imageview android 读取图像,Android手机开发：ImageView使用和从内存读取图片显示

import java.io.File;

import android.app.Activity;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.ImageView;

import android.widget.TextView;

public class ImageViewActivity extends Activity {

private Button myButtonSwitchImg;

private ImageView myImageView;

private TextView myTextView;

private String filename = "/data/data/img.bmp";

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setTitle("ImageView");

setContentView(R.layout.imageview);

myButtonSwitchImg = (Button) findViewById(R.id.imgButton);

myImageView = (ImageView) findViewById(R.id.imageView);

myTextView = (TextView) findViewById(R.id.imgText);

myButtonSwitchImg.setOnClickListener(new Button.OnClickListener() {

@Override

public void onClick(View v) {

File file = new File(filename);

if(file.exists()) {

Bitmap bm = BitmapFactory.decodeFile(filename);

myImageView.setImageBitmap(bm);

myTextView.setText(filename);

} else {

myTextView.setText("File Not Found!");

}

}

});

}

}

对应的XML文件如下：

android:orientation="vertical" android:layout_width="fill_parent"

android:layout_height="wrap_content">

android:id="@+id/imgText"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="图片展示:" />

android:id="@+id/imageView"

android:src="@drawable/imgqr"

android:layout_width="fill_parent"

android:layout_height="wrap_content"/>

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Switch"

android:id="@+id/imgButton"

android:layout_gravity="center_horizontal">