I have a Textview design in activity_main.xml which I want to use for displaying one textview below another. I got this code from stackoverlow itself and made a little change to use the existing Textview design. But the app closes when opened displaying nothing. I'm very new to Android Development.
XML code for TextView:
<TextView
android:id="@+id/textviews"
android:layout_width="match_parent"
android:layout_height="104dp"
android:textSize="30sp" />
Here is the code I got from Stackoverflow:
String[] textArray = {"One", "Two", "Three", "Four"};
LinearLayout linearLayout = new LinearLayout(this);
setContentView(linearLayout);
linearLayout.setOrientation(LinearLayout.VERTICAL);
for( int i = 0; i < textArray.length; i++ )
{
TextView textView = new TextView(this);
textView.setText(textArray[i]);
linearLayout.addView(textView);
}
This code runs perfectly with no issues. But when I tried calling the existing textview design by using findViewById, the code builds but the app never opens. Here it is:
String[] textArray = {"One", "Two", "Three", "Four"};
LinearLayout linearLayout = new LinearLayout(this);
setContentView(linearLayout);
linearLayout.setOrientation(LinearLayout.VERTICAL);
for( int i = 0; i < textArray.length; i++ )
{
TextView textView =(TextView) findViewById(R.id.textviews);
textView.setText(textArray[i]);
linearLayout.addView(textView);
}
How do I use the existing textview design in this code?
Solution:
You just have a slight change in your code, Compare it from below code and try:
String[] textArray = {"One", "Two", "Three", "Four"};
LinearLayout linearLayout = new LinearLayout(this);
setContentView(linearLayout);
linearLayout.setOrientation(LinearLayout.VERTICAL);
for( int i = 0; i < textArray.length; i++ )
{
View v = (View) getLayoutInflater().inflate(R.layout.your_text_view_layout, null);
TextView textView = v.findViewById(R.id.textviews);
textView.setText(textArray[i]);
linearLayout.addView(textView);
}
Hope it works.
You have to inflate TextView Layout, please try below code,
textviews.xml
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/textviews"
android:layout_width="match_parent"
android:layout_height="104dp"
android:textSize="30sp" />
Java Code,
String[] textArray = {"One", "Two", "Three", "Four"};
LinearLayout linearLayout = new LinearLayout(this);
setContentView(linearLayout);
linearLayout.setOrientation(LinearLayout.VERTICAL);
for( int i = 0; i < textArray.length; i++)
{
TextView textView = (TextView) getLayoutInflater().inflate(R.layout.textviews, null);
textView.setText(textArray[i]);
linearLayout.addView(textView);
}
Take Linear Layout in xml,
<LinearLayout
android:id="@+id/linear"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"/>
and add textview in it as
LinearLayout linearLayout = (LinearLayout)findViewById(R.id.linear);
String[] textArray = {"One", "Two", "Three", "Four"};
for( int i = 0; i < textArray.length; i++ )
{
TextView textView = new TextView(this);
textView.setText(textArray[i]);
linearLayout.addView(textView);
}
As you want TextView below the TextView it has to be done by using ListView. First, you have to make a custom adapter layout.
<LinearLayout
android:layout_width="match_parent"
android:layout_height="60dp"
android:background="#cede8a">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20dp"
android:padding="10dp"
android:id="@+id/text"
android:textColor="#000000"
/>
</LinearLayout>
And then make a list view in your layout where you want to show the TextView.
<ListView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/listview"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
In main class you initialise the ListView and store the data in array or other data structure.
public class MainActivity extends AppCompatActivity {
private ListView listView;
private ArrayList<String> al_data = new ArrayList<>();
private Adapter obj_adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = findViewById(R.id.listview);
al_data.add("1234");
al_data.add("1257");
al_data.add("100");
al_data.add("1547");
obj_adapter = new Adapter(al_data);
LinearLayoutManager layoutManager = new LinearLayoutManager(getApplicationContext(),LinearLayoutManager.VERTICAL,false);
listView.setLayoutManager(layoutManager);
listView.setAdapter(obj_adapter);
}
}
And now in the class of the custom adapter write this code.
public class Adapter extends ListView.Adapter<Adapter.MyViewHolder>{
private ArrayList<String> al_data;
public class MyViewHolder extends ListView.ViewHolder{
public TextView textview;
public MyViewHolder (View view){
super(view);
textview = view.findViewById(R.id.text);
}
}
public Adapter(ArrayList<String> al_data) {
this.al_data = al_data;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.adapter_layout,parent,false);
return new MyViewHolder(view);
}
@Override
public void onBindViewHolder(final MyViewHolder holder, int position) {
holder.textview.setText(al_data.get(position));
}
@Override
public int getItemCount() {
return al_data.size();
}
}
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