您好!以下是一个示例代码,演示了如何在Android WebView中下载图片和视频,并在页面上注入一个按钮。
首先,在您的项目中添加以下权限到AndroidManifest.xml文件中:
然后,在您的Activity或Fragment中,使用以下代码来设置WebView并注入按钮:
import android.Manifest;
import android.app.DownloadManager;
import android.content.Context;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.webkit.JavascriptInterface;
import android.webkit.URLUtil;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;
public class WebViewActivity extends AppCompatActivity {
private WebView webView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_web_view);
webView = findViewById(R.id.webview);
setupWebView();
loadWebPage();
}
private void setupWebView() {
WebSettings webSettings = webView.getSettings();
webSettings.setJavaScriptEnabled(true);
webView.setWebViewClient(new WebViewClient());
webView.setWebChromeClient(new WebChromeClient());
webView.addJavascriptInterface(new JavascriptInterface(this), "Android");
}
private void loadWebPage() {
webView.loadUrl("https://example.com");
}
private class JavascriptInterface {
private Context context;
JavascriptInterface(Context context) {
this.context = context;
}
@JavascriptInterface
public void downloadImage(String imageUrl) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) ==
PackageManager.PERMISSION_DENIED) {
requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
return;
}
}
DownloadManager.Request request = new DownloadManager.Request(Uri.parse(imageUrl));
request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS,
URLUtil.guessFileName(imageUrl, null, null));
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
DownloadManager downloadManager = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);
downloadManager.enqueue(request);
Toast.makeText(context, "Image downloading...", Toast.LENGTH_SHORT).show();
}
@JavascriptInterface
public void downloadVideo(String videoUrl) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) ==
PackageManager.PERMISSION_DENIED) {
requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
return;
}
}
DownloadManager.Request request = new DownloadManager.Request(Uri.parse(videoUrl));
request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS,
URLUtil.guessFileName(videoUrl, null, null));
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
DownloadManager downloadManager = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);
downloadManager.enqueue(request);
Toast.makeText(context, "Video downloading...", Toast.LENGTH_SHORT).show();
}
}
}
在上述代码中,我们首先设置了WebView的相关设置,如启用JavaScript和设置WebViewClient和WebChromeClient。然后,我们加载了一个网页。
在JavascriptInterface类中,我们定义了两个方法:downloadImage
和downloadVideo
。这些方法使用了DownloadManager来下载图片和视频,并使用Toast显示下载进度。
最后,在您的HTML页面中,您可以使用以下代码来注入按钮并调用下载方法:
请注意,您可能需要根据您的需求进行调整和修改代码。此外,如果您下载的内容需要动态权限,您还需要处理权限请求和回调。
希望以上代码对您有所帮助!如果您还有任何问题,请随时提问。