我正在创建一个Android应用程序，我可以添加一个图像。但是，我想要做的是缩小图像以适合ImageButton大小。有没有办法做到这一点？
到目前为止我写的代码：
package awad865.project.ContactManager1;
import java.io.FileNotFoundException;
import java.io.InputStream;
import android.app.Activity;
import android.content.Intent;
import android.database.SQLException;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.NavUtils;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.Spinner;
public class AddContact extends Activity {
//declare private fields
private EditText firstName;
private EditText lastName;
private EditText number;
private EditText address;
private EditText date;
private EditText email;
private Spinner numberSpinner;
private Spinner emailSpinner;
private Spinner addressSpinner;
private Spinner dateSpinner;
private DatabaseHandler databaseHandler;
private ImageButton addPic;
private final int IMAGE_SELECTION =1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_contact);
//code that enables the title on the action bar
getActionBar().setDisplayShowTitleEnabled(true);
getActionBar().setDisplayHomeAsUpEnabled(true);
databaseHandler = new DatabaseHandler(this);
//intialise private fields
firstName = (EditText)findViewById(R.id.edit_first_name);
lastName = (EditText)findViewById(R.id.edit_last_name);
number = (EditText)findViewById(R.id.edit_number);
address = (EditText)findViewById(R.id.edit_address);
date = (EditText)findViewById(R.id.edit_date);
email =(EditText)findViewById(R.id.edit_email);
//Spinner for the phone number field
numberSpinner = (Spinner) findViewById(R.id.contact_number_spinner);
// Create an ArrayAdapter using the string array and a default spinner layout
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
R.array.number_array, android.R.layout.simple_spinner_item);
// Specify the layout to use when the list of choices appears
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// Apply the adapter to the spinner
numberSpinner.setAdapter(adapter);
//Spinner for the email address field
emailSpinner = (Spinner) findViewById(R.id.contact_email_spinner);
adapter = ArrayAdapter.createFromResource(this,
R.array.email_array, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
emailSpinner.setAdapter(adapter);
//Spinner for address field
addressSpinner = (Spinner) findViewById(R.id.contact_address_spinner);
adapter= ArrayAdapter.createFromResource(this,
R.array.address_array, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
addressSpinner.setAdapter(adapter);
//Spinner for date
dateSpinner = (Spinner) findViewById(R.id.contact_date_spinner);
adapter=ArrayAdapter.createFromResource(this,
R.array.date_array, android.R.layout.simple_spinner_dropdown_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
dateSpinner.setAdapter(adapter);
addPic = (ImageButton) findViewById(R.id.addImage);
Bitmap bm = BitmapFactory.decodeResource(getResources(), R.drawable.ic_social_person);
addPic.setImageBitmap(bm);
addPic.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
Intent imageIntent = new Intent(Intent.ACTION_PICK);
imageIntent.setType("image/*");
startActivityForResult(imageIntent, IMAGE_SELECTION);
}
});
}
protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent){
super.onActivityResult(requestCode, resultCode, imageReturnedIntent);
switch(requestCode){
case IMAGE_SELECTION:
if(resultCode == RESULT_OK){
try{
BitmapFactory.Options options = new BitmapFactory.Options();
options.inScaled = true;
final Uri imageURI = imageReturnedIntent.getData();
final InputStream inStr = getContentResolver().openInputStream(imageURI);
final Bitmap selectImg = BitmapFactory.decodeStream(inStr, null, options);
addPic.setImageBitmap(selectImg);
}catch(FileNotFoundException ex){
Log.e("File not found", "Selected image was not found", ex);
}
}
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.add_contact, menu);
return true;
}
public boolean onOptionsItemSelected(MenuItem item){
switch(item.getItemId()){
//if the save button is pressed, then all the information is retrieved from the EditText fields
//and stored in the private fields and then a new contact object is created and added to the
//database
case R.id.action_save:
BitmapDrawable bmd = ((BitmapDrawable) addPic.getDrawable());
Bitmap photo = bmd.getBitmap();
Contact contact = new Contact(firstName.getText().toString(),lastName.getText().toString(),number.getText().toString(), numberSpinner.getSelectedItem().toString(), email.getText().toString(), emailSpinner.getSelectedItem().toString(), date.getText().toString(), dateSpinner.getSelectedItem().toString(), address.getText().toString(), addressSpinner.getSelectedItem().toString(), "false");
//add to database
try {
databaseHandler.openDataBase();
databaseHandler.addContact(contact);
databaseHandler.close();
} catch (SQLException sqle) {
throw sqle;
}
//go back to list of contacts
