android EditText focus and out of focus, the input box Listener

 

1. EditText codes by focusing and defocusing

//
 _editText.setFocusable ( to true ); // Set the input box aggregate 
 _editText.setFocusableInTouchMode ( to true ); // a touch focus

 
_editText.requestFocus (); // focusing 
_editText.clearFocus (); // defocus

 

2. EditText monitor changes in the input box

// input box to change the text callback 
 _editText.addTextChangedListener ( new new TextWatcher () {
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        Toast.makeText(EditTextActivity.this, "text change before", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        Toast.makeText(EditTextActivity.this, "text changing", Toast.LENGTH_SHORT).show();
    }

    @Override
    public  void afterTextChanged (the Editable S) {
         // each change, will call back method 
        Toast.makeText (EditTextActivity. the this , "Change After text:" + S, Toast.LENGTH_SHORT) the .Show ();
    }
});

Note: EditText each change, calls the method afterTextChanged

 

3. The complete code

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/white"
    android:gravity="left"
    android:orientation="vertical"
    android:padding="20dp">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:text="Text模式：" />

    <EditText
        android:id="@+id/edit_text_text"
        android:layout_width="300dp"
        android:layout_height="40dp"                        
　　　　  android:background="@drawable/edit_background"
        android:hint="text"
        android:inputType="text"
        android:padding="5dp" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:orientation="horizontal">

        <Button
            android:id="@+id/button_edit_focus"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:padding="10dp"
            android:text="聚焦" />

        <Button
            android:id="@+id/button_edit_blur"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="20dp"
            android:padding="10dp"
            android:text="失焦" />
    </LinearLayout>   

</LinearLayout> 

activity_edit_text.xml

 

package com.example.myapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.example.administrator.myapplication.R;

public class EditTextActivity extends AppCompatActivity {

    private EditText _editText;

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

        _editText = findViewById(R.id.edit_text_text);

        // get the focus and lose focus 
        _editText.setFocusable ( to true );
        _editText.setFocusableInTouchMode(true);

        Button button_focus = findViewById(R.id.button_edit_focus);
        button_focus.setOnClickListener(new EditTextListener());
        Button button_blur = findViewById(R.id.button_edit_blur);
        button_blur.setOnClickListener(new EditTextListener());

        // focus and defocus correction 
        _editText.setOnFocusChangeListener ( new new View.OnFocusChangeListener () {
            @Override
            public void onFocusChange(View v, boolean hasFocus) {
                if(hasFocus) {
                    Toast.makeText(EditTextActivity.this, "text focus", Toast.LENGTH_SHORT).show();
                } else {
                    Toast.makeText(EditTextActivity.this, "text blur", Toast.LENGTH_SHORT).show();
                }
            }
        });
        // input box to change the text callback 
        _editText.addTextChangedListener ( new new TextWatcher () {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                Toast.makeText(EditTextActivity.this, "text change before", Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                Toast.makeText(EditTextActivity.this, "text changing", Toast.LENGTH_SHORT).show();
            }

            @Override
            public  void afterTextChanged (the Editable S) {
                 // each change, will call back method 
                Toast.makeText (EditTextActivity. the this , "Change After text:" + S, Toast.LENGTH_SHORT) the .Show ();
            }
        });
    }

    class EditTextListener implements View.OnClickListener{
        @Override
        public void onClick(View view) {
            switch (view.getId()) {
                case R.id.button_edit_focus :
                    _editText.requestFocus(); //聚焦
                    break;
                case R.id.button_edit_blur:
                    _editText.clearFocus(); //失焦
                    break;
            }
        }
    }
}

EditTextActivity.java