簡述：

  Android開發中會經常遇到呼叫系統相機功能的場景，今天總結一下Camera的基本使用。

技術點：

    1、首先要考慮許可權問題，Android6.0以上的系統需要動態申請許可權，實現方式如下：

    /**
     * 方法描述：針對Android 6.0以上系統的動態許可權申請
     */
    private void requestCameraPermission() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            requestPermissions(new String[]{Manifest.permission.CAMERA}, MY_PERMISSIONS_REQUEST_CODE);
            return;
        }

        launchCamera();
    }
 

    2、其次通過重寫onRequestPermissionsResult（）方法處理許可權申請結果。

    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (MY_PERMISSIONS_REQUEST_CODE == requestCode) {
            //迴圈遍歷已經申請到的許可權
            for (int index = 0; index < permissions.length; index++) {
                switch (permissions[index]) {
                    case Manifest.permission.CAMERA:
                        //使用者授權
                        if (PackageManager.PERMISSION_GRANTED == grantResults[index]) {
                            launchCamera();
                        } else if (PackageManager.PERMISSION_DENIED == grantResults[index]) {
                            Toast.makeText(CameraActivity.this, "應用沒有拍照許可權，請授權！", Toast.LENGTH_SHORT).show();
                        } else {
                            Toast.makeText(CameraActivity.this, "應用沒有拍照許可權，請授權", Toast.LENGTH_SHORT).show();
                        }
                        break;
                }

            }

        }
    }
 

3、其次是系統相機的呼叫及其拍照結果的回撥。

    /**
     * 方法描述：啟動系統相機
     */
    private void launchCamera() {
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        startActivityForResult(intent, REQUEST_CODE);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode == Activity.RESULT_OK) {
            Intent intent = new Intent(CameraActivity.this, PhotoShowActivity.class);
            intent.putExtra("picture", data.getExtras());
            startActivity(intent);
        } else {
            launchCamera();
        }
    }
 

程式碼實現：

 CameraActivity程式碼：

package com.lizhenya.systemcamera;

import android.Manifest;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.Window;
import android.widget.Toast;

public class CameraActivity extends Activity {
    private static final int REQUEST_CODE = 1;
    private static final int MY_PERMISSIONS_REQUEST_CODE = 2;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);

        requestCameraPermission();
    }


    /**
     * 方法描述：啟動系統相機
     */
    private void launchCamera() {
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        startActivityForResult(intent, REQUEST_CODE);
    }

    /**
     * 方法描述：針對Android 6.0以上系統的動態許可權申請
     */
    private void requestCameraPermission() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            requestPermissions(new String[]{Manifest.permission.CAMERA}, MY_PERMISSIONS_REQUEST_CODE);
            return;
        }

        launchCamera();
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode == Activity.RESULT_OK) {
            Intent intent = new Intent(CameraActivity.this, PhotoShowActivity.class);
            intent.putExtra("picture", data.getExtras());
            startActivity(intent);
        } else {
            launchCamera();
        }
    }


    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (MY_PERMISSIONS_REQUEST_CODE == requestCode) {
            //迴圈遍歷已經申請到的許可權
            for (int index = 0; index < permissions.length; index++) {
                switch (permissions[index]) {
                    case Manifest.permission.CAMERA:
                        if (PackageManager.PERMISSION_GRANTED == grantResults[index]) {
                            launchCamera();
                        } else if (PackageManager.PERMISSION_DENIED == grantResults[index]) {
                            Toast.makeText(CameraActivity.this, "應用沒有拍照許可權，請授權！", Toast.LENGTH_SHORT).show();
                        } else {
                            Toast.makeText(CameraActivity.this, "應用沒有拍照許可權，請授權", Toast.LENGTH_SHORT).show();
                        }
                        break;
                }

            }

        }
    }
}

/**
 * 類描述：
 * Created by lizhenya on 16/8/23.
 */
public class PhotoShowActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);

        final Intent intent = getIntent();
        final Bundle bundle = intent.getBundleExtra("picture");
        Bitmap bitmap = (Bitmap) bundle.get("data");// 獲取相機返回的資料，並轉換為Bitmap圖片格式
        ((ImageView)findViewById(R.id.iv)).setImageBitmap(bitmap);
    }
}