Question

i have developed an app , which uses the settings using Preference Activity and   Action Title Bar . When i press the three dots-> settings button , then it displays not responding , can u help .

清单文件代码是

 <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="demoproject.swatygupta.com.demoproject_actionbar">
<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".Activity2_2PreferenceActivityScreen" />
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name"
        android:theme="@style/AppTheme.NoActionBar">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

菜单文件夹中的xml文件是

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:DemoProject_ActionBar="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context="demoproject.swatygupta.com.demoproject_actionbar.MainActivity">
<item
    android:id="@+id/action_settings"
    android:icon="@android:drawable/ic_menu_manage"
    android:title="@string/action_settings"
    DemoProject_ActionBar:showAsAction="never" />

我开发了一个应用程序，它使用首选项活动和动作标题栏来设置。当我按下三个点 - ＆gt;设置按钮，然后它显示没有响应，你可以帮忙。

主要活动类请在下面找到，请在调用方法时查找是否存在任何错误.-＆gt; public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); fab.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG) .setAction("Action", null).show(); } }); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { int id = item.getItemId(); //noinspection SimplifiableIfStatement if (id == R.id.action_settings) { startActivity(new Intent(this, Activity2_2PreferenceActivityScreen.class)); return true; } return super.onOptionsItemSelected(item);} }

首选项屏幕活动代码 - ＆gt;

public final class Activity2_2PreferenceActivityScreen extends    PreferenceActivity {
   public Activity2_2PreferenceActivityScreen()
{
    super();
} // constructor()

@Override
protected void onCreate(final Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    addPreferencesFromResource(R.xml.preferences);

    // Camera preference
    final ListPreference PreferenceofCamera = (ListPreference) findPreference("camera");

    setCameraPreferences(PreferenceofCamera);

    PreferenceofCamera.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener(){
        @Override
        public boolean onPreferenceClick(Preference preference) {
            setCameraPreferences(PreferenceofCamera);
            return false;
        }
    });

    // JPEG size preference
    final ListPreference PreferenceofSize = (ListPreference) findPreference("size");

    setSizePreferences(PreferenceofSize, PreferenceofCamera);

    PreferenceofSize.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener(){
        @Override
        public boolean onPreferenceClick(Preference preference) {
            setSizePreferences(PreferenceofSize, PreferenceofCamera);
            return false;
        }
    });
} // onCreate(Bundle)

private void setCameraPreferences(final ListPreference cameraPreference)
{
    final int numberOfCameras = Camera.getNumberOfCameras();
    final CharSequence[] entries = new CharSequence[numberOfCameras];
    final CharSequence[] entryValues = new CharSequence[numberOfCameras];
    final Camera.CameraInfo Infoabtcamera = new Camera.CameraInfo();
    for (int cameraIndex = 0; cameraIndex < numberOfCameras; cameraIndex++)
    {
        Camera.getCameraInfo(cameraIndex, Infoabtcamera);
        String cameraFacing;
        switch (Infoabtcamera.facing)
        {
            case Camera.CameraInfo.CAMERA_FACING_BACK:
                cameraFacing = "Back";
                break;
            case Camera.CameraInfo.CAMERA_FACING_FRONT:
                cameraFacing = "Front";
                break;
            default:
                cameraFacing = "unknown";
        } // switch

        entries[cameraIndex] = "Camera " + cameraIndex + " " + cameraFacing;
        entryValues[cameraIndex] = String.valueOf(cameraIndex);
    } //for

    cameraPreference.setEntries(entries);
    cameraPreference.setEntryValues(entryValues);

} // setCameraPreferences(ListPreference)

private void setSizePreferences(final ListPreference sizePreference,
                                final ListPreference cameraPreference)
{
    final String cameraPreferenceValue = cameraPreference.getValue();
    final int cameraIndex;
    if (cameraPreferenceValue != null)
    {
        cameraIndex = Integer.parseInt(cameraPreferenceValue);
    } // if
    else
    {
        cameraIndex = 0;
    } // else
    final Camera camera = Camera.open(cameraIndex);
    final Camera.Parameters params = camera.getParameters();
    camera.release();

    final List<Camera.Size> supportedPreviewSizes = params.getSupportedPreviewSizes();
    CharSequence[] entries = new CharSequence[supportedPreviewSizes.size()];
    CharSequence[] entryValues = new CharSequence[supportedPreviewSizes.size()];
    for (int previewSizeIndex = 0; previewSizeIndex < supportedPreviewSizes.size();
         previewSizeIndex++)
    {
        Camera.Size supportedPreviewSize = supportedPreviewSizes.get(previewSizeIndex);
        entries[previewSizeIndex] = supportedPreviewSize.width + "x"
                + supportedPreviewSize.height;
        entryValues[previewSizeIndex] = String.valueOf(previewSizeIndex);
    } // for

    sizePreference.setEntries(entries);
    sizePreference.setEntryValues(entryValues);

} / setSizePreferenceData(ListPreference)

}`

Answer 1

您可以随时使用工具栏，如下所示

嘿把这段代码放在你的布局文件中。

<android.support.v7.widget.Toolbar
   android:id="@+id/my_toolbar"
   android:layout_width="match_parent"
   android:layout_height="?attr/actionBarSize"
   android:background="?attr/colorPrimary"
   android:elevation="4dp"
   android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
   app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>

并在您的java文件中，此代码应该在那里

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_my);
    Toolbar myToolbar = (Toolbar) findViewById(R.id.my_toolbar);
    setSupportActionBar(myToolbar);
}

特别是这两行

Toolbar myToolbar = (Toolbar) findViewById(R.id.my_toolbar);
setSupportActionBar(myToolbar);

这将向用户显示右上角的软菜单按钮。

手机中没有菜单按钮，无法使用Android应用中的设置选项

1 个答案: