Android 键盘弹起和回落事件监听

转载请注明出处
http://blog.youkuaiyun.com/u014513456/article/details/54343765
Author：ruanjianjiagou@163.com
背景
在京东金融APP的登陆页面键盘弹出后整个布局上移，键盘弹起后，用户仍能看到页面全部内容，这样的用户体验要好于键盘弹起后紧贴输入框下侧，或者键盘弹起后直接连输入的区域都遮挡。

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技术点
遗憾的是系统并不提供键盘弹起的事件监听
1.键盘事件的监听
2.布局的移动

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以下为解决方案

AndroidMainfest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="open.ppdai.com.keyboardlogin">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity
            android:name=".MainActivity"
            android:windowSoftInputMode="stateAlwaysHidden|adjustResize">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

以下是关键语句

<activity
  android:name=".MainActivity"        android:windowSoftInputMode="stateAlwaysHidden|adjustResize">

Activity

package open.ppdai.com.keyboardlogin;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.Toast;

/**
 * Author ruanjianjiagou@163.com
 * 捕捉界面键盘弹起动作
 * 例如 京东金融 登陆界面 在输入框获取焦点后键盘弹出把整个布局上移
 * 键盘回落后布局也相应回落
 *
 */
public class MainActivity extends AppCompatActivity {

    private LinearLayout root_view;

    private int screenHeight = 0;
    private int keyHeight = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        initListener();
        initOtherData();
    }

    private void initView() {
        root_view = (LinearLayout) findViewById(R.id.root_view);
    }

    private void initListener() {
        root_view.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
            @Override
            public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {
                if (oldBottom != 0 && bottom != 0 && (oldBottom - bottom > keyHeight)) {
                    Toast.makeText(MainActivity.this,"键盘弹起",Toast.LENGTH_SHORT).show();
                } else if (oldBottom != 0 && bottom != 0 && (bottom - oldBottom > keyHeight)) {
                    Toast.makeText(MainActivity.this,"键盘落下",Toast.LENGTH_SHORT).show();
                }
            }
        });
    }

    private void initOtherData() {
        screenHeight = this.getWindowManager().getDefaultDisplay().getHeight();
        keyHeight = screenHeight / 3;
    }

}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/root_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center_horizontal"
    android:orientation="vertical"
    tools:context="open.ppdai.com.keyboardlogin.MainActivity">


    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="64dp"
        android:background="@mipmap/ic_launcher" />

    <EditText
        android:id="@+id/user"
        android:layout_width="match_parent"
        android:layout_height="48dp"
        android:hint="username"
        android:textColorHint="#cccccc" />

    <EditText
        android:id="@+id/pass"
        android:layout_width="match_parent"
        android:layout_height="48dp"
        android:hint="password"
        android:textColorHint="#cccccc" />

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="register!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.502" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="48dp"
        android:layout_marginTop="16dp"
        android:text="login" />
</LinearLayout>

有了监听事件了，那剩下的就是布局移动了，请看下篇

Android 键盘弹起和回落事件监听(二)之移动布局
http://blog.youkuaiyun.com/u014513456/article/details/54378781

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源码戳我下载
http://download.youkuaiyun.com/download/u014513456/9735954