调用系统图片裁剪限定尺寸

内容：手机系统的裁剪介绍

代码如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.example.leixiansheng.cutphoto.MainActivity">

    <Button
        android:id="@+id/btn_select_from_local"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="cut"/>

    <ImageView
        android:id="@+id/iv_local"
        android:layout_gravity="center_horizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

package com.example.leixiansheng.cutphoto;

import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.List;

import butterknife.BindView;
import butterknife.ButterKnife;
import butterknife.OnClick;

public class MainActivity extends AppCompatActivity {

	@BindView(R.id.btn_select_from_local)
	Button mBtnSelectFromLocal;
	@BindView(R.id.iv_local)
	ImageView mIvLocal;

	private static final String TAG = MainActivity.class.getSimpleName();
	private static final int CHOOSE_PICTURE = 1;
	private static final int CROP_PICTURE = 2;
	private static final int REQUEST_CODE_OK = 3;

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

	@OnClick(R.id.btn_select_from_local)
	public void onClick() {
		requestRunTimePermission(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE});
	}

	private void selectFromLocal() {
		Intent intent = new Intent(Intent.ACTION_PICK, null);
		intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/*");
		startActivityForResult(intent, CHOOSE_PICTURE);
	}

	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		super.onActivityResult(requestCode, resultCode, data);
		Log.d(TAG, resultCode + "");
		if (resultCode == RESULT_OK) {
			switch (requestCode) {
				case CHOOSE_PICTURE:
					startPhotoZoom(data.getData());
					break;
				case CROP_PICTURE: // 取得裁剪后的图片
					try {
						mIvLocal.setImageBitmap(BitmapFactory.decodeStream( getContentResolver().openInputStream(imageUri) ));
					} catch (FileNotFoundException e) {
						e.printStackTrace();
					}
					break;
				default:
					break;
			}
		}
	}

	private static final String IMAGE_FILE_LOCATION = "file:///" + Environment.getExternalStorageDirectory().getPath() + "/temp.jpg";
	private Uri imageUri = Uri.parse(IMAGE_FILE_LOCATION);

	public void startPhotoZoom(Uri uri) {
		Intent intent = new Intent("com.android.camera.action.CROP");
		intent.setDataAndType(uri, "image/*");
		// 下面这个crop=true是设置在开启的Intent中设置显示的VIEW可裁剪
		intent.putExtra("crop", "true");
		intent.putExtra("scale", true);

		intent.putExtra("aspectX", 2);
		intent.putExtra("aspectY", 1);

		intent.putExtra("outputX", 600);
		intent.putExtra("outputY", 300);

		intent.putExtra("return-data", false);
		intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
		intent.putExtra("outputFormat", Bitmap.CompressFormat.JPEG.toString());
		intent.putExtra("noFaceDetection", true); // no face detection

		startActivityForResult(intent, CROP_PICTURE);
	}

	/**
	 * 动态权限请求
	 * @param permissions
	 */
	public void requestRunTimePermission(String[] permissions) {
		List<String> permissionList = new ArrayList<>();
		for (String permission : permissions) {
			if (ContextCompat.checkSelfPermission(this, permission) != PackageManager.PERMISSION_GRANTED) {//检测当前权限是否已经被允许
				permissionList.add(permission);//没有则添加进集合
			}
		}
		if (!permissionList.isEmpty()) {//检测权限集合中是否有未申请的权限
			ActivityCompat.requestPermissions(this, permissionList.toArray(new String[permissionList.size()]), REQUEST_CODE_OK);
		} else {
			//所有权限都通过了
			selectFromLocal();
		}
	}

	@Override
	public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
		super.onRequestPermissionsResult(requestCode, permissions, grantResults);
		switch (requestCode) {
			case REQUEST_CODE_OK:
				if (grantResults.length > 0) {
					List<String> deniedPermission = new ArrayList<>();
					for (int i = 0; i < grantResults.length; i++) {
						int grantResult = grantResults[i];
						String permission = permissions[i];
						if (grantResult != PackageManager.PERMISSION_GRANTED) {
							deniedPermission.add(permission);
						}
					}

					if (!deniedPermission.isEmpty()) {
						Toast.makeText(this, "权限不足", Toast.LENGTH_SHORT).show();
					} else
						selectFromLocal();
				}
				break;
				default:
					break;
		}
	}
}