Question

我是Android应用程序编程的新手。我正在建立一个具有Listview的Android应用程序联系人列表。此行发生错误 outputText.setText(output); username.java编码在这里`

package com.letmedrive;
import com.letmedrive.util.SystemUiHider;
import android.annotation.TargetApi;
import android.app.Activity;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.view.MotionEvent;
import android.view.View;
import android.content.ContentResolver;
import android.database.Cursor;
import android.net.Uri;
import android.provider.ContactsContract;
import android.widget.ListView;
/**
* An example full-screen activity that shows and hides the system UI (i.e.
* status bar and navigation/system bar) with user interaction.
*
* @see SystemUiHider
*/





public class Username extends Activity {
public ListView outputText;

/**
 * Whether or not the system UI should be auto-hidden after
 * {@link #AUTO_HIDE_DELAY_MILLIS} milliseconds.
 */
private static final boolean AUTO_HIDE = true;

/**
 * If {@link #AUTO_HIDE} is set, the number of milliseconds to wait after
 * user interaction before hiding the system UI.
 */
private static final int AUTO_HIDE_DELAY_MILLIS = 3000;

/**
 * If set, will toggle the system UI visibility upon interaction. Otherwise,
 * will show the system UI visibility upon interaction.
 */
private static final boolean TOGGLE_ON_CLICK = true;

/**
 * The flags to pass to {@link SystemUiHider#getInstance}.
 */
private static final int HIDER_FLAGS = SystemUiHider.FLAG_HIDE_NAVIGATION;

/**
 * The instance of the {@link SystemUiHider} for this activity.
 */
private SystemUiHider mSystemUiHider;

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

    setContentView(R.layout.activity_username);
    ListView outputText = (ListView) findViewById(R.id.listView);

    fetchcontacts();

    final View controlsView = findViewById(R.id.fullscreen_content_controls);
    final View contentView = findViewById(R.id.fullscreen_content);

    // Set up an instance of SystemUiHider to control the system UI for
    // this activity.
    mSystemUiHider = SystemUiHider.getInstance(this, contentView, HIDER_FLAGS);
    mSystemUiHider.setup();
    mSystemUiHider
            .setOnVisibilityChangeListener(new SystemUiHider.OnVisibilityChangeListener() {
                // Cached values.
                int mControlsHeight;
                int mShortAnimTime;

                @Override
                @TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
                public void onVisibilityChange(boolean visible) {
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2) {
                        // If the ViewPropertyAnimator API is available
                        // (Honeycomb MR2 and later), use it to animate the
                        // in-layout UI controls at the bottom of the
                        // screen.
                        if (mControlsHeight == 0) {
                            mControlsHeight = controlsView.getHeight();
                        }
                        if (mShortAnimTime == 0) {
                            mShortAnimTime = getResources().getInteger(
                                    android.R.integer.config_shortAnimTime);
                        }
                        controlsView.animate()
                                .translationY(visible ? 0 : mControlsHeight)
                                .setDuration(mShortAnimTime);
                    } else {
                        // If the ViewPropertyAnimator APIs aren't
                        // available, simply show or hide the in-layout UI
                        // controls.
                        controlsView.setVisibility(visible ? View.VISIBLE : View.GONE);
                    }

                    if (visible && AUTO_HIDE) {
                        // Schedule a hide().
                        delayedHide(AUTO_HIDE_DELAY_MILLIS);
                    }
                }
            });

    // Set up the user interaction to manually show or hide the system UI.
    contentView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if (TOGGLE_ON_CLICK) {
                mSystemUiHider.toggle();
            } else {
                mSystemUiHider.show();
            }
        }
    });

    // Upon interacting with UI controls, delay any scheduled hide()
    // operations to prevent the jarring behavior of controls going away
    // while interacting with the UI.
    findViewById(R.id.dummy_button).setOnTouchListener(mDelayHideTouchListener);
}
public void fetchcontacts() {
    String phonenumber = null;
    String email = null;
    Uri CONTENT_URI = ContactsContract.Contacts.CONTENT_URI;
    String _ID = ContactsContract.Contacts._ID;
    String DISPLAY_NAME = ContactsContract.Contacts.DISPLAY_NAME;
    String HAS_PHONE_NUMBER = ContactsContract.Contacts.HAS_PHONE_NUMBER;
    Uri PhoneCONTENT_URI = ContactsContract.CommonDataKinds.Phone.CONTENT_URI;
    String Phone_CONTACT_ID = ContactsContract.CommonDataKinds.Phone.CONTACT_ID;
    String NUMBER = ContactsContract.CommonDataKinds.Phone.NUMBER;
    Uri EmailCONTENT_URI =  ContactsContract.CommonDataKinds.Email.CONTENT_URI;
    String EmailCONTACT_ID = ContactsContract.CommonDataKinds.Email.CONTACT_ID;
    String DATA = ContactsContract.CommonDataKinds.Email.DATA;

    StringBuffer output = new StringBuffer();
    ContentResolver contentResolver = getContentResolver();
    Cursor cursor = contentResolver.query(CONTENT_URI,null,null,null,null);
    //Loop for every contact in the phone
    if(cursor.getCount() > 0) {
        while (cursor.moveToNext()) {
            String contact_id = cursor.getString(cursor.getColumnIndex( _ID ));
            String name = cursor.getString(cursor.getColumnIndex( DISPLAY_NAME ));
            int hasPhoneNumber = Integer.parseInt(cursor.getString(cursor.getColumnIndex( HAS_PHONE_NUMBER )));
            if (hasPhoneNumber > 0) {
                output.append("\n First Name:" + name);
                // Query and loop for every phone number of the contact
                Cursor phoneCursor = contentResolver.query(PhoneCONTENT_URI,null,Phone_CONTACT_ID + " = ", new String[] { contact_id},null);
                while (phoneCursor.moveToNext()) {
                    phonenumber = phoneCursor.getString(phoneCursor.getColumnIndex(NUMBER));
                    output.append("\n Phone number:" + phonenumber);
                }
                phoneCursor.close();


            }
            output.append("\n");
        }
        outputText.setText(output);
    }
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);

    // Trigger the initial hide() shortly after the activity has been
    // created, to briefly hint to the user that UI controls
    // are available.
    delayedHide(100);
}


/**
 * Touch listener to use for in-layout UI controls to delay hiding the
 * system UI. This is to prevent the jarring behavior of controls going away
 * while interacting with activity UI.
 */
View.OnTouchListener mDelayHideTouchListener = new View.OnTouchListener() {
    @Override
    public boolean onTouch(View view, MotionEvent motionEvent) {
        if (AUTO_HIDE) {
            delayedHide(AUTO_HIDE_DELAY_MILLIS);
        }
        return false;
    }
};

Handler mHideHandler = new Handler();
Runnable mHideRunnable = new Runnable() {
    @Override
    public void run() {
        mSystemUiHider.hide();
    }
};

/**
 * Schedules a call to hide() in [delay] milliseconds, canceling any
 * previously scheduled calls.
 */
private void delayedHide(int delayMillis) {
    mHideHandler.removeCallbacks(mHideRunnable);
    mHideHandler.postDelayed(mHideRunnable, delayMillis);
}
}

Answer 1

setText()对象没有ListView方法，因此outputText.setText()会在method setText not supported for class ListView行引发异常。

也许您将文本设置为错误的对象，或者您的意思是使用Adapter代替？对此的答案需要更多的项目知识。如果您只想显示一个大字符串，请使用TextView对象而不是ListView。

setText中的Android ContactList app错误使用了ListView

1 个答案: