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要点：
(查看Api总结)
1：ImageSwitcher 继承 ViewSwitcher， (ViewSwitcher 有继承FrameLayout ）
2： 要实现切图必须实现 ViewSwitcher.ViewFactory接口中的 makeView()
易错点：
1：
mImageSwitcher.setFactory(this);
mImageSwitcher.setImageResource(mImages[0]);
setImageResource必须调用在setFactory之后。 原因：根据源码分析调用setFactory获得接口，才能
获得makeView()返回的view 否则抛空指针异常
2： 在makeView中设置布局参数 要用FrameLayout布局参数
package com.imageswitcher;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AnimationUtils;
import android.widget.FrameLayout;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.Toast;
import android.widget.ViewSwitcher;
public class MainActivity extends Activity implements ViewSwitcher.ViewFactory {
private LinearLayout mLinearLayout;
private ImageSwitcher mImageSwitcher;
private Integer[] mImages = {R.drawable.android01, R.drawable.android02, R.drawable.android03, R.drawable.android04,
R.drawable.android05, R.drawable.android06, R.drawable.android07, R.drawable.android08, R.drawable.android09};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
mImageSwitcher.setFactory(this);
mImageSwitcher.setImageResource(mImages[0]);
mImageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));
mImageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));
for (int i = 0; i < mImages.length; i++) {
mLinearLayout.addView(getImageView(i));
}
}
private ImageView getImageView(final int i) {
ImageView imageView = new ImageView(this);
imageView.setImageResource(mImages[i]);
imageView.setId(i);
imageView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mImageSwitcher.setImageResource(mImages[i]);
Toast.makeText(v.getContext(), "选择了" + (v.getId() + 1) + "张图", Toast.LENGTH_SHORT).show();
}
});
return imageView;
}
private void initView() {
mLinearLayout = (LinearLayout) findViewById(R.id.linearLayout);
mImageSwitcher = (ImageSwitcher) findViewById(R.id.imageSwitcher);
}
@Override
public View makeView() {
ImageView imageView = new ImageView(this);
Log.i(MainActivity.class.getSimpleName(), "第几次调用");
imageView.setLayoutParams(new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT));
return imageView;
}
}
xml
<RelativeLayout 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" tools:context=".MainActivity"> <ImageSwitcher android:id="@+id/imageSwitcher" android:layout_width="match_parent" android:layout_height="200dp"> </ImageSwitcher> <HorizontalScrollView android:layout_below="@id/imageSwitcher" android:layout_width="match_parent" android:layout_height="100dp" > <LinearLayout android:id="@+id/linearLayout" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal"> </LinearLayout> </HorizontalScrollView> </RelativeLayout>
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原文地址：http://www.cnblogs.com/Free-Wind/p/4652706.html
