RxCocoa中的键盘

Question

我有一些像这样的代码：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 27
    buildToolsVersion '27.0.3'
    defaultConfig {
        applicationId "com.mixtape.tz.chat"
        minSdkVersion 15
        targetSdkVersion 27
        versionCode 22
        versionName "1.22"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"


        // Enabling multidex support.
        multiDexEnabled true

        javaCompileOptions {
            annotationProcessorOptions {
                includeCompileClasspath false
            }
        }

    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

android {
    lintOptions {
        abortOnError false
    }

    aaptOptions {
        cruncherEnabled = false

    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    androidTestImplementation('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    //compile 'io.github.rockerhieu:emojicon:1.4.0'

    //compile 'com.github.lzyzsd.randomcolor:library:1.0.0'
    implementation 'com.googlecode.libphonenumber:libphonenumber:7.3.1'
    implementation 'com.android.support:appcompat-v7:27.1.1'
    implementation 'com.squareup.okhttp3:okhttp:3.9.0'
    implementation 'com.squareup.okio:okio:1.13.0'
    implementation 'com.android.support:multidex:1.0.3'
    implementation 'com.android.support:recyclerview-v7:27.1.1'
    implementation 'com.google.firebase:firebase-messaging:17.0.0'
    implementation 'com.google.android.gms:play-services-location:15.0.1'
    implementation 'com.google.android.gms:play-services-places:15.0.1'
    implementation 'com.google.firebase:firebase-crash:16.0.1'
    implementation 'com.google.firebase:firebase-core:16.0.1'
    implementation 'com.mcxiaoke.volley:library-aar:1.0.0'
    implementation 'org.ocpsoft.prettytime:prettytime:3.2.0.Final'
    implementation 'com.android.support.constraint:constraint-layout:1.1.2'
    implementation 'com.vanniktech:emoji-one:0.4.0'
    implementation 'com.daasuu:BubbleLayout:1.1.1'
    implementation 'com.android.support:cardview-v7:27.1.1'
    implementation 'com.github.bumptech.glide:glide:4.6.1'
    implementation 'com.android.support:design:27.1.1'
    implementation 'com.android.support:support-annotations:27.1.1'
    implementation 'net.opacapp:multiline-collapsingtoolbar:1.4.0'
    implementation 'com.squareup.picasso:picasso:2.5.2'
    implementation 'com.theartofdev.edmodo:android-image-cropper:2.1.2'
    implementation 'de.hdodenhof:circleimageview:2.1.0'
    implementation 'com.google.cloud:google-cloud-translate:1.14.0'
    annotationProcessor 'com.google.dagger:dagger-compiler:2.0'
    testImplementation 'junit:junit:4.12'
}

apply plugin: 'com.google.gms.google-services'

我发现.bind（to :)操作符会在每次用户点击Return Key按钮时关闭键盘。那么如何才能让键盘不被解雇呢？ 感谢