MainActivity.java
pacote com.zhang.showPhoto; importar android.app.ActionBar.LayoutParams;importar android.app.Activity;importar android.os.Bundle;importar android.view.View;importar android.view.View.OnClickListener;importar android.view.animation.AnimationUtils;importar android .widget.Button;importar android.widget.ImageSwitcher;importar android.widget.ImageView;importar android.widget.ViewSwitcher.ViewFactory; classe pública MainActivity estende atividade { private 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 }; índice interno privado = 0; imageSwitcher privado imageSwitcher; botão privado para cima, para baixo; @Override protegido void onCreate(Bundle saveInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); up=(Botão) findViewById(R.id.bt1); down=(Botão) 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 )); retornar imagemView; } }); imageSwitcher.setImageResource(imagId[índice]); 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]); } }); } }principal.xml
<?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" > <Botão 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" /> <Botão android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="下一张" android:id="@+id/bt2" /> </LinearLayout>
再来看一段代码
// Altera o valor BitmapFactory.Options opt = new BitmapFactory.Options(); opt.inJustDecodeBounds = verdadeiro; tente{bitmapIn = BitmapFactory.decodeFile(Puzzle.user.CUSTOM_IMAGE[customImage], opt); }catch(Exceção e){ if(D) Log.d(TAG,"erro"); retornar; } int in_w=opt.outWidth,in_h=opt.outHeight; // definindo o valor do imageview para o valor do imageview full_w = imageview.getWidth() full_h = getHeight() //计算缩放比例 带有四舍五入 int Size_rate=(in_w*in_h*10)/(full_w*full_h); if(Size_rate>10){Tamanho_taxa+=5; Taxa_tamanho/=10; }else{Tamanho_taxa=1; } // 重新设置opt 读取图片文件 opt.inSampleSize=Size_rate; opt.inJustDecodeBounds = falso; opt.inScaled = falso; opt.outWidth=full_w; opt.outHeight=full_h; bitmapIn = BitmapFactory.decodeFile(Puzzle.user.CUSTOM_IMAGE[customImage], opt);}