android.hardware.camera.autofocus

Android的Camera类提供了自动对焦功能。您可以使用Camera.Parameters类中的setAutoFocusMode()方法来设置自动对焦模式。以下是一个示例代码：

// 获取相机实例
Camera camera = Camera.open();

// 获取相机参数
Camera.Parameters params = camera.getParameters();

// 设置自动对焦模式
params.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);

// 应用参数
camera.setParameters(params);

// 开始预览
camera.startPreview();

在上述代码中，我们首先获取相机实例，并获取相机参数。然后，我们使用setAutoFocusMode()方法将对焦模式设置为自动对焦模式。最后，我们应用参数并开始预览。

请注意，上述代码是基于旧版的Camera类。从Android 5.0开始，Google引入了Camera2 API，提供了更强大和灵活的相机控制功能。您可以使用Camera2 API来实现自动对焦功能，但代码会更加复杂。

相关问题

找不到android.hardware:camera:2.0

如果你在使用 Android Studio 中进行开发，可以尝试在 `build.gradle` 文件中添加以下依赖项：

dependencies {
    implementation 'com.android.support:support-v4:28.0.0'
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support:design:28.0.0'
    implementation 'com.android.support:recyclerview-v7:28.0.0'
    implementation 'com.android.support:cardview-v7:28.0.0'
    implementation 'com.android.support:palette-v7:28.0.0'
    implementation 'com.android.support:support-vector-drawable:28.0.0'
    implementation 'com.android.support:animated-vector-drawable:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    implementation 'com.android.support:support-annotations:28.0.0'
    implementation 'com.android.support:support-compat:28.0.0'
    implementation 'com.android.support:support-core-ui:28.0.0'
    implementation 'com.android.support:support-core-utils:28.0.0'
    implementation 'com.android.support:support-fragment:28.0.0'
    
    implementation 'com.android.support:multidex:1.0.3'
    
    implementation 'com.google.android.gms:play-services-ads:17.2.1'
    
    implementation 'com.squareup.picasso:picasso:2.71828'
    
    implementation 'com.jakewharton:butterknife:10.1.0'
    annotationProcessor 'com.jakewharton:butterknife-compiler:10.1.0'
    
    implementation 'com.github.bumptech.glide:glide:4.8.0'
    annotationProcessor 'com.github.bumptech.glide:compiler:4.8.0'
    
    implementation 'com.squareup.retrofit2:retrofit:2.5.0'
    implementation 'com.squareup.retrofit2:converter-gson:2.5.0'
    implementation 'com.squareup.okhttp3:logging-interceptor:3.9.1'
    
    implementation 'com.google.code.gson:gson:2.8.5'
    
    implementation 'com.afollestad.material-dialogs:core:0.9.6.0'
    
    implementation 'com.github.siyamed:android-shape-imageview:0.9.+@aar'
    
    implementation 'com.squareup.okhttp3:okhttp:3.12.0'
    
    implementation 'com.github.chrisbanes:PhotoView:2.1.3'
    
    implementation 'com.google.android:flexbox:1.0.0'
    
    implementation 'com.android.support:mediarouter-v7:28.0.0'

    implementation 'com.android.support:preference-v7:28.0.0'
    
    implementation 'com.android.support:exifinterface:28.0.0'
    
    implementation 'com.google.android.gms:play-services-maps:16.0.0'
    
    implementation 'com.google.android.gms:play-services-auth:16.0.1'
    
    implementation 'com.google.android.gms:play-services-location:16.0.0'
    
    implementation 'com.google.android.gms:play-services-places:16.0.0'
    
    implementation 'com.google.android.gms:play-services-gcm:16.0.0'
    
    implementation 'com.google.android.gms:play-services-analytics:16.0.7'
    
    implementation 'com.google.android.gms:play-services-ads-identifier:16.0.0'
    
    implementation 'com.google.firebase:firebase-core:16.0.8'
    
    implementation 'com.google.firebase:firebase-ads:17.2.1'
    
    implementation 'com.firebaseui:firebase-ui-auth:4.1.0'
    
    implementation 'com.firebaseui:firebase-ui-database:4.1.0'
    
    implementation 'com.firebaseui:firebase-ui-storage:4.1.0'
    
    implementation 'com.firebaseui:firebase-ui-firestore:4.1.0'
    
    implementation 'com.firebaseui:firebase-ui:4.1.0'
    
    implementation 'com.crashlytics.sdk.android:crashlytics:2.9.9'
    
    implementation 'com.google.android.gms:play-services-vision:17.0.2'
}

然后，再检查你的 AndroidManifest.xml 文件是否已经声明了相机权限：

<uses-feature android:name="android.hardware.camera" android:required="true" />
<uses-feature android:name="android.hardware.camera.autofocus" />
<uses-permission android:name="android.permission.CAMERA" />

如果还是找不到 `android.hardware:camera:2.0`，可以尝试在 SDK Manager 中更新你的 Android SDK。