Develop Reference

How to create a new "TextView" object,by concatenating two strings?

I want to create a new "TextView" object in "MainActivity" code by concatenating
Two String names. for example:
String s1 = "num";
String s2 = "ber";
String s3 = s1+s2;
TextView s3 = new TextView(this);
How cast s3 to TextView object,so i dont get anyy error,code above?
I mean i want to use s3 as a "TextView" name object.

You would do something like this.
TextView textView = new TextView(this);
textView.setText(s3);
or
TextView s3 = new TextView(this);
s3.setText(s1 + s2);
or programmatically in a loop
for (int i = 0; i < list.size(); i++) {
TextView textView = new TextView(this);
textView.setId(s3); //set textview id, this WILL NOT make it a variable of 'number'
linearLayout.addView(textView);
}

First problem is you declared 2 variables with the same name. Fix it by giving TextView a better name and then as #soldforapp answered already, set the text using the method .setText();
edit:
Wait, so you want to assign the value of the TextView to the string variable s3?
I don't really understand your problem. If so, if your code would look like this (so it runs)
String s1 = "num";
String s2 = "ber";
String s3 = s1+s2;
TextView tv = new TextView(this);
This line will assign the variable s3 the text inside your TextView.
s3 = tv.getText().toString();

Using the same name for the different variable in one scope is not possible in JAVA. (even with different types)
Using StringBuilder is better option than concatenating with + operation, so:
String s1 = "num";
String s2 = "ber";
String concat = new StringBuilder().append(s1).append(s2).toString();
TextView s3 = new TextView(this);
s3.setText(concat);
Edit:
What you want is not as easy as what exists in script languages like PHP but you can do it with reflection with efforts. But there is an easier option with using Map:
Map<String,TextView> map = new HashMap<>();
map.put(concat, new TextView(this));
You can get the TextViews with:
map.get(concat).setText("Your String");

To split Strings from a MultiAutoCompleteTextView and set it to different textview

I have a array of strings which is a resultant of options selected from a MultiAutoCompleteTextView using the comma tokenizer. The string appears as below:
"India, China, Japan, America, Australia"
I need to seperate this values based on the coma positiona and set those values to different textview's. Also I need to restrict the users to select only 5 values and those values should not be repeated.

You can use String.split() like this:
String[] array = yourString.split(",");
And iterate through that array.
EDIT:
To check if the user already selected the item, you can add an OnItemClickListener to your multiAutoCompleteTextView and have a HashSet or a Set where your items clicked are stored and check if this item already exists in the set
Example:
Initialize your HashSet first: HashSet<String> hashset = new HashSet<String>();
And later:
youMultiAutoCompleteTv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String itemClicked = parent.getAdapter().getItem(position).toString();
if(hashset.contains(itemClicked)){
Toast.makeText(getApplicationContext(), "Item exists", Toast.LENGTH_SHORT).show();
}
else {
hashset.add(itemClicked);
}
}
});

Use something like this:
String myListAsString = "India, China, Japan, America, Australia";
String[] countries = myListAsString.split(",");
TextView t1 = (TextView)findViewById(R.id.t1);
TextView t2 = (TextView)findViewById(R.id.t2);
TextView t3 = (TextView)findViewById(R.id.t3);
TextView t4 = (TextView)findViewById(R.id.t4);
TextView t5 = (TextView)findViewById(R.id.t5);
t1.setText(countries[0]);
t2.setText(countries[1]);
t3.setText(countries[2]);
t4.setText(countries[3]);
t5.setText(countries[4]);

You can use this :
String input = editText.getText().toString().trim(); //Getting String from view.
String[] singleInputs = input.split("\\s*,\\s*"); //Splitting in proper way.

Obscure issue with string formatting from SQLite database

I appreciate there's a lot of helpful stack questions and answers to my question but I'm running into problems I've not had in the past.
The Problem:
I am using a cursor to populate textviews in rows on a view (without using listview - that's crazy I know). I am trying to format the string value(s) taken from from the database column STUDENT_POINTS that are put into a textview tpoints. Here is the code I am using:
public void bindView(View v, final Context context, Cursor c) {
final int id = c.getInt(c.getColumnIndex(Students.STUDENT_ID));
final String name = c.getString(c.getColumnIndex(Students.STUDENT_NAME));
final String age = c.getString(c.getColumnIndex(Students.STUDENT_AGE));
final String points = c.getString(c.getColumnIndex(Students.STUDENT_POINTS));
final String teachernote = c.getString(c.getColumnIndex(Students.TEACHERNOTE));
final byte[] image = c.getBlob(c.getColumnIndex(Students.IMAGE));
ImageView iv = (ImageView) v.findViewById(R.id.photo);
if (image != null) {
if (image.length > 3) {
iv.setImageBitmap(BitmapFactory.decodeByteArray(image, 0,image.length));
}
}
TextView tname = (TextView) v.findViewById(R.id.name);
tname.setText(name);
TextView tage = (TextView) v.findViewById(R.id.age);
tage.setText(age);
TextView tpoints = (TextView) v.findViewById(R.id.points);
tpoints.setText(String.format(points, "%1$,.2f"));
final StudentsConnector sqlCon = new StudentsConnector(context);
The rest of bindView is for buttons so I have not included it here. The problem is with the line:
tpoints.setText(String.format(points, "%1$,.2f"));
I'm intending to have commas to separate out large numbers but this does nothing! If anybody has the time could you please tell me what I'm doing wrong?
Thanks in advance.

