视图类型中的方法setOnClickListener（View.OnClickListener）不适用于自变量（起点）

Question

I am trying to develop a twitter client using android. My entire code is error free for now excepting the line " signIn.setOnClickListener(this);". I've tried following every other suggestion but they don't seem to help. The error reported is "The method setOnClickListener(View.OnClickListener) in the type View is not applicable for the arguments (startingpoint)". According to suggestions it seems i should use "View" instead of "signIn". What could be the possible explanation and where do i need to correct my code?

package com.HIT.bjak;

import twitter4j.Twitter;
import twitter4j.TwitterException;
import twitter4j.TwitterFactory;
import twitter4j.auth.AccessToken;
import twitter4j.auth.RequestToken;
import android.app.Activity;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;

public class startingpoint extends Activity implements OnClickListener {

/** developer account key for this app */
public final static String TWIT_KEY = "xxx";
/** developer secret for the app */
public final static String TWIT_SECRET = "xxx";
/** app url */
public final static String TWIT_URL = "bjak-android:///";
/** Twitter instance */
private Twitter bjak_instance;
/** request token for accessing user account */
private RequestToken bjak_RequestToken;
/** shared preferences to store user details */
private SharedPreferences Prefs;

// for error logging
private String LOG_TAG = "startingpoint";

Button signIn;
String oaVerifier=null;
@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    // get the preferences for the app
    bjak_instance = (Twitter) getSharedPreferences("TweetPrefs", 0);

    // find out if the user preferences are set
    if ( Prefs.getString("user_token", null) == null) {

        // no user preferences so prompt to sign in
        setContentView(R.layout.main);
        // get a twitter instance for authentication
        bjak_instance = new TwitterFactory().getInstance();

        // pass developer key and secret
        bjak_instance.setOAuthConsumer(TWIT_KEY, TWIT_SECRET);
        // try to get request token
        try {
            // get authentication request token
            bjak_RequestToken = bjak_instance.getOAuthRequestToken(TWIT_URL);
        } catch (TwitterException te) {
            Log.e(LOG_TAG, "TE " + te.getMessage());
        }
        // setup button for click listener
        signIn = (Button)findViewById(R.id.signin);
        signIn.setOnClickListener(this);
        //attempt to retrieve access token
        try
        {
            //try to get an access token using the returned data from the verification page
            AccessToken accToken = bjak_instance.getOAuthAccessToken(bjak_RequestToken, oaVerifier);

            //add the token and secret to shared prefs for future reference
            Prefs.edit()
                .putString("user_token", accToken.getToken())
                .putString("user_secret", accToken.getTokenSecret())
                .commit();

            //display the timeline
            setupTimeline();
        }
        catch (TwitterException te)
        { Log.e(LOG_TAG, "Failed to get access token: " + te.getMessage()); }

    } else {
        // user preferences are set - get timeline
        setupTimeline();
    }
}

/**
 * Click listener handles sign in and tweet button presses
 */
public void onClick(View v) {
    // find view
    switch (v.getId()) {
    // sign in button pressed
    case R.id.signin:
        // take user to twitter authentication web page to allow app access
        // to their twitter account
        String authURL = bjak_RequestToken.getAuthenticationURL();
        startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(authURL)));
        break;
    // other listeners here

    default:
        break;
    }

}
/*
 * onNewIntent fires when user returns from Twitter authentication Web page
 */
@Override
protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    //get the retrieved data
    Uri twitURI = intent.getData();
    //make sure the url is correct
    if(twitURI!=null && twitURI.toString().startsWith(TWIT_URL))
    {
        //is verifcation - get the returned data
        oaVerifier = twitURI.getQueryParameter("oauth_verifier");

    }
}
private void setupTimeline() {
    Log.v(LOG_TAG, "setting up timeline");
    }

@Override
public void onClick(DialogInterface dialog, int which) {
    // TODO Auto-generated method stub

}

}`

Answer 1

this is because the interface your activity implements is wrong!

import android.content.DialogInterface.OnClickListener;
...
public class startingpoint extends Activity implements OnClickListener {

you should implements this interface View.OnClickListener .