如何在安卓中从相机和图库裁剪图像？
在上一篇文章中，我们已经讨论了如何在安卓 中从图库中选择图像，但是在这个项目中没有裁剪 功能 。有时候我们在手机上拍照，想更新为个人资料图片。但我们需要移除背景。因此，在这种情况下，我们可以使用裁剪图像功能来移除背景，然后上传图像。下面给出一个视频示例，来了解一下我们在本文中要做什么。注意，我们将使用 Java 语言来实现这个项目。
[https://media.geeksforgeeks.org/wp-content/uploads/20210217161357/whatsapp-video-2021-02-17-at-40535-pm_mvPlAfg2.mp4](https://media.geeksforgeeks.org/wp-content/uploads/20210217161357/whatsapp-video-2021-02-17-at-40535-pm_mvPlAfg2.mp4)分步实施
第一步:创建新项目
要在安卓工作室创建新项目，请参考如何在安卓工作室创建/启动新项目。注意选择 Java 作为编程语言。
步骤 2: 将依赖项添加到 build.gradle(模块:app)文件
导航到渐变脚本>构建.渐变(模块:应用)，并在依赖项部分添加以下依赖项。
//该库用于裁剪图像特征
API com . theartofdev . edmodo:Android-image-cropper:2.8 版。+"
//该库用于加载
//将图像裁剪到 ImageView 中。
实现' com . squareup . Picasso:Picasso:2 . 5 . 2 '
第 3 步:使用 AndroidManifest.xml 文件
将以下权限添加到 AndroidManifest.xml 文件中。
在 <应用> 标签内添加以下行。
Android:name = " com . artertofdev . edmodo . cropper . cropimageActivity "
安卓:主题="@style/Base。主题. AppCompat" />
下面是完整的 AndroidManifest.xml 文件的代码。
可扩展标记语言
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.anni.cropimage">
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.CAMERA" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.theartofdev.edmodo.cropper.CropImageActivity"
android:theme="@style/Base.Theme.AppCompat" />
</application>
</manifest>
步骤 3:使用 activity_main.xml 文件
导航到应用程序> res >布局> activity_main.xml 并将下面的代码添加到该文件中。下面是 activity_main.xml 文件的代码。
可扩展标记语言
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="100dp"
android:gravity="center"
android:orientation="vertical"
tools:context=".MainActivity">
<!--Here the selected cropped image will be shown-->
<ImageView
android:id="@+id/set_profile_image"
android:layout_width="300dp"
android:layout_height="300dp"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="40dp"
android:src="@drawable/ic_image_black_24dp" />
<!--Here we are clicking on this text to select
an image from camera or gallery-->
<TextView
android:id="@+id/click"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Click Here to select an Image"
android:textSize="22sp"
android:textStyle="bold" />
</LinearLayout>
第四步:使用MainActivity.java 文件
转到MainActivity.java文件，参考以下代码。以下是MainActivity.java文件的代码。代码中添加了注释，以更详细地理解代码。
Java 语言(一种计算机语言，尤用于创建网站)
import android.Manifest;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.content.ContextCompat;
import com.squareup.picasso.Picasso;
import com.theartofdev.edmodo.cropper.CropImage;
public class MainActivity extends AppCompatActivity {
ImageView userpic;
private static final int GalleryPick = 1;
private static final int CAMERA_REQUEST = 100;
private static final int STORAGE_REQUEST = 200;
private static final int IMAGEPICK_GALLERY_REQUEST = 300;
private static final int IMAGE_PICKCAMERA_REQUEST = 400;
String cameraPermission[];
String storagePermission[];
Uri imageuri;
TextView click;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Here we are initialising
// the text and image View
click = findViewById(R.id.click);
userpic = findViewById(R.id.set_profile_image);
// allowing permissions of gallery and camera
cameraPermission = new String[]{Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE};
storagePermission = new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE};
// After clicking on text we will have
// to choose whether to
// select image from camera and gallery
click.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
showImagePicDialog();
}
});
}
private void showImagePicDialog() {
String options[] = {"Camera", "Gallery"};
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Pick Image From");
builder.setItems(options, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
if (which == 0) {
if (!checkCameraPermission()) {
requestCameraPermission();
} else {
pickFromGallery();
}
} else if (which == 1) {
if (!checkStoragePermission()) {
requestStoragePermission();
} else {
pickFromGallery();
}
}
}
});
builder.create().show();
}
// checking storage permissions
private Boolean checkStoragePermission() {
boolean result = ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == (PackageManager.PERMISSION_GRANTED);
return result;
}
// Requesting gallery permission
private void requestStoragePermission() {
requestPermissions(storagePermission, STORAGE_REQUEST);
}
// checking camera permissions
private Boolean checkCameraPermission() {
boolean result = ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) == (PackageManager.PERMISSION_GRANTED);
boolean result1 = ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == (PackageManager.PERMISSION_GRANTED);
return result && result1;
}
// Requesting camera permission
private void requestCameraPermission() {
requestPermissions(cameraPermission, CAMERA_REQUEST);
}
// Requesting camera and gallery
// permission if not given
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
switch (requestCode) {
case CAMERA_REQUEST: {
if (grantResults.length > 0) {
boolean camera_accepted = grantResults[0] == PackageManager.PERMISSION_GRANTED;
boolean writeStorageaccepted = grantResults[1] == PackageManager.PERMISSION_GRANTED;
if (camera_accepted && writeStorageaccepted) {
pickFromGallery();
} else {
Toast.makeText(this, "Please Enable Camera and Storage Permissions", Toast.LENGTH_LONG).show();
}
}
}
break;
case STORAGE_REQUEST: {
if (grantResults.length > 0) {
boolean writeStorageaccepted = grantResults[0] == PackageManager.PERMISSION_GRANTED;
if (writeStorageaccepted) {
pickFromGallery();
} else {
Toast.makeText(this, "Please Enable Storage Permissions", Toast.LENGTH_LONG).show();
}
}
}
break;
}
}
// Here we will pick image from gallery or camera
private void pickFromGallery() {
CropImage.activity().start(MainActivity.this);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == CropImage.CROP_IMAGE_ACTIVITY_REQUEST_CODE) {
CropImage.ActivityResult result = CropImage.getActivityResult(data);
if (resultCode == RESULT_OK) {
Uri resultUri = result.getUri();
Picasso.with(this).load(resultUri).into(userpic);
}
}
}
}
输出:
[https://media.geeksforgeeks.org/wp-content/uploads/20210217161357/whatsapp-video-2021-02-17-at-40535-pm_mvPlAfg2.mp4](https://media.geeksforgeeks.org/wp-content/uploads/20210217161357/whatsapp-video-2021-02-17-at-40535-pm_mvPlAfg2.mp4)github link:https://github . com/anni 1123/cropiment
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