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程序笔记发布时间：2022-06-07 发布网站：大佬教程 code.js-code.com

大佬教程收集整理的这篇文章主要介绍了Android编程自定义View时添加自己的监听器示例，大佬教程大佬觉得挺不错的，现在分享给大家，也给大家做个参考。

本文实例讲述了AndroID编程自定义view时添加自己的监听器。分享给大家供大家参考，具体如下：

监听器在Java中非常常用，在自定义控件时可能根据自己的需要去监听一些数据的改变，这时就需要我们自己去写监听器，Java中的监听器实际上就是C++中的回调函数，在初始化时设置了这个函数，由某个事件触发这个函数被调用，两个类之间的数据通信也可以通过监听器来实现。要定义监听器就要先定义一个接口，具体功能由设置监听器的类去实现

关键代码实现

package com.example.ListvIEwitem.Widgets;
import androID.content.Context;
import androID.graphics.Canvas;
import androID.util.AttributeSet;
import androID.vIEw.MotionEvent;
import androID.vIEw.VIEw;
/**
 * 在自定义的VIEw中定义三个监听器
 */
public class MyVIEw extends VIEw {
  private OnDownActionListener mDown = null;
  private OnMoveActionListener mMove = null;
  private OnUpActionListener mUp = null;
  public MyVIEw(Context context) {
    super(context);
  }
  public MyVIEw(Context context,AttributeSet attrs) {
    super(context,attrs);
    // Todo auto-generated constructor stub
  }
  @OverrIDe
  protected voID onDraw(Canvas canvas) {
    // Todo auto-generated method stub
    super.onDraw(canvas);
  }
  @OverrIDe
  public @R_262_8487@an ontouchEvent(MotionEvent event) {
    // Todo auto-generated method stub
    int x,y;
    if (event.getAction() == MotionEvent.ACTION_DOWN) {
      x = (int) event.getX();
      y = (int) event.getY();
      if (mDown != null) {
        mDown.onDown(x,y);
      }
      return true; // 只有返回true这个控件的move和up才会响应
    } else if (event.getAction() == MotionEvent.ACTION_MOVE) {
      x = (int) event.getX();
      y = (int) event.getY();
      if (mMove != null) {
        mMove.onMove(x,y);
      }
    } else if (event.getAction() == MotionEvent.ACTION_Up) {
      x = (int) event.getX();
      y = (int) event.getY();
      if (mUp != null) {
        mUp.onUp(x,y);
      }
    }
    return super.ontouchEvent(event);
  }
  // 为每个接口设置监听器
  public voID setonDownActionListener(OnDownActionListener down) {
    mDown = down;
  }
  public voID setonMoveActionListener(OnMoveActionListener movE) {
    mMove = move;
  }
  public voID setonUpActionListener(OnUpActionListener up) {
    mUp = up;
  }
  // 定义三个接口
  public interface OnDownActionListener {
    public voID OnDown(int x,int y);
  }
  public interface OnMoveActionListener {
    public voID OnMove(int x,int y);
  }
  public interface OnUpActionListener {
    public voID OnUp(int x,int y);
  }
}

自定义view在xml中的定义

<?xml version="1.0" enCoding="utf-8"?>
<linearLayout xmlns:androID="http://scheR_525_11845@as.androID.com/apk/res/androID"
  androID:layout_wIDth="match_parent"
  androID:layout_height="match_parent"
  androID:orIEntation="vertical" >
  <com.example.ListvIEwitem.Widgets.MyVIEw
    androID:ID="@+ID/my_vIEw"
    androID:layout_wIDth="wrap_content"
    androID:layout_height="wrap_content"
    androID:BACkground="@drawable/area_poinT_Bg" />
</linearLayout>

Activity中设置监听器

package com.example.ListvIEwitem;
import com.example.ListvIEwitem.Widgets.MyVIEw;
import com.example.ListvIEwitem.Widgets.MyVIEw.onDownActionListener;
import com.example.ListvIEwitem.Widgets.MyVIEw.onMoveActionListener;
import com.example.ListvIEwitem.Widgets.MyVIEw.onUpActionListener;
import androID.app.Activity;
import androID.os.bundle;
public class TestListener extends Activity {
  private MyView view;
  @OverrIDe
  protected voID onCreate(Bundle savedInstanceStatE) {
    // Todo auto-generated method stub
    super.onCreate(savedInstanceStatE);
    setContentVIEw(R.layout.Listener);
    vIEw = (MyVIEw) findVIEwByID(R.ID.my_vIEw);
    vIEw.setonDownActionListener(new OnDownActionListener() {
      @OverrIDe
      public voID OnDown(int x,int y) {
        // Todo auto-generated method stub
        System.out.println("down x = " + x + " y = " + y);
      }
    });
    vIEw.setonMoveActionListener(new OnMoveActionListener() {
      @OverrIDe
      public voID OnMove(int x,int y) {
        // Todo auto-generated method stub
        System.out.println("move x = " + x + " y = " + y);
      }
    });
    vIEw.setonUpActionListener(new OnUpActionListener() {
      @OverrIDe
      public voID OnUp(int x,int y) {
        // Todo auto-generated method stub
        System.out.println("up x = " + x + " y = " + y);
      }
    });
  }
}