You have your two parameters backwards-- you should have the format string followed by the data string: String.format("%1$,.2f", points );
This formatted nicely for me with this little snippet in my code:
double points = 56789.45f;
String boogie = String.format("%1$,.2f", points );
and it generated a number 56,789.45
But bigger numbers don't work well due to precision in the formater. You may want to split the mantissa off of their, format them separately and combine them.

Android: adding multiple Views programmatically

I want to add a LinearLayout wrapped around a TextView and Button programmatically. I want it to take a String array and then using the length of the string array, add that many TextViews each with their own button.
So first:
String [] s = { .... the values ....}
int sL = s.length;
TextView t1 = new TextView (this);
// then somehow create t2, t3... etc. matching the length of the String array.
Is this the best way to do this or is there another way to do this? For some context, it's a quiz app and I've created a list of categories inside resources as values and I'm trying to programmatically get my app to create as many TextViews as there are categories then set each TextView to each category then get each button to take the user to that category of questions.

You are starting it right, just do a for loop and add textviews to your linearlayout.
// You linearlayout in which you want your textview
LinearLayout linearLayout = (LinearLayout) findViewById(R.id.mylayout);
linearLayout.setBackgroundColor(Color.TRANSPARENT);
String [] s = { .... the values ....}
int sL = s.length;
TextView textView = null;
// For later use if you'd like
ArrayList<TextView> tViews = new ArrayList<TextView>();
for (int i = 0; i < sL; i++)
{
textView = new TextView(this);
textView.setText(s[i]);
linearLayout.addView(textView);
tViews.add(textView);
}
There is nothing wrong with this way of doing it. If you want to use these textview later on (set text for them or something) store them in an Array of some kind. Edited code

You can do the following:
for(int i=0;i<s.length;i++){
TextView t=new TextView(this);
t.setText(s[i]);
yourLinearLayout.addView(t);
}
But I really think that using a ListView would be better for performance ;)

Set text color of a textview in a listview item? (Android)

Been scouring this site for any answers, no real easy solution I've found for this. I am creating an Android application that uses an sqlite database to look up a hex value by the color name typed in. I am dynamically creating a TextView, setting its text and text color, then adding it to the ArrayList, then the ArrayList is being added to the ListView. The text shows up in the ListView, but its color property is not being set. I'd really like to find a way to get the text color set for each listview item. Here is my code thus far:
Class Variables:
private ListView lsvHexList;
private ArrayList<String> hexList;
private ArrayAdapter adp;
In onCreate():
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.color2hex);
lsvHexList = (ListView) findViewById(R.id.lsvHexList);
hexList = new ArrayList<String>();
In my Button Handler:
public void btnGetHexValueHandler(View view) {
// Open a connection to the database
db.openDatabase();
// Setup a string for the color name
String colorNameText = editTextColorName.getText().toString();
// Get all records
Cursor c = db.getAllColors();
c.moveToFirst(); // move to the first position of the results
// Cursor 'c' now contains all the hex values
while(c.isAfterLast() == false) {
// Check database if color name matches any records
if(c.getString(1).contains(colorNameText)) {
// Convert hex value to string
String hexValue = c.getString(0);
String colorName = c.getString(1);
// Create a new textview for the hex value
TextView tv = new TextView(this);
tv.setId((int) System.currentTimeMillis());
tv.setText(hexValue + " - " + colorName);
tv.setTextColor(Color.parseColor(hexValue));
hexList.add((String) tv.getText());
} // end if
// Move to the next result
c.moveToNext();
} // End while
adp = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, hexList);
lsvHexList.setAdapter(adp);
db.close(); // close the connection
}

You are not adding the created TextView to the list at all, you just add the String to the list, thus it doesn't matter what method you called on the TextView:
if(c.getString(1).contains(colorNameText)) {
// ...
TextView tv = new TextView(this);
tv.setId((int) System.currentTimeMillis());
tv.setText(hexValue + " - " + colorName);
tv.setTextColor(Color.parseColor(hexValue));
hexList.add((String) tv.getText()); // apend only the text to the list
// !!!!!!!!!!!!!! lost the TextView !!!!!!!!!!!!!!!!
}
What you need to do is to store the colors in another array, and when creating the actual list view, set the color of each TextView according to the appropriate value in the list.
To do that, you will need to extend ArrayAdapter and add the logic of the TextView color inside.