String) photos.get(1), holder.photo42, false);
            loaderWithoutCut.displayImage((String) photos.get(2), holder.photo43, false);
            loaderWithoutCut.displayImage((String) photos.get(3), holder.photo44, false);

            holder.userpic.setVisibility(View.GONE);
            holder.userpick2.setVisibility(View.GONE);
            holder.userpick3.setVisibility(View.GONE);
            holder.userpick4.setVisibility(View.VISIBLE);

        }

    }

    if (photos.size() == 0) {

        holder.userpick2.setVisibility(View.GONE);
        holder.userpick3.setVisibility(View.GONE);
        holder.userpick4.setVisibility(View.GONE);

    }


    final ViewHolder holder2 = holder;
    convertView.setOnFocusChangeListener(new View.OnFocusChangeListener() {

        @Override
        public void onFocusChange(View v, boolean hasFocus) {

            TextView text = holder2.text;
            TextView date = holder2.date;
            TextView name = holder2.name;

            if (hasFocus) {
                text.setTextColor(getResources().getColor(android.R.color.white));
                date.setTextColor(getResources().getColor(android.R.color.white));
                name.setTextColor(getResources().getColor(android.R.color.white));
            } else {
                text.setTextColor(getResources().getColor(R.color.dialog_text));
                date.setTextColor(getResources().getColor(R.color.dialog_date));
                name.setTextColor(getResources().getColor(R.color.friends_text_color));
            }
        }
    });

    return convertView;
}

问题是 - 列表视图滚动工作非常缓慢。我该如何解决这个问题？布局代码：

<?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="wrap_content"
              android:gravity="center_vertical" android:background="@drawable/list_drawable_settings">
    <RelativeLayout
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:gravity="center_vertical" android:id="@+id/wrapper">
        <LinearLayout android:layout_width="52dip" android:id="@+id/images" android:layout_margin="6dip"
                      android:layout_height="58dip">
            <com.vk.messenger.views.RoundedConersImageView android:id="@+id/userpic"
                       android:layout_height="wrap_content" android:layout_width="wrap_content"
                       />
            <LinearLayout android:layout_width="wrap_content" android:id="@+id/userpick2"
                          android:layout_height="wrap_content">
                <LinearLayout android:layout_width="26dip"
                              android:layout_height="58dip">
                    <com.vk.messenger.views.ScalledImageView android:scaleType="fitCenter"
                               android:cropToPadding="true" android:layout_width="26dip"
                               android:layout_height="58dip"
                               android:id="@+id/photo1"/>
                </LinearLayout>
                <LinearLayout android:layout_width="26dip"
                              android:layout_height="58dip">
                    <com.vk.messenger.views.ScalledImageView android:layout_width="26dip"
                                                             android:layout_height="58dip" android:scaleType="fitCenter"
                               android:cropToPadding="true"
                               android:id="@+id/photo2"/>
                </LinearLayout>
            </LinearLayout>
            <LinearLayout android:layout_width="wrap_content" android:id="@+id/userpick3"
                          android:layout_height="wrap_content">
                <ImageView android:layout_width="26dip" android:layout_height="58dip" android:id="@+id/photo31"
                        ></ImageView>
                <LinearLayout android:layout_width="26dip" android:id="@+id/userpick3"
                              android:layout_height="58dip"
                              android:orientation="vertical">
                    <ImageView android:layout_width="26dip"
                               android:scaleType="fitCenter" android:cropToPadding="true"
                               android:layout_height="26dip" android:id="@+id/photo32"
                            ></ImageView>
                    <ImageView android:layout_width="26dip"
                               android:scaleType="fitCenter" android:cropToPadding="true"
                               android:layout_height="29dip" android:id="@+id/photo33"
                            ></ImageView>
                </LinearLayout>
            </LinearLayout>
            <LinearLayout android:layout_width="52dip" android:id="@+id/userpick4"
                          android:layout_height="58dip" android:orientation="horizontal">
                <LinearLayout android:layout_width="26dip"
                              android:layout_height="58dip"

