Android Studio 按钮清除 TextView 文本

Question

I want to make a button to clear the TextView text. Im using Android Studio.

ImageButton ImageButton3;
TextView TextView26;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    ImageButton3.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {

            TextView.text="";
        }
    });

Answer 1

You have to instantiate the text view:

ImageButton ImageButton3;
TextView TextView26;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    TextView26 = (TextView) findViewById(R.id.<your text view id>);

    ImageButton3.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {

            TextView26.setText=("");
        }
    });

Answer 2

You forgot to instantiate your views for ImageButton and TextView.

ImageButton ImageButton3;
TextView TextView26;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    ImageButton3 = (ImageButton) findViewById(R.id.myImgBtnId);
    TextView26 = (TextView) findViewById(R.id.myTvId);

    ImageButton3.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {

            TextView26.text="";
        }
    });

Answer 3

I would recommend you to name your variables in camel case.
Also if you can choose a more meaningful name it will be better.

You gotta find BOTH your views before you can manipulate them in your code.

ImageButton imageButton3; //name to clearTextButton?
TextView textView26; 

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

    imageButton3 = (ImageButton) findViewById(R.id.imgButtonId); //replace it with your true id in your xml
    textView26 = (TextView) findViewById(R.id.textViewId);

    imageButton3.setOnClickListener(new View.OnClickListener() {
    public void onClick(View v) {
        textView26.setText("");
    }
});

Answer 4

XML is file code

 <com.google.android.material.textview.MaterialTextView
    android:id="@+id/tx_demo"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Demo World!" />

<com.google.android.material.button.MaterialButton
    android:id="@+id/btnClear"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Clear text Button" />

Java is file code

    txDemo = findViewById(R.id.tx_demo);
    btnClear = findViewById(R.id.btnClear);
    btnClear.setOnClickListener(v -> {
        txDemo.setText("");
    });

OR

    txDemo = findViewById(R.id.tx_demo)
    txDemo = findViewById(R.id.tx_demo)
    btnClear = findViewById<MaterialButton>(R.id.btnClear)
    btnClear.setOnClickListener(View.OnClickListener { v: View? ->
        txDemo!!.text = ""
    })