android之‘com.example.android.apis.view’的代码段

1.AutoCompleteTextView

ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_dropdown_item_1line, COUNTRIES);
AutoCompleteTextView textView = (AutoCompleteTextView) findViewById(R.id.edit);
textView.setAdapter(adapter);
//this word for auto-completion by words
textView.setTokenizer(new MultiAutoCompleteTextView.CommaTokenizer());

static final String[] COUNTRIES = new String[] {
    "Afghanistan", "Albania", "Algeria", "American Samoa", "Andorra",
    "Angola", "Anguilla", "Antarctica", "Antigua and Barbuda", "Argentina",
    "Armenia", "Aruba", "Australia", "Austria", "Azerbaijan",
    "Bahrain", "Bangladesh", "Barbados", "Belarus", "Belgium",
    "Belize", "Benin", "Bermuda", "Bhutan", "Bolivia",
    "Bosnia and Herzegovina", "Botswana", "Bouvet Island", "Brazil", "British Indian Ocean Territory",
    "British Virgin Islands", "Brunei", "Bulgaria", "Burkina Faso", "Burundi",
    "Cote d'Ivoire", "Cambodia", "Cameroon", "Canada", "Cape Verde",
    "Cayman Islands", "Central African Republic", "Chad", "Chile", "China",
    "Christmas Island", "Cocos (Keeling) Islands"}

2.LinearLayout 的android:baselineAlignedChildIndex="2"属性作用。一张图片说明其作用

3.GridLayout 简化了对复杂布局的处理，包括性能提高不是一倍两倍。但是不支持SDK版本低于14的手机。不过有兼容包，不过我还没找到。

请看布局代码：

<?xml version="1.0" encoding="utf-8"?>
<!--
     Copyright (C) 2011 The Android Open Source Project

     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
     You may obtain a copy of the License at

          http://www.apache.org/licenses/LICENSE-2.0

     Unless required by applicable law or agreed to in writing, software
     distributed under the License is distributed on an "AS IS" BASIS,
     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     See the License for the specific language governing permissions and
     limitations under the License.
-->

<GridLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:alignmentMode="alignBounds"
    android:columnCount="4"
    android:columnOrderPreserved="false"
    android:useDefaultMargins="false" >

    <EditText
        android:layout_columnSpan="3"
        android:layout_gravity="fill" />

    <Button android:text="/"/>

    <Button android:text="1" />

    <Button android:text="2" />

    <Button android:text="3" />

    <Button android:text="*" />

    <Button android:text="4" />

    <Button android:text="5" />

    <Button android:text="6" />

    <Button android:text="-" />

    <Button android:text="7" />

    <Button android:text="8" />

    <Button android:text="9" />

    <Button
        android:layout_gravity="fill_vertical"
        android:layout_rowSpan="3"
        android:text="+" />

    <Button
        android:layout_columnSpan="2"
        android:layout_gravity="fill"
        android:text="0" />

    <Button android:text="00" />

    <Button
        android:layout_columnSpan="3"
        android:layout_gravity="fill_horizontal"
        android:text="=" />

</GridLayout>

效果图如下：