绕过错误 'can not resolve symbol'

Question

how to get around this issue?

我想在使用 onclick 单击 imageview 时显示 toast 听众.

主要activity.java:

public class LoginActivity extends AppCompatActivity implements LoaderCallbacks<Cursor> {

    /**
     * Id to identity READ_CONTACTS permission request.
     */
    private static final int REQUEST_READ_CONTACTS = 0;

    /**
     * A dummy authentication store containing known user names and passwords.
     * TODO: remove after connecting to a real authentication system.
     */
    private static final String[] DUMMY_CREDENTIALS = new String[]{
            "foo@example.com:hello", "bar@example.com:world"
    };
    /**
     * Keep track of the login task to ensure we can cancel it if requested.
     */
    private UserLoginTask mAuthTask = null;
    ObjectAnimator objectAnimator=new ObjectAnimator();

    // UI references.
    public AutoCompleteTextView mEmailView;
    public EditText mPasswordView;
    private View mProgressView;
    private View mLoginFormView;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        FacebookSdk.sdkInitialize(this.getApplicationContext());
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        // Set up the login form.
        mEmailView = (AutoCompleteTextView) findViewById(R.id.email);
        populateAutoComplete();
        ImageView mImageView= (ImageView) findViewById(R.id.imageView);

        mPasswordView = (EditText) findViewById(R.id.password);
        mPasswordView.setOnEditorActionListener(new TextView.OnEditorActionListener() {
            @Override
            public boolean onEditorAction(TextView textView, int id, KeyEvent keyEvent) {
                if (id == R.id.login || id == EditorInfo.IME_NULL) {
                    attemptLogin();
                    return true;
                }
                return false;
            }
        });

        Button mEmailSignInButton = (Button) findViewById(R.id.email_sign_in_button);
        mEmailSignInButton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View view) {
                attemptLogin();
            }
        });

        mLoginFormView = findViewById(R.id.login_form);
        mProgressView = findViewById(R.id.login_progress);

       Profile profile = Profile.getCurrentProfile().getCurrentProfile();
        if (profile != null) {
            // user has logged in

        } else {
            // user has not logged in

        }
       // SpellCheckerService.Session;//.openActiveSession(this, true, new SpellCheckerService.Session.StatusCallback() {
            // callback when session changes state
         //   @Override
         //   public void call(SpellCheckerService.Session session, SessionState state, Exception exception) {
          //  }
      //  });


        mImageView.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View view) {
                Toast.makeText(this,"done",Toast.LENGTH_SHORT).show();
            }

        });

    }

错误在这里：

mImageView.setOnClickListener(new View.OnClickListener() {

@Override public void onClick(View view) { Toast.makeText(this,"done",Toast.LENGTH_SHORT).show(); }

});

无法解析方法'maketext(anonymous ....)'

Answer 1

使用 LoginActivity.this 而不是 this 作为 makeText

的第一个参数

 mImageView.setOnClickListener(new View.OnClickListener() {

    @Override public void onClick(View view) {
           Toast.makeText(LoginActivity.this,"done",Toast.LENGTH_SHORT).show(); }
    });

希望对您有所帮助！

Answer 2

您需要使用 Activity context 而不是 "this" 例如：

 Toast.makeText(MainActivity.this, "Your message", Toast.LENGTH_LONG).show();

您当前正在调用按钮的上下文。

Answer 3

Change 
Toast.makeText(this,"done",Toast.LENGTH_SHORT).show();
to
Toast.makeText(getApplicationContext(),"done",Toast.LENGTH_SHORT).show();
or 
Toast.makeText(LoginActivity.this,"done",Toast.LENGTH_SHORT).show();

Answer 4

尝试使用

 Toast.makeText(LoginActivity.this, "Done", Toast.LENGTH_LONG).show();