Android实战简易教程-第二十九枪（基于Face++实现年龄识别APP）

博观而约取，厚积而薄发。这篇文章主要讲述Android实战简易教程-第二十九枪（基于Face++实现年龄识别APP）相关的知识，希望能为你提供帮助。
我们通过Face++提供的api和服务实现HowOld App的开发。首先我们实现图片的选择功能。
1.main.xml:
【Android实战简易教程-第二十九枪（基于Face++实现年龄识别APP）】

< RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/container" android:layout_width="match_parent" android:layout_height="match_parent"> < Button android:id="@+id/btn_getImage" android:layout_height="wrap_content" android:layout_width="wrap_content" android:text="Get image" android:layout_alignParentBottom="true" android:layout_alignParentRight="true" android:layout_marginRight="10dp" /> < Button android:id="@+id/btn_detect" android:layout_height="wrap_content" android:layout_width="wrap_content" android:text="Detect" android:layout_alignParentBottom="true" android:layout_toLeftOf="@+id/btn_getImage" /> < TextView android:id="@+id/tv_tip" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_alignParentBottom="true" android:layout_marginRight="10dp" android:text="tip" android:paddingLeft="10dp" android:gravity="center" android:layout_alignTop="@+id/btn_detect"/> < ImageView android:layout_above="@+id/btn_detect" android:layout_alignParentLeft="true" android:layout_alignParentRight="true" android:layout_alignParentTop="true" android:layout_height="wrap_content" android:layout_width="wrap_content" android:src="https://www.songbingjia.com/android/@drawable/t4" android:id="@+id/iv_photo" /> < FrameLayout android:id="@+id/id_waitting" android:layout_height="match_parent" android:layout_width="match_parent" android:visibility="gone" android:clickable="true"> < ProgressBar android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_gravity="center" /> < /FrameLayout> < /RelativeLayout>

2.MainActivity.java:

package com.yayun.howold; import android.content.Intent; import android.database.Cursor; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.net.Uri; import android.os.Bundle; import android.provider.MediaStore; import android.support.v7.app.ActionBarActivity; import android.view.View; import android.widget.Button; import android.widget.ImageView; import android.widget.TextView; public class MainActivity extends ActionBarActivity implements View.OnClickListener { private static final int PICK_CODE = 0x110; //随便设置一个常量 private ImageView mPhoto; private Button mGetImage, mDetect; private TextView mTip; private View mWaitting; private String mCurrentPhotoStr; private Bitmap mPhotoImg; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initViews(); //初始化控件 initEvents(); //点击事件}private void initEvents() { mGetImage.setOnClickListener(this); mDetect.setOnClickListener(this); }private void initViews() { mPhoto = (ImageView) findViewById(R.id.iv_photo); mGetImage = (Button) findViewById(R.id.btn_getImage); mDetect = (Button) findViewById(R.id.btn_detect); mTip = (TextView) findViewById(R.id.tv_tip); mWaitting = (View) findViewById(R.id.id_waitting); }@Override protected void onActivityResult(int requestCode, int resultCode, Intent intent) {//返回结果推断 if (requestCode == PICK_CODE) { if (intent != null) { Uri uri = intent.getData(); //获取uri //以下是为了获取图片的路径 Cursor cursor = getContentResolver().query(uri, null, null, null, null); cursor.moveToFirst(); int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA); //获取索引 mCurrentPhotoStr = cursor.getString(idx); //拿到图片的路径。当然我曾经的文章也有介绍怎么由uri获取string型的地址resizePhoto(); //压缩图片 mPhoto.setImageBitmap(mPhotoImg); //设置压缩后图片 mTip.setText("Click Detect==> "); } } super.onActivityResult(requestCode, resultCode, intent); }/** * 压缩图片 */ private void resizePhoto() { BitmapFactory.Options options = new BitmapFactory.Options(); options.inJustDecodeBounds = true; //不会载入图片，仅仅会获取图片的宽高 BitmapFactory.decodeFile(mCurrentPhotoStr, options); //options里已存取宽高double ratio = Math.max(options.outWidth * 1.0d / 1024f, options.outHeight * 1.0d / 1024f); //宽高尽可能小于1024，终于每一个图片不能超过3M options.inSampleSize = (int) Math.ceil(ratio); options.inJustDecodeBounds = false; //否则不会载入图片mPhotoImg = BitmapFactory.decodeFile(mCurrentPhotoStr, options); //压缩后的BitMap}@Override public void onClick(View view) { switch (view.getId()) { case R.id.btn_getImage: Intent intent = new Intent(Intent.ACTION_PICK); //选择 intent.setType("image/*"); //图片格式 startActivityForResult(intent, PICK_CODE); break; case R.id.btn_detect: break; }} }

执行实例：