项目中使用的---使用系统照相机拍照预览上传

布局文件:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" android:gravity="center_horizontal">

<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="使用系统照相机拍照" android:onClick="click"/>

<ImageView
android:id="@+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />

</LinearLayout>

代码:

package uk.ac.essex.camerademo1;

import java.io.File;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.BitmapFactory.Options;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.view.Display;
import android.view.View;
import android.widget.ImageView;

public class Camerademo1Activity extends Activity {
private static final int CAPTURE_PIC = 0;

private ImageView imageView;

private int width;
private int height;
private String imageFilePath;
private Uri imageFileUri;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
imageView = (ImageView) findViewById(R.id.imageView);
init();
}

private void init() {
Display display = getWindowManager().getDefaultDisplay();
width = display.getWidth();
height = display.getHeight();

imageFilePath = Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED) ? Environment.getExternalStorageDirectory() + "/1.jpg" : null;
imageFileUri = Uri.fromFile(new File(imageFilePath));
}

public void click(View view) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);//相机捕捉图片的意图
intent.putExtra(MediaStore.EXTRA_OUTPUT, imageFileUri);//指定系统相机拍照保存在imageFileUri所指的位置
startActivityForResult(intent, CAPTURE_PIC);//启动系统相机,等待返回
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK && requestCode == CAPTURE_PIC) {
Options options = new Options();
options.inJustDecodeBounds = true;//设置解码只是为了获取图片的width和height值,而不是真正获取图片
Bitmap bitmap = BitmapFactory.decodeFile(imageFilePath, options);//解码后可以options.outWidth和options.outHeight来获取图片的尺寸

int widthRatio = (int) Math.ceil(options.outWidth / width);//获取宽度的压缩比率
int heightRatio = (int) Math.ceil(options.outHeight / height);//获取高度的压缩比率

if (widthRatio > 1 || heightRatio > 1) {//只要其中一个的比率大于1,说明需要压缩
if(widthRatio>=heightRatio){//取options.inSampleSize为宽高比率中的最大值
options.inSampleSize = widthRatio;
}else{
options.inSampleSize = heightRatio;
}
}

options.inJustDecodeBounds = false;//设置为真正的解码图片
bitmap = BitmapFactory.decodeFile(imageFilePath, options);//解码图片

imageView.setImageBitmap(bitmap);
}
super.onActivityResult(requestCode, resultCode, data);
}

}