android 图片滑动控件

Posted 2020-10-06

本次的随笔记录学习了ImageSwitcher  和 Gallery

ImageSwitcher ：

   ImageSwitcher粗略的理解就是ImageView的选择器

   ImageSwitcher的原理：ImageSwitcher有两个子View：ImageView，当左右滑动的时候，就在这两个ImageView之间来回切换来显示图片

可以查看ImageSwitcher.java 的源代码同时还是要结合ViewSwitcher .java来理解：

ImageSwitcher.java

/*
 * Copyright (C) 2006 The android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.widget;

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.util.AttributeSet;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;


public class ImageSwitcher extends ViewSwitcher
{
    public ImageSwitcher(Context context)
    {
        super(context);
    }
    
    public ImageSwitcher(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public void setImageResource(int resid)
    {
        ImageView image = (ImageView)this.getNextView();
        image.setImageResource(resid);
        showNext();
    }

    public void setImageURI(Uri uri)
    {
        ImageView image = (ImageView)this.getNextView();
        image.setImageURI(uri);
        showNext();
    }

    public void setImageDrawable(Drawable drawable)
    {
        ImageView image = (ImageView)this.getNextView();
        image.setImageDrawable(drawable);
        showNext();
    }

    @Override
    public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
        super.onInitializeAccessibilityEvent(event);
        event.setClassName(ImageSwitcher.class.getName());
    }

    @Override
    public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
        super.onInitializeAccessibilityNodeInfo(info);
        info.setClassName(ImageSwitcher.class.getName());
    }
}

View Code

 

ViewSwitcher .java

/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.widget;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;

/**
 * {@link ViewAnimator} that switches between two views, and has a factory
 * from which these views are created.  You can either use the factory to
 * create the views, or add them yourself.  A ViewSwitcher can only have two
 * child views, of which only one is shown at a time.
 */
public class ViewSwitcher extends ViewAnimator {
    /**
     * The factory used to create the two children.
     */
    ViewFactory mFactory;

    /**
     * Creates a new empty ViewSwitcher.
     *
     * @param context the application‘s environment
     */
    public ViewSwitcher(Context context) {
        super(context);
    }

    /**
     * Creates a new empty ViewSwitcher for the given context and with the
     * specified set attributes.
     *
     * @param context the application environment
     * @param attrs a collection of attributes
     */
    public ViewSwitcher(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    /**
     * {@inheritDoc}
     *
     * @throws IllegalStateException if this switcher already contains two children
     */
    @Override
    public void addView(View child, int index, ViewGroup.LayoutParams params) {
        if (getChildCount() >= 2) {
            throw new IllegalStateException("Can‘t add more than 2 views to a ViewSwitcher");
        }
        super.addView(child, index, params);
    }

    @Override
    public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
        super.onInitializeAccessibilityEvent(event);
        event.setClassName(ViewSwitcher.class.getName());
    }

    @Override
    public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
        super.onInitializeAccessibilityNodeInfo(info);
        info.setClassName(ViewSwitcher.class.getName());
    }

    /**
     * Returns the next view to be displayed.
     *
     * @return the view that will be displayed after the next views flip.
     */
    public View getNextView() {
        int which = mWhichChild == 0 ? 1 : 0;
        return getChildAt(which);
    }

    private View obtainView() {
        View child = mFactory.makeView();
        LayoutParams lp = (LayoutParams) child.getLayoutParams();
        if (lp == null) {
            lp = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
        }
        addView(child, lp);
        return child;
    }

    /**
     * Sets the factory used to create the two views between which the
     * ViewSwitcher will flip. Instead of using a factory, you can call
     * {@link #addView(android.view.View, int, android.view.ViewGroup.LayoutParams)}
     * twice.
     *
     * @param factory the view factory used to generate the switcher‘s content
     */
    public void setFactory(ViewFactory factory) {
        mFactory = factory;
        obtainView();
        obtainView();
    }

    /**
     * Reset the ViewSwitcher to hide all of the existing views and to make it
     * think that the first time animation has not yet played.
     */
    public void reset() {
        mFirstTime = true;
        View v;
        v = getChildAt(0);
        if (v != null) {
            v.setVisibility(View.GONE);
        }
        v = getChildAt(1);
        if (v != null) {
            v.setVisibility(View.GONE);
        }
    }

    /**
     * Creates views in a ViewSwitcher.
     */
    public interface ViewFactory {
        /**
         * Creates a new {@link android.view.View} to be added in a
         * {@link android.widget.ViewSwitcher}.
         *
         * @return a {@link android.view.View}
         */
        View makeView();
    }
}

View Code

所以需要最基本的

myswitch.setFactory(new ViewFactory() {
@Override
public View makeView() {
ImageView imageView=new ImageView(MainActivity.this);
return imageView;
}
});
myswitch.setImageResource(imgId[0]);

 

