MainActivity.java
包com.zhang.showPhoto；导入 android.app.ActionBar.LayoutParams;导入 android.app.Activity;导入 android.os.Bundle;导入 android.view.View;导入 android.view.View.OnClickListener;导入 android.view.animation.AnimationUtils;导入 android .widget.Button;导入android.widget.ImageSwitcher;导入android.widget.ImageView;导入android.widget.ViewSwitcher.ViewFactory;公共类 MainActivity 扩展 Activity { 私有 int[] imagId=new int[]{ R.drawable.img01,R.drawable.img02,R.drawable.img03,R.drawable.img04, R.drawable.img05,R.drawable .img06,R.drawable.img07,R.drawable.img08, R.drawable.img09,R.drawable.img10 };私有整数索引=0；私有图像切换器图像切换器；私有按钮向上、向下； @Override protected void onCreate(Bundle savingInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main);向上=(按钮) findViewById(R.id.bt1);向下=(按钮)findViewById(R.id.bt2); imageSwitcher =（ImageSwitcher）findViewById（R.id.imagSw1）; imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in)); imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out)); imageSwitcher.setFactory(new ViewFactory() { public View makeView() { ImageView imageView = new ImageView(MainActivity.this); imageView.setScaleType(ImageView.ScaleType.FIT_CENTER); imageView.setLayoutParams(new ImageSwitcher.LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT )); 返回 imageView } }); imageSwitcher.setImageResource(imagId[索引]); up.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { if(index>0){ index--; }else{ index=imagId.length-1; } imageSwitcher.setImageResource(imagId[index] ); down.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { if(index<imagId.length-1){ index++; }else{ index=0; } imageSwitcher.setImageResource(imagId[index]); } }); } }主文件
<?xml version="1.0"encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:background="@drawable/bg1" android:id="@+id/llayout" android:layout_width="fill_parent" android:layout_height="fill_parent" android:gravity="center" android:orientation="horizontal" > <按钮android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="上一张" android:id="@+id/bt1" /> <ImageSwitcher android:layout_width="wrap_content" android:layout_height=" wrap_content" android:id="@+id/imagSw1" android:layout_gravity="center" /> <按钮 android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="下一张" android:id="@+id/bt2" /> </LinearLayout>
再看一段代码
// 获取图片的宽高 BitmapFactory.Options opt = new BitmapFactory.Options(); opt.inJustDecodeBounds = true;尝试{ bitmapIn = BitmapFactory.decodeFile(Puzzle.user.CUSTOM_IMAGE[customImage], opt); }catch(异常e){ if(D) Log.d(TAG,"错误");返回; int in_w=opt.outWidth,in_h=opt.outHeight; // 获取imageview的尺寸注意imageview的宽高比要与原图相同，否则需要另外计算 full_w = imageview.getWidth() full_h = getHeight() // 计算缩放比例 四配舍五入 int Size_rate=(in_w*in_h*10 )/(full_w*full_h);如果(Size_rate>10){ Size_rate+=5; size_rate/=10； }其他{ Size_rate=1; } // 重新设置opt读取图片文件 opt.inSampleSize=Size_rate; opt.inJustDecodeBounds = false; opt.inScaled = false; opt.outWidth=full_w; opt.outHeight=full_h; bitmapIn = BitmapFactory.decodeFile(Puzzle.user.CUSTOM_IMAGE[customImage], opt);}