Android的ImageSwitcher和TextSw-android学习之旅（三十四）

ImageSwitcher简介

ImageSwitcher继承了ViewSwitcher，所以在切换时候会有动画，可以把它理解成一个动画版本的ImageView。
他的showNext（），和showPrevious（）方法分别显示下一个和上一个。
为ImageSwitcher提供一个ViewFactory，该ViewFactory的makeView（）生成的View必须是ImageView。
ImageSwicher可以用setimageResource（）和色图ImageDrawable（）以及setImageUri（）来设置图片资源。

支持动画的图片的浏览器代码示例

package peng.liu.test;

import android.app.Activity;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.FrameLayout;
import android.widget.GridView;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.ViewSwitcher;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


public class MainActivity extends Activity {
    private int[] imageIds = new int[]{
            R.drawable.ic_launcher,R.drawable.ic_launcher,R.drawable.ic_launcher,R.drawable.ic_launcher,R.drawable.ic_launcher,
            R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher
            };
    ImageSwitcher imageSwitcher;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        imageSwitcher = (ImageSwitcher) findViewById(R.id.imageSwitcher);
        List<Map<String,Object>> listItems = new ArrayList<Map<String,Object>>();
        for (int i = 0;i<imageIds.length;i++){
            Map<String,Object> item = new HashMap<String, Object>();
            item.put("image",imageIds[i]);
            listItems.add(item);
        }
        SimpleAdapter adapter = new SimpleAdapter(MainActivity.this,listItems,R.layout.cell,new String[]{"image"},new int[]{R.id.image02});
        imageSwitcher.setFactory(new ViewSwitcher.ViewFactory() {
            @Override
            public View makeView() {
                ImageView image = new ImageView(MainActivity.this);
                image.setScaleType(ImageView.ScaleType.FIT_CENTER);
                image.setLayoutParams(new ImageSwitcher.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,ViewGroup.LayoutParams.WRAP_CONTENT));
                return image;
            }
        });
        GridView grid = (GridView) findViewById(R.id.grid);
        grid.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                imageSwitcher.setImageResource(imageIds[i]);
            }
        });
        grid.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
                imageSwitcher.setImageResource(imageIds[i]);
            }

            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {

            }
        });
    };
}

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
        android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
        android:paddingRight="@dimen/activity_horizontal_margin"
        android:paddingTop="@dimen/activity_vertical_margin"
        android:paddingBottom="@dimen/activity_vertical_margin"
        tools:context=".MainActivity"
        >
        <GridView
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:horizontalSpacing="1pt"
            android:verticalSpacing="2pt"
            android:numColumns="4"
            android:gravity="center"
            android:id="@+id/grid"
            />
        <ImageSwitcher
            android:layout_width="300dp"
            android:layout_height="300dp"
            android:id="@+id/imageSwitcher"
            android:layout_gravity="center_horizontal"
            android:inAnimation="@android:anim/fade_in"
            android:outAnimation="@android:anim/fade_out"
            />
    </LinearLayout>

TextSwitcher简介

TextSwitcher也是继承于ViewSwitcher，不同设置饿ViewFactory的makeView（）返回的是TextView组件，可以像Button那样设置点击事件，在xml文件设置OnClick：

代码示例

package peng.liu.test;

import android.app.Activity;
import android.graphics.Color;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.FrameLayout;
import android.widget.GridView;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.SimpleAdapter;
import android.widget.TextSwitcher;
import android.widget.TextView;
import android.widget.ViewSwitcher;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


public class MainActivity extends Activity {
    TextSwitcher textSwitcher;
    private String[] strs = new String[]{
            "java","python","xml","html"
    };
    int currentStr;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        textSwitcher = (TextSwitcher) findViewById(R.id.textSwitcher);
        textSwitcher.setFactory(new ViewSwitcher.ViewFactory() {
            @Override
            public View makeView() {
                TextView text = new TextView(MainActivity.this);
                text.setTextSize(40);
                text.setTextColor(Color.MAGENTA);
                return text;
            }
        });
        next(null);
    }
    public void next(View view){
        textSwitcher.setText(strs[currentStr++%strs.length]);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
        android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
        android:paddingRight="@dimen/activity_horizontal_margin"
        android:paddingTop="@dimen/activity_vertical_margin"
        android:paddingBottom="@dimen/activity_vertical_margin"
        tools:context=".MainActivity"
    android:orientation="vertical"
        >
        <TextSwitcher
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:inAnimation="@anim/slide_in"
            android:outAnimation="@anim/slide_out"
            android:onClick="next"
            android:id="@+id/textSwitcher"/>
    </LinearLayout>