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法律研究如何在安卓应用程序中调整图像大小？
此示例演示如何在 Android 应用程序中调整图像大小。
步骤 1 − 在 Android Studio 中创建新项目，转到“文件 ⇒ 新项目”，并填写所有必需的详细信息以创建新项目。
步骤 2 − 将以下代码添加到 res/layout/activity_main.xml。
<? xml version= "1.0" encoding= "utf-8" ?> <RelativeLayout 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 :gravity= "center" tools :context= ".MainActivity" > <ImageView android :id= "@+id/ivImage" android :layout_width= "wrap_content" android :layout_height= "wrap_content" android :layout_centerHorizontal= "true" android :contentDescription= "@string/app_name" android :src= "@drawable/ic_launcher_foreground" /> <LinearLayout android :layout_width= "match_parent" android :layout_height= "wrap_content" android :layout_below= "@+id/ivImage" android :layout_centerHorizontal= "true" > <Button android :layout_width= "0dp" android :layout_height= "wrap_content" android :layout_marginTop= "8dp" android :layout_weight= "1" android :onClick= "uploadImage" android :text= "Upload Image" /> <Button android :layout_width= "0dp" android :layout_height= "wrap_content" android :layout_marginTop= "8dp" android :layout_weight= "1" android :onClick= "resizeImage" android :text= "Resize Image" /> </LinearLayout> </RelativeLayout>
步骤 3 − 将以下代码添加到 src/MainActivity.java
package app.tutorialspoint.com.sample ;
import android.app.Activity ;
import android.content.Intent ;
import android.graphics.Bitmap ;
import android.net.Uri ;
import android.provider.MediaStore ;
import android.support.v7.app.AppCompatActivity ;
import android.os.Bundle ;
import android.view.View ;
import android.widget.ImageView ;
import java.io.IOException ;
public class MainActivity extends AppCompatActivity {
ImageView ivImage ;
public static final int PICK_IMAGE = 1 ;
Bitmap yourBitmap ;
@Override
protected void onCreate (Bundle savedInstanceState) {
super .onCreate(savedInstanceState) ;
setContentView(R.layout. activity_main ) ;
ivImage = findViewById(R.id. ivImage ) ;
}
public void uploadImage (View view) {
Intent intent = new Intent(Intent. ACTION_GET_CONTENT ) ;
intent.setType( "image/*" ) ;
startActivityForResult(intent , PICK_IMAGE ) ;
}
public void resizeImage (View view) {
Bitmap resized = Bitmap. createScaledBitmap ( yourBitmap , 400 , 400 , true ) ;
ivImage .setImageBitmap(resized) ;
}
@Override
public void onActivityResult ( int requestCode , int resultCode , Intent data) {
super .onActivityResult(requestCode , resultCode , data) ;
if (requestCode == PICK_IMAGE && resultCode == Activity. RESULT_OK ) {
if (data == null ) {
//Display an error
return;
}
try {
Uri imageUri = data.getData() ;
yourBitmap =
MediaStore.Images.Media. getBitmap ( this .getContentResolver() , imageUri) ;
ivImage .setImageBitmap( yourBitmap ) ;
} catch (IOException e) {
e.printStackTrace() ;
}
}
}
}步骤 4 − 将以下代码添加到 androidManifest.xml
<? xml version= "1.0" encoding= "utf-8" ?> <manifest xmlns: android = "http://schemas.android.com/apk/res/android" package= "app.tutorialspoint.com.sample" > <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> </application> </manifest>
更新于： 06-07-2020
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