Question

我的问题是为什么我不能在以下代码中使用getActivity方法。我尝试使用webView上传图片。这是我的第一个Android应用程序。我想为我的分类osclass网站创建一个应用程序。

当我构建应用程序时，我收到以下消息：

错误：找不到符号方法getActivity（）。

请更改我的代码，然后粘贴Answer或写下我应该放置代码（或更改）的位置。

package org.satlyk.org.myapplication;

import android.content.ActivityNotFoundException;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Build;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.webkit.ValueCallback;
import android.webkit.WebChromeClient;
import android.webkit.WebResourceRequest;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.FrameLayout;
import android.widget.ProgressBar;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private String WebAddress = "https://satlyk.org";
    private WebView webView;
    private ProgressBar progressBar;
    private FrameLayout frameLayout;
    private ValueCallback<Uri> mUploadMessage;
    public ValueCallback<Uri[]> uploadMessage;
    public static final int REQUEST_SELECT_FILE = 100;
    private final static int FILECHOOSER_RESULTCODE = 1;

    @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 != MainActivity.RESULT_OK ? null : intent.getData();
            mUploadMessage.onReceiveValue(result);
            mUploadMessage = null;
        }
        else
            Toast.makeText(getActivity().getApplicationContext(), "Failed to Upload Image", Toast.LENGTH_LONG).show();
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);
        frameLayout = (FrameLayout) findViewById(R.id.frameLayout);
        progressBar = (ProgressBar) findViewById(R.id.progressBar);
        progressBar.setMax(100);
        webView = findViewById(R.id.webView);
        WebSettings mWebSettings = webView.getSettings();
        mWebSettings.setJavaScriptEnabled(true);
        mWebSettings.setSupportZoom(false);
        mWebSettings.setAllowFileAccess(true);
        mWebSettings.setAllowFileAccess(true);
        mWebSettings.setAllowContentAccess(true);
        webView.getSettings().setUserAgentString("satlyk_app");
        webView.setWebViewClient(new HelpCliet());

        webView.setWebChromeClient(new 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 Browser"), FILECHOOSER_RESULTCODE);
            }

            // For Lollipop 5.0+ Devices
            public boolean onShowFileChooser(WebView mWebView, ValueCallback<Uri[]> filePathCallback, WebChromeClient.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(getActivity().getApplicationContext(), "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 Browser"), 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);
            }


                public void onProgressChanged (WebView view, int progress)
            {
                frameLayout.setVisibility(View.VISIBLE);
                progressBar.setProgress(progress);
                setTitle("Ýüklenýär...");
                if (progress == 100) {
                    frameLayout.setVisibility(View.GONE);
                    setTitle(view.getTitle());
                }
                super.onProgressChanged(view, progress);

            }

         });
        webView.getSettings() .setJavaScriptEnabled(true);
        webView.setVerticalScrollBarEnabled(false);
        webView.loadUrl(WebAddress);
        progressBar.setProgress(0);
    }

    private class HelpClient extends WebViewClient {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
           view.loadUrl(url);
           frameLayout.setVisibility(view.VISIBLE);
           return true;

        }
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            if (webView.canGoBack()) {
                webView.goBack();
                return true;
            }
        }
        return super.onKeyDown(keyCode, event);
    }
}

Answer 1

由于您已经参加了此活动，因此您不需要getActivity()。你应该能够做getApplicationContext()

Toast.makeText(getApplicationContext(), "Cannot Open File Chooser", Toast.LENGTH_LONG).show();

为什么我不能使用getActivity（）

1 个答案: