本程序包含一个按钮Button 和一个图片视图ImageView
xml文件:
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
android:id="@+id/p_w_picpath"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="显示图片" />
代码:
package com.wsl.bitmaptest;
import java.io.InputStream;
import android.os.Bundle;
import android.app.Activity;
import android.content.res.AssetManager;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
public class MainActivity extends Activity {
String[] p_w_picpaths = null;
AssetManager assetManager = null;
int currentImage = 0;
ImageView p_w_picpathView;
Button button;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
p_w_picpathView = (ImageView) this.findViewById(R.id.p_w_picpath);
try {
assetManager = getAssets();
//获取目录下所有文件
p_w_picpaths = assetManager.list("");
} catch (Exception e) {
e.printStackTrace();
}
button = (Button) this.findViewById(R.id.button);
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
if (currentImage >= p_w_picpaths.length) {
currentImage = 0;
}
while (!p_w_picpaths[currentImage].endsWith(".png")
&& !p_w_picpaths[currentImage].endsWith(".jpg")
&& !p_w_picpaths[currentImage].endsWith(".gif")) {
currentImage++;
if (currentImage >= p_w_picpaths.length) {
currentImage = 0;
}
}
InputStream assetFile = null;
try {
assetFile = assetManager.open(p_w_picpaths[currentImage++]);
} catch (Exception e) {
e.printStackTrace();
}
BitmapDrawable bitmapDrawable = (BitmapDrawable) p_w_picpathView
.getDrawable();
if (bitmapDrawable != null
&& !bitmapDrawable.getBitmap().isRecycled()) {
bitmapDrawable.getBitmap().recycle();
}
p_w_picpathView.setImageBitmap(BitmapFactory.decodeStream(assetFile));
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}