android——拍照，相册图片剪切其实就这么简单

接触android这么久了。还没有真正的浩浩看看android拍照，相册图片剪切到底是怎么回事，每次都是从别人的代码一扣，就过来了。其实，谷歌提供的API已经很强大。只需要用的好，就那么几句就可以搞定神秘的拍照和剪切图片。废话不多少，直接看源码

package com.example.testcamera;

import java.io.FileNotFoundException;

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

public class MainActivity extends Activity implements OnClickListener {
    private Button btnc, btnp;
    private ImageView img;
    private Intent intent;
    private final int dataFromCamera = 1;
    private final int dataFromAlbum = 2;
    private final int cropFromCamera = 3;
    private final int cropFromAlbum = 4;
    private Uri mUri = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }

    private void initView() {
        btnc = (Button) findViewById(R.id.btnc);
        btnp = (Button) findViewById(R.id.btnp);
        img = (ImageView) findViewById(R.id.img);
        btnc.setOnClickListener(this);
        btnp.setOnClickListener(this);

    }

    @Override
    public void onClick(View v) {
        int id = v.getId();
        switch (id) {
        case R.id.btnc:
            openCamera();
            break;
        case R.id.btnp:
            openPhoto();
            break;
        default:
            break;
        }

    }

    private void openCamera() {
        intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        startActivityForResult(intent, dataFromCamera);
    }

    private void openPhoto() {
        intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.setType("image/*");
        startActivityForResult(intent, dataFromAlbum);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode == RESULT_OK) {
            Uri uri = null;
            if (data.getData() != null) {
                uri = data.getData();
                mUri = uri;
            }
            switch (requestCode) {
            case dataFromCamera:
                cropImageUri(uri, 800, 600, cropFromCamera);
                break;
            case dataFromAlbum:
                cropImageUri(uri, 800, 600, cropFromAlbum);
                break;
            case cropFromCamera:
                if (mUri != null) {
                    Bitmap bitmap = decodeUriAsBitmap(mUri);
                    img.setImageBitmap(bitmap);
                }
                break;
            case cropFromAlbum:
                if (mUri != null) {
                    Bitmap bitmap = decodeUriAsBitmap(mUri);
                    img.setImageBitmap(bitmap);
                }
                break;
            default:
                break;

            }
        }

    }

    private void cropImageUri(Uri uri, int outputX, int outputY, int requestCode) {

        Intent intent = new Intent("com.android.camera.action.CROP");

        intent.setDataAndType(uri, "image/*");

        intent.putExtra("crop", "true");

        intent.putExtra("aspectX", 4);

        intent.putExtra("aspectY", 3);

        intent.putExtra("outputX", outputX);

        intent.putExtra("outputY", outputY);

        intent.putExtra("scale", true);

        intent.putExtra(MediaStore.EXTRA_OUTPUT, uri);

        intent.putExtra("return-data", false);

        intent.putExtra("outputFormat", Bitmap.CompressFormat.JPEG.toString());

        intent.putExtra("noFaceDetection", true); // no face detection

        startActivityForResult(intent, requestCode);

    }

    private Bitmap decodeUriAsBitmap(Uri uri) {
        Bitmap bitmap = null;
        try {
            bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(uri));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            return null;
        }
        return bitmap;
    }

}

xml布局文件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <Button
        android:id="@+id/btnc"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@android:color/holo_purple"
        android:text="拍照"
        android:textColor="@android:color/white" />

    <Button
        android:id="@+id/btnp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@android:color/holo_orange_dark"
        android:text="从相册中选取"
        android:textColor="@android:color/white" />

    <ImageView
        android:id="@+id/img"
        android:layout_width="300dp"
        android:layout_height="300dp"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="50dp" />

</LinearLayout>

mainfest.xml文件

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.testcamera"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="16"
        android:targetSdkVersion="18" />

    <uses-permission android:name="android.permission.CAMERA" />
    <uses-feature android:name="android.hardware.camera" />
    <uses-feature android:name="android.hardware.camera.autofocus" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

注意要配置权限呀。