find image .java ------------android

最新推荐文章于 2022-06-15 10:32:21 发布

原创最新推荐文章于 2022-06-15 10:32:21 发布 · 1.9k 阅读

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文章标签：

#image #string #byte #file #null #import

本文介绍了一个Android应用如何通过用户选择的图片文件，使用Intent和ContentResolver进行读取，并通过Bitmap显示图片。包括从InputStream获取文件内容，转换为图片格式，以及展示图片到界面上的过程。

import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import android.app.Activity;
import android.content.ContentResolver;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.widget.ImageView;

public class FindImage extends Activity {
/** Called when the activity is first created. */

public static final String MIME_TYPE_IMAGE_JPEG = "image/jpeg";
public static final int ACTIVITY_GET_IMAGE = 2;
public static final String KEY_FILE_NAME = "name";
public static final String KEY_FILE_TYPE = "type";
public static final String KEY_FILE_BITS = "bits";
public static final String KEY_FILE_OVERWRITE = "overwrite";
public static final String KEY_FILE_URL = "url";
private byte[] mContent;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Intent getImage = new Intent(Intent.ACTION_GET_CONTENT);
getImage.addCategory(Intent.CATEGORY_OPENABLE);
getImage.setType(MIME_TYPE_IMAGE_JPEG);
startActivityForResult(getImage, ACTIVITY_GET_IMAGE);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// newImage(data.getData());

if (resultCode != RESULT_OK) {

return;

}

Bitmap bm = null;

ContentResolver resolver = getContentResolver();

if (requestCode == 2) {

try {

Uri originalUri = data.getData();
mContent = getBytesFromInputStream(resolver.openInputStream(Uri
.parse(originalUri.toString())), 3500000);

bm = getPicFromBytes(mContent, null);

ImageView iv = getThemedImageView();
iv.setImageBitmap(bm);
setContentView(iv);
} catch (IOException e) {
System.out.println(e.getMessage());
}

}

}

public static Bitmap getPicFromBytes(byte[] bytes,
BitmapFactory.Options opts) {

if (bytes != null)
if (opts != null)
return BitmapFactory.decodeByteArray(bytes, 0, bytes.length,
opts);
else
return BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
return null;
}

public static byte[] getBytesFromInputStream(InputStream is, int bufsiz)
throws IOException {
int total = 0;
byte[] bytes = new byte[4096];
ByteBuffer bb = ByteBuffer.allocate(bufsiz);

while (true) {
int read = is.read(bytes);
if (read == -1)
break;
bb.put(bytes, 0, read);
total += read;
}

byte[] content = new byte[total];
bb.flip();
bb.get(content, 0, total);

return content;
}

private ImageView getThemedImageView() {
ImageView iv = new ImageView(this);
iv.setBackgroundResource(android.R.drawable.gallery_thumb);
return iv;
}
}