Android 文件选择器不从 Android Webview 调用

Question

它是一个带有 Webview 的简单 WebApp，并且有一个带有上传文件选项的注册页面。单击浏览按钮时尝试打开文件选择器但没有响应。我假设我的 gradle 文件中存在一些问题。请帮我调试一下。这是我的代码。

这是我的项目gradle

    buildscript {

        repositories {
            google()
            jcenter()
            mavenCentral()
        }
        dependencies {
            classpath 'com.android.tools.build:gradle:3.1.3'
            classpath 'com.google.gms:google-services:3.2.1'
        }
    }
    allprojects {
        repositories {
            google()
            jcenter()
        }
    }

    task clean(type: Delete) {
        delete rootProject.buildDir
    }

这是我的应用程序 gradle

android {
    compileSdkVersion 27
    defaultConfig {
        applicationId "com.androidapp.myApp"
        minSdkVersion 15
        targetSdkVersion 27
        versionCode 2
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        useLibrary 'org.apache.http.legacy'

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

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:27.1.1'
    implementation 'com.android.support:support-v4:27.1.1'
    implementation 'com.google.firebase:firebase-invites:16.0.1'
    implementation 'com.google.firebase:firebase-messaging:17.1.0'

    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'com.squareup.okhttp3:okhttp:3.8.0'

    implementation 'com.android.support:multidex:1.0.3'


}

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

Answer 1

不是gradle文件错误。您只需提供如下所示的自定义 WebChromeClient。

class MyWebChromeClient extends WebChromeClient {
    // For 3.0+ Devices (Start)
    // onActivityResult attached before constructor
    protected void openFileChooser(ValueCallback uploadMsg, String acceptType) {
        mUploadMessage = uploadMsg;
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        i.setType("image/*");
        startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE);
    }


    // For Lollipop 5.0+ Devices
    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public boolean onShowFileChooser(WebView mWebView, ValueCallback<Uri[]> filePathCallback, FileChooserParams fileChooserParams) {
        if (uploadMessage != null) {
            uploadMessage.onReceiveValue(null);
            uploadMessage = null;
        }

        uploadMessage = filePathCallback;

        Intent intent = fileChooserParams.createIntent();
        try {
            startActivityForResult(intent, REQUEST_SELECT_FILE);
        } catch (ActivityNotFoundException e) {
            uploadMessage = null;
            Toast.makeText(WebLink.this, "Cannot Open File Chooser", Toast.LENGTH_LONG).show();
            return false;
        }
        return true;
    }

    //For Android 4.1 only
    protected void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
        mUploadMessage = uploadMsg;
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.addCategory(Intent.CATEGORY_OPENABLE);
        intent.setType("image/*");
        startActivityForResult(Intent.createChooser(intent, "File Chooser"), FILECHOOSER_RESULTCODE);
    }

    protected void openFileChooser(ValueCallback<Uri> uploadMsg) {
        mUploadMessage = uploadMsg;
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        i.setType("image/*");
        startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE);
    }
}

它在你的 WebView 中如下所示

webview.setWebChromeClient(new MyWebChromeClient());

要全局声明的一些其他有用的东西/变量。

public ValueCallback<Uri[]> uploadMessage;
private ValueCallback<Uri> mUploadMessage;
public static final int REQUEST_SELECT_FILE = 100;
private final static int FILECHOOSER_RESULTCODE = 1;

确保你拥有所有的读/写权限

更新

使用下面的行提供对存储文件的访问权限。

webview.getSettings().setDomStorageEnabled(true);
webview.getSettings().setAllowContentAccess(true);
webview.getSettings().setAllowFileAccess(true);

// EDIT, add this line also
webview.getSettings().setJavaScriptEnabled(true);

更新 2

在 onActivityResult 方法中获取结果。您可以使用如下给出的结果。

@Override
public void onActivityResult(int requestCode, int resultCode, Intent intent) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        if (requestCode == REQUEST_SELECT_FILE) {
            if (uploadMessage == null)
                return;
            uploadMessage.onReceiveValue(WebChromeClient.FileChooserParams.parseResult(resultCode, intent));
            uploadMessage = null;
        }
    } else if (requestCode == FILECHOOSER_RESULTCODE) {
        if (null == mUploadMessage)
            return;
        // Use MainActivity.RESULT_OK if you're implementing WebView inside Fragment
        // Use RESULT_OK only if you're implementing WebView inside an Activity
        Uri result = intent == null || resultCode != WebLink.RESULT_OK ? null : intent.getData();
        mUploadMessage.onReceiveValue(result);
        mUploadMessage = null;
    } else
        Toast.makeText(WebLink.this, "Failed to Upload Image", Toast.LENGTH_LONG).show();
}