package com.geli_2.sujie.sujiegeili2testbutton;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.Button;import android.widget.Toast;public class MainActivity extends AppCompatActivity implements View.OnClickListener{  private Button mBtClick;  private Button mBtClick2;  private Button mBtClick3;  private Button mBtClick4;  @Override  protected void onCreate(Bundle savedInstanceState)  {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    mBtClick = (Button) findViewById(R.id.btnTest1);      //1、fdv 找到button id                                  // 2、 Alt Ctrl F 形成類全局Field    mBtClick.setOnClickListener(new View.OnClickListener()   //3、鍵入此行代碼自動嵌入內部類方法    {      @Override      public void onClick(View v)      {                            //4、 Toast tab tab 調出toast 方法 以上為方法一        Toast.makeText(MainActivity.this, "hello world", Toast.LENGTH_SHORT).show();      }    });    mBtClick2 = (Button) findViewById(R.id.btnSample2);     //5、找出button 2 的 button id  fdv    mBtClick2.setOnClickListener(new Button_2_OnClickListener()); //9、實例化方法給button 綁定 以上是方法二    mBtClick3 = (Button) findViewById(R.id.btnTry3);      //10、找出button 3 的 button id  fdv    mBtClick3.setOnClickListener(this);             //11、 this 表示 main acitivity                                  //12 但是這里是方法參數是onclicklistener接口，此處 this Alt Enter 會在此方法上加上實現的接口    mBtClick4 = (Button) findViewById(R.id.btnExample4);    //5、找出button 4 的 button id  fdv  }  /**   * Called when a view has been clicked.   *   * @param v The view that was clicked.   */  @Override  public void onClick(View v)  {    //方法三  }  class Button_2_OnClickListener implements View.OnClickListener //6、設置一個 click 方法 命名后繼承自 view                                  // onclicklistener                                  //7、 后在 繼承 implements 上 alt + enter 來實現方法  {    /**     * Called when a view has been clicked.     *     * @param v The view that was clicked.     */    @Override    public void onClick(View v)    {      //方法二    }  }  public void click(View view)  {    //方法四  }}