情景描述
有時，我們在開發Android中遇到模擬軟鍵盤的刪除鍵一樣的功能,即通過“刪除”按鈕去刪除EditText單個字元。

方法就一句話：
editText.dispatchKeyEvent(new KeyEvent(
KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_DEL));
就能達到跟軟鍵盤刪除鍵一樣的刪除效果。

程式碼區：
Xml中

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
 
 xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="testwebricheditor.demo.com.richeditor.MainActivity"
 
>

    <EditText
        android:id="@+id/et"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
 

        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/delete"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="delete"
        android:textColor="#ff00ff"
        android:textSize="18sp" />

</android.support.constraint.ConstraintLayout>

activity中

package testwebricheditor.demo.com.richeditor;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class MainActivity extends AppCompatActivity {

    EditText editText;
    Button delete;

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

        editText = findViewById(R.id.et);

        delete = findViewById(R.id.delete);

        delete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                editText.dispatchKeyEvent(new KeyEvent(
                        KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_DEL));
            }
        });

    }


}

如果有問題的話 請檢查自定義控制元件寫法或者邏輯問題。