我正在尝试将名片视图动态添加到滚动视图。所以我将这些卡片视图添加到线性布局中，该布局位于我的xml中的滚动视图内。但是，当我按下fab按钮时，我什么也看不到。我不知道为什么与layoutparams有关吗？
这是我的create.java
public class create extends AppCompatActivity {
Button button;
Context context;
CardView cardview;
LayoutParams layoutparams;
TextView textview;
LinearLayout linearLayout;
ScrollView scrollView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.create);
button = (Button)findViewById(R.id.button);
context = getApplicationContext();
linearLayout = (LinearLayout) findViewById(R.id.linearlayout1);
scrollView = (ScrollView)findViewById(R.id.scrollView1);
//TODO FAB BUTTON
FloatingActionButton floatingActionButton =
(FloatingActionButton) findViewById(R.id.fab);
floatingActionButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
createCardViewProgrammatically();
}
});
}
public void createCardViewProgrammatically(){
CardView card = new CardView(context);
// Set the CardView layoutParams
LayoutParams params = new LayoutParams(
LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT
);
card.setLayoutParams(params);
// Set CardView corner radius
card.setRadius(9);
// Set cardView content padding
card.setContentPadding(15, 15, 15, 15);
// Set a background color for CardView
card.setCardBackgroundColor(Color.parseColor("#FFC6D6C3"));
// Set the CardView maximum elevation
card.setMaxCardElevation(15);
// Set CardView elevation
card.setCardElevation(9);
// Initialize a new TextView to put in CardView
TextView tv = new TextView(context);
tv.setLayoutParams(params);
tv.setText("CardView\nProgrammatically");
tv.setTextSize(TypedValue.COMPLEX_UNIT_DIP, 30);
tv.setTextColor(Color.RED);
// Put the TextView in CardView
card.addView(tv);
// Finally, add the CardView in root layout
linearLayout.addView(card);
}
}
这是我的xml文件
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/colorBackground"
android:minHeight="170dp"
tools:context=".create"
tools:layout_editor_absoluteY="81dp"
>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/scrollView1"
android:layout_width="match_parent"
android:layout_height="438dp"
android:fillViewport="true"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toStartOf="parent"
tools:layout_editor_absoluteY="0dp">
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.android_examples.cardviewprogrammatically_android_examplescom.MainActivity"
android:id="@+id/linearlayout1">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Click here to Create CardView programmatically on Button click"
android:id="@+id/button"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true" />
</LinearLayout>
</ScrollView>
<android.support.design.widget.FloatingActionButton
android:id="@+id/fab"
android:layout_width="60dp"
android:layout_height="70dp"
android:layout_gravity="bottom|end"
android:layout_marginBottom="16dp"
android:layout_marginEnd="16dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="16dp"
android:layout_marginStart="8dp"
android:src="@android:drawable/ic_input_add"
app:backgroundTint="@color/colorCreate"
app:elevation="6dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toStartOf="parent"
app:pressedTranslationZ="12dp"
android:tint="@color/colorBackground"/>
<View
android:id="@+id/subheading"
android:layout_width="match_parent"
android:layout_height="83dp"
android:layout_marginBottom="8dp"
android:layout_marginEnd="1dp"
android:layout_marginLeft="1dp"
android:layout_marginRight="1dp"
android:layout_marginStart="1dp"
android:layout_marginTop="2dp"
android:background="@color/colorBackground"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0"
/>
<View
android:id="@+id/view"
android:layout_width="320dp"
android:layout_height="1dp"
android:layout_marginEnd="8dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="76dp"
android:background="@color/colorText"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<View
android:id="@+id/view2"
android:layout_width="320dp"
android:layout_height="1dp"
android:layout_marginEnd="8dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="28dp"
android:background="@color/colorText"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="12dp"
android:text="@string/done_label"
android:textColor="@color/colorText"
android:textSize="20sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/textView4"
app:layout_constraintTop_toBottomOf="@+id/view2" />
<TextView
android:id="@+id/textView4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:layout_marginEnd="128dp"
android:layout_marginRight="128dp"
android:layout_marginTop="8dp"
android:text="@string/aisle_label"
android:textColor="@color/colorText"
android:textSize="20sp"
app:layout_constraintBottom_toTopOf="@+id/view"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="@+id/view2"
app:layout_constraintVertical_bias="1.0" />
<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:layout_marginEnd="32dp"
android:layout_marginRight="32dp"
android:layout_marginTop="5dp"
android:text="@string/qty_label"
android:textColor="@color/colorText"
android:textSize="20sp"
app:layout_constraintBottom_toTopOf="@+id/view"
app:layout_constraintEnd_toStartOf="@+id/textView4"
app:layout_constraintTop_toBottomOf="@+id/view2"
app:layout_constraintVertical_bias="0.7" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:layout_marginEnd="8dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:text="@string/item_label"
android:textColor="@color/colorText"
android:textSize="20sp"
app:layout_constraintBottom_toTopOf="@+id/view"
app:layout_constraintEnd_toStartOf="@+id/textView3"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/view2"
app:layout_constraintVertical_bias="1.0" />
</android.support.constraint.ConstraintLayout>