                              android:orientation="vertical">
                    <ImageView android:layout_width="26dip"
                               android:layout_height="29dip" android:id="@+id/photo41"
                            ></ImageView>
                    <ImageView android:layout_width="26dip"
                               android:layout_height="29dip" android:id="@+id/photo42"
                            ></ImageView>
                </LinearLayout>
                <LinearLayout android:layout_width="26dip"
                              android:layout_height="58dip"
                              android:orientation="vertical">
                    <ImageView android:layout_width="26dip"
                               android:layout_height="29dip" android:id="@+id/photo43"
                            ></ImageView>
                    <ImageView android:layout_width="26dip"
                               android:layout_height="29dip" android:id="@+id/photo44"
                            ></ImageView>
                </LinearLayout>
            </LinearLayout>
        </LinearLayout>

        <RelativeLayout android:layout_width="fill_parent" android:layout_height="wrap_content"
                      android:layout_centerVertical="true"
                      android:layout_toRightOf="@id/images" android:layout_marginLeft="4dip">
            <LinearLayout android:layout_width="fill_parent" android:orientation="vertical" android:id="@+id/left" android:layout_height="wrap_content">
            <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content">
                <ImageView android:id="@+id/multi_chat" android:visibility="invisible" android:paddingTop="3dip" android:paddingRight="2dip"
                           android:src="@drawable/multi_chat"
                           android:layout_height="wrap_content" android:layout_width="wrap_content"
                        />
                <com.vk.messenger.views.TextViewMyriadPro android:id="@+id/name" android:text="" android:singleLine="true" android:ellipsize="end"
                          android:layout_centerVertical="true"
                          android:textColor="@color/friends_text_color" android:textSize="16dip" android:textStyle="bold"
                          android:layout_height="wrap_content" android:layout_width="fill_parent" android:layout_weight="1"/>
                <com.vk.messenger.views.TextViewHelvetica android:id="@+id/date" android:layout_marginLeft="6dip" android:gravity="right" android:layout_marginRight="6dip" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textColor="@color/dialog_date"
                                                          android:textSize="13dip"/>
            </LinearLayout>
            <LinearLayout android:layout_height="wrap_content"
                          android:layout_width="fill_parent" android:layout_weight="1" android:layout_marginTop="2dip">
                <com.vk.messenger.views.RoundedConersImageView android:id="@+id/my_userpic" android:visibility="gone" android:paddingRight="2dip"
                           android:layout_height="30dip" android:layout_width="30dip"/>
                <com.vk.messenger.views.TextViewHelvetica android:id="@+id/text" android:text="текст" android:layout_below="@id/name"
                          android:layout_centerVertical="true" android:layout_marginLeft="3dip" android:layout_marginRight="6dip"
                          android:textColor="@color/dialog_text" android:textSize="13dip"
                          android:layout_height="fill_parent"
                          android:layout_width="fill_parent" />
            </LinearLayout>
            </LinearLayout>
        </RelativeLayout>

    </RelativeLayout>
</LinearLayout>
4

2 回答 2

0

我认为您只是在 getview 中做的太多，每次您尝试滚动时都必须为每个可见的列表项运行所有代码，发生的事情太多了。

还有那些 loadWithCut/loadWitoutCut 是什么？你从哪里加载图像？你在getview中处理图像吗？

如果可能的话，我会首先尝试将任何对象创建移出 getView，然后在各种方法中进行一些日志记录，以查看发生缓慢的确切位置。

于 2012-07-07T14:24:07.497 回答
0

我会考虑摆脱你的嵌套LinearLayouts。您应该使用RelativeLayout, 而不是嵌套LinearLayouts; 特别是如果你正在嵌套LinearLayouts。由于您使用了如此多的图像，您可能需要考虑重新调整布局。这是一篇讨论如何以及为什么的文章：

http://android-developers.blogspot.com/2009/02/android-layout-tricks-1.html

你也可以考虑打破你的getView方法，那里有很多事情要做。getView必须为每个调用执行大部分代码，这可能是导致问题的原因。您应该考虑创建另一个类。

于 2012-07-07T15:03:34.330 回答