（四）Android布局之帧布局(FrameLayout)

小灰灰 2022-08-06 14:28 176阅读 0赞

<?xml version="1.0" encoding="utf-8"?>
    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="center"
        android:id="@+id/frame">
    
    </FrameLayout>

Activity.java

package com.example.administrator.myapplication;
    
    import android.app.Activity;
    import android.graphics.drawable.Drawable;
    import android.os.Bundle;
    import android.os.Handler;
    import android.os.Message;
    import android.view.Menu;
    import android.view.View;
    import android.widget.FrameLayout;
    
    /**
     * Created by Administrator on 2015/1/29.
     */
    public class BirdActivity extends Activity {
        FrameLayout frame=null;
        private boolean flag=true;
        class MyHandler extends Handler{
            int i=0;
            //由该类两个方法间的循环调用，实现界面不断更新
            public void HandleMessage(Message msg) {
                i++;
                //总共三幅图，依次显示
                show(i % 3);
                //再次调用sleep方法
                sleep(10);
            }
            public void sleep(long delayMillis){
                //判断是否继续飞翔
                    if(flag){
                        //实质上是调用了一次handleMessage
                        sendMessageDelayed(obtainMessage(),delayMillis);
                    }
            }
            }
        //该方法被调用已更新帧布局的前景图片
        void show(int j){
            //获取三张图片
            Drawable a=getResources().getDrawable(R.drawable.a);
            Drawable b=getResources().getDrawable(R.drawable.b);
            Drawable c=getResources().getDrawable(R.drawable.c);
            //不同的情况，设置不同的前景
            switch (j){
                case 0:
                    frame.setForeground(a);
                    break;
                case 1:
                    frame.setForeground(b);
                    break;
                case 3:
                    frame.setForeground(c);
                    break;
            }
        }
        public void onCreate(Bundle saveInstanceState){
            super.onCreate(saveInstanceState);
            setContentView(R.layout.framelayout);
            frame=(FrameLayout)findViewById(R.id.frame);
            //创建一个Handle子类对象，要调用其方法
            final MyHandler myHandler=new MyHandler();
            myHandler.sleep(10);
            //为fram设置单击事件，当其被单击时，切换图片
            frame.setOnClickListener(new View.OnClickListener() {
    
                @Override
                public void onClick(View view) {
                    flag=!flag;
                    myHandler.sleep(10);
                }
            });
    
    
        }
    }