Android自定义输入法软键盘

1 功能描述

• 触屏设备主界面中有一个文本编辑框，底部区域固定显示一个数字键盘，键盘中除数字键外，还带有*和＃键功能；
• 提供一个自定义的数字输入法，生成apk安装包文件，嵌入到img镜像文件中去。

2 设计实现

1. 创建类名为SimpleIME，继承父类InputMethodService，实现KeyboardView.OnKeyboardActionListener接口。
2. 编写键盘对象加载的.xml文件。
3. 重写onCreateInputView()方法，初始化键盘视图和创建键盘对象，使用键盘视图对象设置键盘的监听。
4. 重写onKey、onPress、onRelease、onText、swipeDown、swipeLeft、swipeRight和swipeUp等方法，在onKey方法中可处理对键盘的操作，在这个方法里通过传入的primaryCode进行相应的操作。其他方法没有具体的实现。
5. 配置清单文件的声明service，还向系统申请了IME的BIND_INPUT_METHOD权限，并且给IME添加了一个名称为android.view.InputMethod的过滤器，用来存放意图的属性。

3 贴出代码

1. SimpleIME.java

import android.inputmethodservice.InputMethodService;
import android.inputmethodservice.Keyboard;
import android.inputmethodservice.KeyboardView;
import android.media.AudioManager;
import android.view.KeyEvent;
import android.view.View;
import android.view.inputmethod.InputConnection;

/**
 * @description: 自定义输入法
 * @version: v1.0
 * @author: yeyl
 * @date: 2018/6/26 14:57
 * @history:
 */
public class SimpleIME extends InputMethodService
        implements KeyboardView.OnKeyboardActionListener {
    
    

    private KeyboardView mKeyboardView;
    private Keyboard mKeyboard;
    /**
     * 大小写转换的flag
     */
    private boolean mCaps = false;

    @Override
    public View onCreateInputView() {
    
    
        mKeyboardView = (KeyboardView) getLayoutInflater().inflate(R.layout.layout_keyboard, null);
        mKeyboard = new Keyboard(this, R.xml.keyboard_number);
        mKeyboardView.setKeyboard(mKeyboard);
        mKeyboardView.setOnKeyboardActionListener(this);
        return mKeyboardView;
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
    
    
        return super.onKeyDown(keyCode, event);
    }

    @Override
    public void onKey(int primaryCode, int[] keyCodes) {
    
    
        InputConnection ic = getCurrentInputConnection();
        playClick(primaryCode);
        switch (primaryCode) {
    
    
            case Keyboard.KEYCODE_DELETE:
                // 回退
                ic.deleteSurroundingText(1, 0);
                break;
            case Keyboard.KEYCODE_SHIFT:
                // 大小写切换
                mCaps = !mCaps;
                mKeyboard.setShifted(mCaps);
                mKeyboardView.invalidateAllKeys();
                break;
            case Keyboard.KEYCODE_DONE:
                // 完成
                ic.sendKeyEvent(new KeyEvent(KeyEvent.ACTION_UP, KeyEvent.KEYCODE_ENTER));
                break;
            case Keyboard.KEYCODE_CANCEL:
                // 取消
                ic.sendKeyEvent(new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_BACK));
                ic.sendKeyEvent(new KeyEvent(KeyEvent.ACTION_UP, KeyEvent.KEYCODE_BACK));
                break;
            default:
                char code = (char) primaryCode;
                if (Character.isLetter(code) && mCaps) {
    
    
                    code = Character.toUpperCase(code);
                }
                ic.commitText(String.valueOf(code), 1);
        }
    }

    /**
     * 播放按键音
     *
     * @param keyCode 键码
     */
    private void playClick(int keyCode) {
    
    
        AudioManager am = (AudioManager) getSystemService(AUDIO_SERVICE);
        switch (keyCode) {
    
    
            case 32:
                am.playSoundEffect(AudioManager.FX_KEYPRESS_SPACEBAR);
                break;
            case Keyboard.KEYCODE_DONE:
            case 10:
                am.playSoundEffect(AudioManager.FX_KEYPRESS_RETURN);
                break;
            case Keyboard.KEYCODE_DELETE:
                am.playSoundEffect(AudioManager.FX_KEYPRESS_DELETE);
                break;
            default:
                am.playSoundEffect(AudioManager.FX_KEYPRESS_STANDARD);
        }
    }

    @Override
    public void onPress(int primaryCode) {
    
    
    }

    @Override
    public void onRelease(int primaryCode) {
    
    
    }

    @Override
    public void onText(CharSequence text) {
    
    
    }

    @Override
    public void swipeDown() {
    
    
    }

    @Override
    public void swipeLeft() {
    
    
    }

    @Override
    public void swipeRight() {
    
    
    }

    @Override
    public void swipeUp() {
    
    
    }
}

2. layout_keyboard.xml

<?xml version="1.0" encoding="UTF-8"?>
<android.inputmethodservice.KeyboardView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/keyboard"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:keyPreviewLayout="@layout/layout_preview" />

3. layout_preview.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#FFFF00"
    android:gravity="center"
    android:textSize="30sp"
    android:textStyle="bold" />

4. keyboard_number.xml

<?xml version="1.0" encoding="utf-8"?>
<Keyboard xmlns:android="http://schemas.android.com/apk/res/android"
    android:horizontalGap="0px"
    android:keyWidth="33.3%p"
    android:keyHeight="9%p"
    android:verticalGap="0px">
    <Row>
        <Key
            android:codes="49"
            android:keyEdgeFlags="left"
            android:keyLabel="1" />
        <Key
            android:codes="50"
            android:keyLabel="2" />
        <Key
            android:codes="51"
            android:keyEdgeFlags="right"
            android:keyLabel="3" />
    </Row>
    <Row>
        <Key
            android:codes="52"
            android:keyEdgeFlags="left"
            android:keyLabel="4" />
        <Key
            android:codes="53"
            android:keyLabel="5" />
        <Key
            android:codes="54"
            android:keyEdgeFlags="right"
            android:keyLabel="6" />
    </Row>
    <Row>
        <Key
            android:codes="55"
            android:keyEdgeFlags="left"
            android:keyLabel="7" />
        <Key
            android:codes="56"
            android:keyLabel="8" />
        <Key
            android:codes="57"
            android:keyEdgeFlags="right"
            android:keyLabel="9" />
    </Row>
    <Row android:rowEdgeFlags="bottom">
        <Key
            android:codes="-3"
            android:keyEdgeFlags="left"
            android:keyLabel="*" />
        <Key
            android:codes="48"
            android:keyLabel="0" />
        <Key
            android:codes="-4"
            android:isRepeatable="true"
            android:keyEdgeFlags="right"
            android:keyLabel="完成" />
    </Row>
</Keyboard>

5. AndroidManifest.xml

        <service
            android:name=".SimpleIME"
            android:label="@string/simple_ime"
            android:permission="android.permission.BIND_INPUT_METHOD">
            <meta-data
                android:name="android.view.im"
                android:resource="@xml/method" />
            <intent-filter>
                <action android:name="android.view.InputMethod" />
            </intent-filter>
        </service>

6. method.xml

<?xml version="1.0" encoding="utf-8"?>
<input-method xmlns:android="http://schemas.android.com/apk/res/android">
    <subtype
        android:imeSubtypeLocale="en_US"
        android:imeSubtypeMode="keyboard"
        android:label="@string/subtype_en_US" />
</input-method>

4 Demo截图