来设置ImageViewSwitcher

Gallery

主要涉及到的代码如下：

Gallery myGalley=(Gallery) findViewById(R.id.myGallery);
        BaseAdapter baseAdp=new BaseAdapter() {
            
            @SuppressWarnings("deprecation")
            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                ImageView imageView=new ImageView(MainActivity.this);
                imageView.setScaleType(ScaleType.FIT_XY);
                imageView.setLayoutParams(new Gallery.LayoutParams(100, 100));
                imageView.setImageResource(imgId[position%imgId.length]);
                return imageView;
            }
            
            @Override
            public long getItemId(int position) {
                return position;
            }
            
            @Override
            public Object getItem(int position) {
                return imgId[position];
            }
            
            @Override
            public int getCount() {
                return imgId.length*3;
                /*return Integer.MAX_VALUE;*/
            }
        };
        myGalley.setAdapter(baseAdp);
        myGalley.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                myswitch.setImageResource(imgId[position%imgId.length]);
                
                
            }
        });

View Code

 

 

完整代码如下

显示结果：

代码如下：

MainActivity.java

 1 package com.example.imgswitch;
 2 
 3 import android.app.Activity;
 4 import android.os.Bundle;
 5 import android.view.Menu;
 6 import android.view.MenuItem;
 7 import android.view.View;
 8 import android.view.ViewGroup;
 9 import android.view.View.OnClickListener;
10 import android.view.ViewGroup.LayoutParams;
11 import android.widget.AdapterView;
12 import android.widget.AdapterView.OnItemClickListener;
13 import android.widget.BaseAdapter;
14 import android.widget.Gallery;
15 import android.widget.ImageSwitcher;
16 import android.widget.ImageView;
17 import android.widget.ImageView.ScaleType;
18 import android.widget.ViewSwitcher.ViewFactory;
19 
20 
21 public class MainActivity extends Activity {
22  private int[] imgId=new int[]{ R.drawable.food1,R.drawable.food2,R.drawable.food3,R.drawable.food4};
23  private int option=0;
24  @Override
25     protected void onCreate(Bundle savedInstanceState) {
26         super.onCreate(savedInstanceState);
27         setContentView(R.layout.activity_main);
28         final ImageSwitcher myswitch=(ImageSwitcher) findViewById(R.id.myImgswitch);
29         myswitch.setFactory(new ViewFactory() {
30             @Override
31             public View makeView() {
32                 ImageView imageView=new ImageView(MainActivity.this);
33                 return imageView;
34             }
35         });
36         myswitch.setImageResource(imgId[0]);
37        /* myswitch.setOnClickListener(new OnClickListener() {
38             
39             @Override
40             public void onClick(View v) {
41                 option++;
42                 myswitch.setImageResource(imgId[option%imgId.length]);
43                 
44             }
45         }); 这个是直接点击图片就可以切换，没有和画廊关联*/
46         
47  
48         @SuppressWarnings("deprecation")
49         Gallery myGalley=(Gallery) findViewById(R.id.myGallery);
50         BaseAdapter baseAdp=new BaseAdapter() {
51             
52             @SuppressWarnings("deprecation")
53             @Override
54             public View getView(int position, View convertView, ViewGroup parent) {
55                 ImageView imageView=new ImageView(MainActivity.this);
56                 imageView.setScaleType(ScaleType.FIT_XY);
57                 imageView.setLayoutParams(new Gallery.LayoutParams(100, 100));
58                 imageView.setImageResource(imgId[position%imgId.length]);
59                 return imageView;
60             }
61             
62             @Override
63             public long getItemId(int position) {
64                 return position;
65             }
66             
67             @Override
68             public Object getItem(int position) {
69                 return imgId[position];
70             }
71             
72             @Override
73             public int getCount() {
74                 return imgId.length*3;
75                 /*return Integer.MAX_VALUE;这里可以设置控制循环次数*/
76             }
77         };
78         myGalley.setAdapter(baseAdp);
79         myGalley.setOnItemClickListener(new OnItemClickListener() {
80 
81             @Override
82             public void onItemClick(AdapterView<?> parent, View view,
83                     int position, long id) {
84                 myswitch.setImageResource(imgId[position%imgId.length]);
85                 
86                 
87             }
88         });
89     }
90 
91     @Override
92     public boolean onCreateOptionsMenu(Menu menu) {
93         // Inflate the menu; this adds items to the action bar if it is present.
94         getMenuInflater().inflate(R.menu.main, menu);
95         return true;
96     }
97 
98 }

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.imgswitch.MainActivity" >

   <ImageSwitcher 
       android:inAnimation="@android:anim/fade_in"
       android:outAnimation="@android:anim/fade_out"
       android:id="@+id/myImgswitch"
       android:layout_width="240dp"
       android:layout_height="240dp"></ImageSwitcher>
   <Gallery
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:gravity="bottom"
       android:id="@+id/myGallery"
       android:unselectedAlpha="0.4"></Gallery>"

</LinearLayout>

 

图片命名：