Android中截圖功能

在實際應用中，經常需要對圖片進行處理，包括壓縮、截圖等等，其實android系統提供了一個可以截圖的activity，我們只需調用它就行了，下面示例完成一個通過相機照相或相冊選取圖片后對其截圖的功能，其實知道圖片的路勁都可以調用截圖activity，代碼如下：

測試activity：

package com.home.testclipimage;

import java.io.File;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.provider.MediaStore.Images.Media;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

public class TestClipImageActivity extends Activity implements OnClickListener {
    private Button gallaryBtn;
    private Button cameraBtn;
    private ImageView showImage;
    private File file;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        gallaryBtn = (Button) findViewById(R.id.main_btn_gallery);
        cameraBtn = (Button) findViewById(R.id.main_btn_camera);
        gallaryBtn.setOnClickListener(this);
        cameraBtn.setOnClickListener(this);
        showImage = (ImageView) findViewById(R.id.main_image);
    }

    @Override
    public void onClick(View v) {
        if (v == gallaryBtn) {
            // 跳轉至相冊界面
            Intent intent = new Intent(Intent.ACTION_PICK,
                    Media.EXTERNAL_CONTENT_URI);
            startActivityForResult(intent, 0);
        }
        if (v == cameraBtn) {
            if (!Environment.MEDIA_MOUNTED.equals(Environment
                    .getExternalStorageState())) {
                Toast.makeText(this, "請插入SD卡", Toast.LENGTH_SHORT).show();
                return;
            }
            // 跳轉至相機界面
            Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            file = new File(Environment.getExternalStorageDirectory(),
                    getPhotoName());
            // 指定相機拍照后相片的存儲位置
            intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(file));
            startActivityForResult(intent, 1);
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        // 系統相冊返回
        if (requestCode == 0 && resultCode == Activity.RESULT_OK
                && data != null) {
            startPhotoZoom(data.getData(), 150);// 截圖
        }
        // 系統相機返回
        if (requestCode == 1 && resultCode == Activity.RESULT_OK) {
            startPhotoZoom(Uri.fromFile(file), 150);// 截圖
        }
        // 截圖后返回
        if (requestCode == 2 && data != null) {
            Bundle bundle = data.getExtras();
            if (bundle != null) {
                Bitmap bitmap = bundle.getParcelable("data");
                showImage.setBackgroundDrawable(new BitmapDrawable(bitmap));
            }
        }
    }

    /**
     * 跳轉至系統截圖界面進行截圖
     * 
     * @param data
     * @param size
     */
    private void startPhotoZoom(Uri data, int size) {
        Intent intent = new Intent("com.android.camera.action.CROP");
        intent.setDataAndType(data, "image/*");
        // crop為true時表示顯示的view可以剪裁
        intent.putExtra("crop", "true");
        // aspectX aspectY 是寬高的比例
        intent.putExtra("aspectX", 1);
        intent.putExtra("aspectY", 1);
        // outputX,outputY 是剪裁圖片的寬高
        intent.putExtra("outputX", size);
        intent.putExtra("outputY", size);
        intent.putExtra("return-data", true);
        startActivityForResult(intent, 2);
    }

    /**
     * 產生照片名稱
     * 
     * @return
     */
    private String getPhotoName() {
        String name = System.currentTimeMillis() + ".jpg";
        return name;
    }
}

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

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/main_btn_gallery"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="相冊" />

        <Button
            android:id="@+id/main_btn_camera"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="相機" />
    </LinearLayout>

    <ImageView
        android:id="@+id/main_image"
        android:layout_width="150dp"
        android:layout_height="150dp"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="30dp" />

</LinearLayout>

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>