CODEWITHSUNDEEP
javaandroidbutton
Codeconuts
Codeconuts

Reputation: 58

setText with onClick button and onCreate crashes app

How do I get my text field to change when the application launches and how do I get it to change again when I click the button?

MainActivity.java

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    TextView myText=(TextView)findViewById(R.id.myActivityTextView);
    myText.setText("Launch Text Change");        
}

public void myButtonclicked(View v){
    TextView myText=(TextView)findViewById(R.id.myActivityTextView);
    myText.setText("Button Change Text");
}

activity_main.xml

<TextView android:text="@string/hello_world" android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/myText" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Change Text"
    android:id="@+id/myButton"
    android:layout_below="@+id/myText"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:onClick="myButtonclicked"/>

Upvotes: 3

Views: 225

Answers (2)

Ebay89
Ebay89

Reputation: 690

The TextView you have in your xml has an id of myText. Change your lookup of 

TextView myText=(TextView)findViewById(R.id.myActivityTextView);

to 

TextView myText=(TextView)findViewById(R.id.myText);

and it should work.

Upvotes: 2

Bojan Kseneman
Bojan Kseneman

Reputation: 15668

You are looking for the wrong id. Here is the correct way

TextView myText=(TextView)findViewById(R.id.myText);
myText.setText("Launch Text Change");

Upvotes: 1

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