将动态按钮添加到视图中并永久保存

Question

我有一个带有此视图的片段：

XML:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:tag="general"
android:id="@+id/root"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#343535"
android:orientation="vertical"
tools:context=".fragments.GeneralFragment">
<Button
android:id="@+id/hello"
android:layout_width="match_parent"
android:layout_height="60dp"
android:gravity="center_vertical"
android:onClick="onClick"
android:text="@string/hello" />
<Button
android:id="@+id/observed"
android:layout_width="match_parent"
android:layout_height="60dp"
android:gravity="center_vertical"
android:onClick="onClick"
android:text="@string/observed" />
<Button
android:id="@+id/thanks"
android:layout_width="match_parent"
android:layout_height="60dp"
android:gravity="center_vertical"
android:onClick="onClick"
android:text="@string/thanks" />
</LinearLayout>

共有3个按钮。每当你点击其中一个，它的文本就会显示出来。

现在我想添加另一个动态按钮。应将其添加到@+id/hello之前。

我用试过了

LinearLayout root = (LinearLayout) view.findViewById(R.id.root);
root.addView();

但它看起来完全错误，因为缺少一些参数。

例如，新按钮应该是这样的：

XML:

<Button
android:layout_width="match_parent"
android:layout_height="60dp"
android:gravity="center_vertical"
android:onClick="onClick"
android:text="I am a dynamic text" />

此按钮应永久保存在应用程序中。我该怎么做？

更新

我正在使用一个对话框，所以这是类：

@SuppressLint("ValidFragment")
public class Dialog extends DialogFragment {
private final int _layout;
private TextInputEditText _customTextField;
@SuppressLint("ValidFragment")
public Dialog(int layout) {
_layout = layout;
}
public interface ICustomTts {
void customTts(String input, Activity activity);
}
public ICustomTts iCustomTts;
public interface  ITarget {
void getTarget(String input);
}
public ITarget iTarget;
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
final View view =  inflater.inflate(_layout, container, false);
// Display fragment_custom
if (_layout == R.layout.fragment_custom) {
_customTextField = view.findViewById(R.id.customTextField);
Button _customBtn = view.findViewById(R.id.customCta);
_customBtn.setOnClickListener(new View.OnClickListener() {
@RequiresApi(api = Build.VERSION_CODES.M)
@Override
public void onClick(View view) {
Log.d(TAG, "onClick: Clicked on CTA of custom");
String input = _customTextField.getText().toString();
if (!input.equals("")) {
iCustomTts.customTts(input, getActivity());
_dismiss();
}
}
});
MaterialCheckBox customeSave = view.findViewById(R.id.customSave);
customeSave.setOnClickListener(new View.OnClickListener() {
@RequiresApi(api = Build.VERSION_CODES.M)
@Override
public void onClick(View v) {
Log.d(TAG, "customeSave was clicked!");
LinearLayout root = view.findViewById(R.id.root);
Button button = new Button(getContext());
float heightInPixel = 60 * getResources().getDisplayMetrics().density;
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, (int) heightInPixel);
params.gravity = Gravity.CENTER;
button.setText("I am a dynamic text");
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// Do the stuff on the click
}
});
root.addView(button, 0);
}
});
}
// Display fragment_target
if (_layout == R.layout.fragment_target) {
_customTextField = view.findViewById(R.id.targetTextField);
Button _customBtn = view.findViewById(R.id.targetCta);
_customBtn.setOnClickListener(new View.OnClickListener() {
@RequiresApi(api = Build.VERSION_CODES.M)
@Override
public void onClick(View view) {
Log.d(TAG, "onClick: Clicked on CTA of target");
String input = _customTextField.getText().toString();
if (!input.equals("")) {
iTarget.getTarget(input);
_dismiss();
}
}
});
}
return view;
}
/**
* Dismissing the dialog
*/
private void _dismiss() {
this.dismiss();
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
try {
if (_layout == R.layout.fragment_custom) {
iCustomTts = (ICustomTts) getActivity();
}
else if (_layout == R.layout.fragment_target) {
iTarget = (ITarget) getActivity();
}
}
catch (ClassCastException e) {
Log.e(TAG, "onAttach: ClassCastException: " + e.getMessage());
}
}
}

Answer 1

您需要使用addView()的双参数版本来确定LinearLayout:中按钮的顺序(索引(

LinearLayout root = view.findViewById(R.id.root);
Button button = new Button(requireContext());
float heightInPixel = 60 * getResources().getDisplayMetrics().density;
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, (int) heightInPixel);
params.gravity = Gravity.CENTER;
button.setText("I am a dynamic text");
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// Do the stuff on the click
}
});
root.addView(button, 0);