CODEWITHSUNDEEP
javaandroidandroid-activity
jkigel
jkigel

Reputation: 1592

Android Change TextView text from another class

I have a TextView in MainActivity, I would like to change the TextView text within another class.

How can I access TextView in MainActivity from another class?

I tried the following

TextView textView = (TextView) findViewById(R.id.myTextView);

textView.setText("Text");

But the app crashes when calling setText()

Upvotes: 3

Views: 12103

Answers (3)

Chintan Raghwani
Chintan Raghwani

Reputation: 3370

You have to use runOnUiThread(new Runnable()...

See following:

import android.content.Context;

private class AnotherClass {
        protected MainActivity context;

        public AnotherClass(Context context){
            this.context = (MainActivity) context;
        }

        public void updateTV(final String str1){
            context.runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    context.textView.setText(str1);    
                }
            });
        }
    }

Upvotes: 9

micha
micha

Reputation: 49552

If you want to update the text of the TextView a possible way would be to edit the text in a common data model that is shared by your classes. If onResume from the activity is called later it can read the new value from the model and update the TextView.

Upvotes: 2

jtt
jtt

Reputation: 13541

I would recommend to use a handler to update the content of that Activity. This is only one way, there is multiple ways to do this.

The entire purpose of a handle is to have some background process/thread passing information into the UI thread.

Upvotes: 1

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