如何在Android中以编程方式使列表视图项左右对齐 [英] How to make list view items align left and right programmatically in Android

问题描述

我正在使用一个聊天应用程序，并且在聊天视图中，我必须左右显示消息.但是由于我在Android编程领域还很陌生，所以我无法实现这一目标.这就是我得到的:

I am working on a chat app and on chat view I have to show message left and right. But as I am pretty new in Android programming, I am not being able to achieve this. Here is what I am getting :

这是我的chatbubble.xml，用于显示订单项.

Here is my chatbubble.xml that is being used to show line items.

    <?xml version="1.0" encoding="utf-8"?>
        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:id="@+id/bubble_layout_parent"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">

            <LinearLayout
                android:id="@+id/bubble_layout"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@drawable/bg_msg1">

                <TextView
                    android:id="@+id/message_text"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:maxEms="12"
                    android:layout_gravity="center"
                    android:text="Hi! new message"
                    android:textColor="@android:color/primary_text_light" />
            </LinearLayout>

        </LinearLayout>

还有ChatApapter.java的getView方法

And getView method of ChatApapter.java

    @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view = layoutInflater.inflate(resource, parent, false);

            Holder holder = new Holder();
            holder.txtMsg = (TextView) view.findViewById(R.id.message_text);

            HashMap<String,String> hashMap = new HashMap<String,String>();
            hashMap = chats.get(position);

            LinearLayout layout = (LinearLayout) view.findViewById(R.id.bubble_layout);
            LinearLayout parent_layout = (LinearLayout) view.findViewById(R.id.bubble_layout_parent);

            layout.setPadding(20,20,20,20);

            LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.WRAP_CONTENT);
            params.setMargins(0,0,0,20);
            layout.setLayoutParams(params);

            if(hashMap.get("is_mine").equals("yes")) {
                layout.setBackgroundResource(R.drawable.bg_msg1);
                parent_layout.setGravity(Gravity.RIGHT);
            } else {
                layout.setBackgroundResource(R.drawable.bg_msg2);
                parent_layout.setGravity(Gravity.LEFT);
            }

            holder.txtMsg.setText(hashMap.get("message"));
            holder.txtMsg.setTextColor(Color.BLACK);

            return view;
        }

这是activity_chat_list.xml，它是与适配器一起使用的主列表视图文件.

Here is activity_chat_list.xml that is main list view file which is being used with adapter.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.mychatapp.UserChat">

    <ListView
        android:id="@+id/msgListView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/form"
        android:divider="@null"
        android:dividerHeight="0dp"
        android:paddingBottom="10dp"
        android:text="Hello World" />

    <LinearLayout
        android:id="@+id/form"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:background="#91f1f1f1"
        android:paddingBottom="2dp">

        <EditText
            android:id="@+id/messageEditText"
            android:layout_width="252dp"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_alignParentLeft="true"
            android:layout_toLeftOf="@+id/sendMessageButton"
            android:layout_weight="0.72"
            android:ems="10"
            android:maxHeight="80dp" />

        <ImageButton
            android:id="@+id/sendMessageButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_alignParentRight="true"
            android:background="@drawable/send_button"
            android:text="d" />

    </LinearLayout>


</RelativeLayout>

所以有人可以帮助我左右传达信息.预先感谢.

So can someone help me to make message left and right. Thanks in advance.

推荐答案

您应该将 layout_gravity 设置为左侧或右侧，而不是 gravity .

You should set your layout_gravity to left or right, instead of the gravity.

我要从>如何以编程方式设置layout_gravity?

I'm copying the concept from How to set layout_gravity programmatically?

示例(警告，未测试代码):

Example (warning, code is not tested):

    LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,LinearLayout.LayoutParams.WRAP_CONTENT);


    if(hashMap.get("is_mine").equals("yes")) {
        layout.setBackgroundResource(R.drawable.bg_msg1);
        params.gravity = Gravity.RIGHT;
        parent_layout.setParams(params);
    } else {
        layout.setBackgroundResource(R.drawable.bg_msg2);
        params.gravity = Gravity.LEFT;
        parent_layout.setParams(params);
        parent_layout.setGravity(Gravity.LEFT);
    }

或者，您制作两种不同的XML，并在xml本身内部分配 layout_gravity ，并为每行填充适当的布局.

Alternatively, you make 2 different XMLs and assign layout_gravity inside the xml itself, and inflate appropriate layout for each row.

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