Java 按下操作栏上的后退按钮后,RecyclerView不显示
您好,我正在构建一个应用程序,其中Main活动显示一些类别的GridView。单击每个类别时,另一个活动(GridItemActivity)将打开一些RecyclerView。此外,单击RecyclerView时,GalleryActivity将打开以显示所选列表的内容(ImageView和TextView)。在清单文件中,我设置了每个活动的父级,如下所示: AndroidManifest.xmlJava 按下操作栏上的后退按钮后,RecyclerView不显示,java,android,gridview,android-recyclerview,Java,Android,Gridview,Android Recyclerview,您好,我正在构建一个应用程序,其中Main活动显示一些类别的GridView。单击每个类别时,另一个活动(GridItemActivity)将打开一些RecyclerView。此外,单击RecyclerView时,GalleryActivity将打开以显示所选列表的内容(ImageView和TextView)。在清单文件中,我设置了每个活动的父级,如下所示: AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?> <
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.gridrecycler">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".GalleryActivity">
<meta-data android:name="android.support.PARENT_ACTIVITY"
android:value=".GridItemActivity"/>
</activity>
<activity android:name=".GridItemActivity" >
<meta-data android:name="android.support.PARENT_ACTIVITY"
android:value=".MainActivity"/>
</activity>
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
对不起,我的问题问得太多了。提前感谢。对于问题一(1),这解决了问题
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
onBackPressed();
return true;
}
return super.onOptionsItemSelected(item);
}
对于第二个,这有帮助
public ViewHolder(@NonNull View itemView, Context context, int[] images, ArrayList<String> mImageNames) {
super(itemView);
image = itemView.findViewById(R.id.image);
imageName = itemView.findViewById(R.id.image_name);
parentLayout = itemView.findViewById(R.id.parent_layout);
itemView.setOnClickListener(this);
this.context = context;
this.images = images;
this.mImageNames = mImageNames;
}
@Override
public void onClick(View v) {
Intent intent = new Intent(mContext, GalleryActivity.class);
intent.putExtra("image_url", mImages[getAdapterPosition()]);
intent.putExtra("image_name", mImageNames.get(getAdapterPosition()));
mContext.startActivity(intent);
}
public ViewHolder(@NonNull View itemView,Context Context,int[]image,ArrayList mImageNames){
超级(项目视图);
image=itemView.findviewbyd(R.id.image);
imageName=itemView.findViewById(R.id.image\u名称);
parentLayout=itemView.findviewbyd(R.id.parent\u布局);
setOnClickListener(这个);
this.context=上下文;
这个。图像=图像;
this.mImageNames=mImageNames;
}
@凌驾
公共void onClick(视图v){
意向意向=新意向(mContext,GalleryActivity.class);
putExtra(“image_url”,mImages[getAdapterPosition()]);
intent.putExtra(“image_name”,mImageNames.get(getAdapterPosition());
mContext.startActivity(意图);
}
对于问题一(1),这解决了问题
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
onBackPressed();
return true;
}
return super.onOptionsItemSelected(item);
}
对于第二个,这有帮助
public ViewHolder(@NonNull View itemView, Context context, int[] images, ArrayList<String> mImageNames) {
super(itemView);
image = itemView.findViewById(R.id.image);
imageName = itemView.findViewById(R.id.image_name);
parentLayout = itemView.findViewById(R.id.parent_layout);
itemView.setOnClickListener(this);
this.context = context;
this.images = images;
this.mImageNames = mImageNames;
}
@Override
public void onClick(View v) {
Intent intent = new Intent(mContext, GalleryActivity.class);
intent.putExtra("image_url", mImages[getAdapterPosition()]);
intent.putExtra("image_name", mImageNames.get(getAdapterPosition()));
mContext.startActivity(intent);
}
public ViewHolder(@NonNull View itemView,Context Context,int[]image,ArrayList mImageNames){
超级(项目视图);
image=itemView.findviewbyd(R.id.image);
imageName=itemView.findViewById(R.id.image\u名称);
parentLayout=itemView.findviewbyd(R.id.parent\u布局);
setOnClickListener(这个);
this.context=上下文;
这个。图像=图像;
this.mImageNames=mImageNames;
}
@凌驾
公共void onClick(视图v){
意向意向=新意向(mContext,GalleryActivity.class);
putExtra(“image_url”,mImages[getAdapterPosition()]);
intent.putExtra(“image_name”,mImageNames.get(getAdapterPosition());
mContext.startActivity(意图);
}
public ViewHolder(@NonNull View itemView, Context context, int[] images, ArrayList<String> mImageNames) {
super(itemView);
image = itemView.findViewById(R.id.image);
imageName = itemView.findViewById(R.id.image_name);
parentLayout = itemView.findViewById(R.id.parent_layout);
itemView.setOnClickListener(this);
this.context = context;
this.images = images;
this.mImageNames = mImageNames;
}
@Override
public void onClick(View v) {
Intent intent = new Intent(mContext, GalleryActivity.class);
intent.putExtra("image_url", mImages[getAdapterPosition()]);
intent.putExtra("image_name", mImageNames.get(getAdapterPosition()));
mContext.startActivity(intent);
}