android EditText 的聚焦和失焦，输入框的监听

 

1. EditText通过代码聚焦和失焦

//
 _editText.setFocusable(true);//设置输入框可聚集
 _editText.setFocusableInTouchMode(true);//设置触摸聚焦

 
_editText.requestFocus(); //聚焦
_editText.clearFocus(); //失焦

 

2. EditText输入框改变监听

//输入框文本改变的回调
 _editText.addTextChangedListener(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(Editable s) {
        // 每次改变，会回调此方法
        Toast.makeText(EditTextActivity.this, "text change after：" + s, Toast.LENGTH_SHORT).show();
    }
});

注意：EditText每次改变，会调用 afterTextChanged 方法

 

3. 完整代码

<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