我是Android开发的新手。我创建了一个应用，其中MainActivity包含Gridview图片，ActivityTwo是所选图片的fullscreen视图我正在尝试在操作栏上添加一个后退按钮。图标是可见的，但它不可点击。我还尝试添加其他菜单项，这些项目也可见，但触摸它们时没有任何反应。我也尝试将onClickListener添加到一些帖子中建议的菜单项，但它似乎不起作用。
下面是ActivityTwo代码。
public class ActivityTwo extends ActionBarActivity implements OnClickListener {
protected int currentPosition;
Button share,back;
ImageView imageView;
ViewPager viewPager;
private Toolbar toolbar;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_two);
toolbar= (Toolbar)findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayShowHomeEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
share = (Button)findViewById(R.id.button1);
share.setOnClickListener(this);
back=(Button)findViewById(R.id.button2);
back.setOnClickListener(this);
// get intent data
Intent i = getIntent();
// Selected image id
final int position = i.getExtras().getInt("position");
viewPager = (ViewPager) findViewById(R.id.view_pager);
ImagePagerAdapter adapter = new ImagePagerAdapter();
viewPager.setAdapter(adapter);
viewPager.setCurrentItem(position);
viewPager.setOnPageChangeListener(new OnPageChangeListener() {
@Override
public void onPageSelected(int arg0) {
// TODO Auto-generated method stub
currentPosition = arg0;
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
// TODO Auto-generated method stub
}
@Override
public void onPageScrollStateChanged(int arg0) {
// TODO Auto-generated method stub
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
if
(id==R.id.home)
{
NavUtils.navigateUpFromSameTask(this);
}
return super.onOptionsItemSelected(item);
}
public class ImagePagerAdapter extends PagerAdapter {
Integer[] icons = MainActivity.mThumbIds;
@Override
public int getCount() {
return icons.length;
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == ((ImageView) object);
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
Context context = ActivityTwo.this;
imageView = new ImageView(context);
//ImageView imageView = (ImageView)findViewById(R.id.imageView);
// int padding = context.getResources().getDimensionPixelSize(
// R.dimen.padding_large);
imageView.setPadding(5, 5, 5, 5);
imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
imageView.setImageResource(icons[position]);
imageView.setTag(position);
((ViewPager) container).addView(imageView, 0);
return imageView;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
((ViewPager) container).removeView((ImageView) object);
}
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(v==share){
ImageView Imgv = (ImageView)viewPager.findViewWithTag(viewPager.getCurrentItem());
Drawable mDrawable = Imgv.getDrawable();
Bitmap mBitmap = ((BitmapDrawable)mDrawable).getBitmap();
String path = Images.Media.insertImage(getContentResolver(),
mBitmap, "Image Description", null);
Uri uri = Uri.parse(path);
Intent shareIntent = new Intent();
shareIntent.setAction(Intent.ACTION_SEND);
shareIntent.putExtra(Intent.EXTRA_STREAM, uri);
shareIntent.setType("image/*");
startActivity(Intent.createChooser(shareIntent, "Share Image")); }
if(v==back)
{
finish();
}
}
}
答案 0 :(得分：0)
尝试将此代码添加到工具栏中以便导航
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
onBackPressed();
}
});
对于工具栏中的其他项目
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_settings:
Toast.makeText(context, "setting", Toast.LENGTH_SHORT).show();
break;
case R.id.action_share:
Toast.makeText(context, "share", Toast.LENGTH_SHORT).show();
break;
}
}
希望这个帮助
答案 1 :(得分：0)
要使您的应用图标“可点击”作为后退按钮，您的活动必须遵循父子层次结构。
示例：
通过这种方式，活动A被称为活动B的父活动。
您可以在清单中以XML格式定义此内容，如下所示：
<div class="container" ng-controller="dataController">
...
<select ng-model="selectedOption" ng-change="showData()">
<option ng-repeat="entry in transactions" ng-value="entry.serial">{{ entry.serial }}</option>
</select>
</div>
<div class="col-md-9">
<table class="table table-hover table-striped table-condensed">
...
<tbody>
<tr ng-repeat="entry in dataHistory">
<td>{{ entry.id }}</td>
<td>{{ entry.timestamp | date:"yyyy MMM dd 'at' h:mm:ssa" }}</td>
<td>{{ entry.amount }}</td>
</tr>
</tbody>
</table>
</div>
这将使应用程序图标显示在其左侧的后退箭头（＆lt;）。
然后我们必须处理click事件。
我们在Activity B中的 onOptionsItemSelected 方法中这样做：
...
.controller('dataController', ['$scope', '$firebaseArray', function($scope, $firebaseArray) {
...
$scope.showData = function() {
$scope.dataHistory = [];
transfersRef.orderByChild('serial').equalTo($scope.selectedOption).on('child_added', function(snap) {
transactionsRef.orderByKey().equalTo(snap.val().transactionID).on('child_added', function(data) {
var entry = {};
entry = data.val();
entry.id = data.key();
usersRef.child(entry.fromUserId).child('name').once('value', function(nameSnap) { entry.fromUsername = nameSnap.val(); });
usersRef.child(entry.toUserId).child('name').once('value', function(nameSnap) { entry.toUsername = nameSnap.val(); });
console.log('entry: \n' + entry);
$scope.dataHistory.push(entry);
});
});
};
}])
...
android.R.id.home 是我们正在收听的点击事件的ID。
有时您可能希望模拟后退按钮而不是以意图启动活动A。你可以这样做：
<activity
android:name="com.example.android.ActivityA"
android:label="@string/title_activity_a" />
<activity
android:name="com.example.android.ActivityB"
android:label="@string/title_activity_b"
android:parentActivityName="com.example.android.ActivityA">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.android.ActivityA" />
</activity>