我正在尝试显示onClick
atcardview
按钮,但出现此错误。代码是::
StaggeredGridLayoutManager gridLayoutManager =
new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL);
layoutManager = new GridLayoutManager(getApplicationContext(), 2);
recyclerView = (RecyclerView)findViewById(R.id.cart_recycle);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(gridLayoutManager);
adapter = new NewAdapter(models);
recyclerView.setAdapter(adapter);
name = getResources().getStringArray(R.array.item_name);
price = getResources().getStringArray(R.array.item_cost);
int count = 0;
for(int image:images)
{
NewModel model = new NewModel(image,name[count],price[count]);
count++;
models.add(model);
}
adapter = new NewAdapter(models);
recyclerView.setAdapter(adapter);
button = (Button) findViewById(R.id.addHune);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(v.getContext(), "hello click", Toast.LENGTH_SHORT).show();
add();
}
});
}
日志猫 ::
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
at anish.extras.CartActivity.onCreate(CartActivity.java:78)
at android.app.Activity.performCreate(Activity.java:6303)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1108)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2376)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2483)
我的 XML 代码就像 ::
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:id="@+id/card_view"
android:layout_width="match_parent"
android:layout_height="200dp"
>
<RelativeLayout
android:id="@+id/ll"
android:orientation="vertical"
android:padding="10dp"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<ImageView
android:id="@+id/ItemImage"
android:layout_width="match_parent"
android:layout_height="100dp"
android:src="@drawable/g"
android:scaleType="centerCrop"
/>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:layout_marginBottom="5dp"
android:id="@+id/view"
android:elevation="20dp"
android:layout_below="@+id/ItemImage"
>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Gypsum Board"
android:padding="5dp"
android:id="@+id/ItemName"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="$99"
android:padding="5dp"
android:layout_margin="5dp"
android:layout_below="@+id/ItemName"
android:textStyle="bold"
android:id="@+id/ItemPrice"/>
<Button
android:layout_width="60dp"
android:layout_height="40dp"
android:textSize="10dp"
android:layout_below="@+id/ItemName"
android:id="@+id/addHune"
android:layout_marginRight="10dp"
android:layout_alignParentRight="true"
android:textAllCaps="false"
android:text="+ Add"/>
</RelativeLayout>
</RelativeLayout>
</android.support.v7.widget.CardView>