Intent intentMain = new Intent(getApplicationContext(),MainActivity.class);
intentMain.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intentMain);
return true;
//if the cancel button is pressed on the action bar then the user is navigate to MainActivity
case R.id.action_cancel:
Intent intentCancel = new Intent(this,MainActivity.class);
intentCancel.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intentCancel);
return true;
//if the up button is pressed, then the user is taken back to the MainActivity
case android.R.id.home:
NavUtils.navigateUpFromSameTask(this);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
}
XML文件：
<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:orientation="vertical"
tools:context=".AddContact" >
<TextView
android:id="@+id/lbl_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:layout_marginTop="10dp"
android:text="@string/heading_name"
android:textColor="#0ab2ea" />
<View
android:id="@+id/view_name"
android:layout_width="wrap_content"
android:layout_height="1.5dp"
android:background="@drawable/blue_colour" />
<LinearLayout
android:layout_width="337dp"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:weightSum="6" >
<EditText
android:id="@+id/edit_first_name"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:layout_weight="5"
android:hint="@string/hint_firstname"
android:inputType="textCapSentences" />
<ImageButton
android:id="@+id/addImage"
android:layout_width="0dp"
android:layout_height="58dp"
android:layout_weight="1"
android:background="@drawable/ic_social_person" />
</LinearLayout>
<LinearLayout
android:layout_width="337dp"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:weightSum="6" >
<EditText
android:id="@+id/edit_last_name"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:layout_weight="5"
android:hint="@string/hint_lastname"
android:inputType="textCapSentences" />
</LinearLayout>
<TextView
android:id="@+id/lbl_number"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:text="@string/heading_number"
android:textColor="#0ab2ea" />
<View
android:id="@+id/view_number"
android:layout_width="wrap_content"
android:layout_height="1.5dp"
android:background="@drawable/blue_colour" />
<LinearLayout
android:layout_width="337dp"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:weightSum="3" >
<EditText
android:id="@+id/edit_number"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:layout_marginTop="10dp"
android:layout_weight="2"
android:hint="@string/hint_number"
android:inputType="number" />
<Spinner
android:id="@+id/contact_number_spinner"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:layout_weight="1" />
</LinearLayout>
<TextView
android:id="@+id/lbl_email"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:text="@string/heading_email"
android:textColor="#0ab2ea" />
<View
android:id="@+id/view_email"
android:layout_width="wrap_content"
android:layout_height="1.5dp"
android:background="@drawable/blue_colour" />
<LinearLayout
android:layout_width="337dp"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:weightSum="3" >
<EditText
android:id="@+id/edit_email"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:layout_marginTop="10dp"
android:layout_weight="2"
android:hint="@string/hint_email"
android:inputType="textEmailAddress" />
<Spinner
android:id="@+id/contact_email_spinner"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:layout_weight="1" />
</LinearLayout>
<TextView
android:id="@+id/lbl_address"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:text="@string/heading_address"
android:textColor="#0ab2ea" />
<View
android:id="@+id/view_address"
android:layout_width="wrap_content"
android:layout_height="1.5dp"
android:background="@drawable/blue_colour" />
<LinearLayout
android:layout_width="337dp"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:weightSum="3" >
<EditText
android:id="@+id/edit_address"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:layout_marginTop="10dp"
android:layout_weight="2"
android:hint="@string/hint_address"
android:inputType="textPostalAddress" />
<Spinner
android:id="@+id/contact_address_spinner"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:layout_weight="1" />
</LinearLayout>
<TextView
android:id="@+id/lbl_event"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:text="@string/heading_event"
android:textColor="#0ab2ea" />
<View
android:id="@+id/view_event"
android:layout_width="wrap_content"
android:layout_height="1.5dp"
android:background="@drawable/blue_colour" />
<LinearLayout
android:layout_width="337dp"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:weightSum="3" >
<EditText
android:id="@+id/edit_date"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:layout_marginTop="10dp"
android:layout_weight="2"
android:hint="@string/hint_date"
android:inputType="date" />
<Spinner
android:id="@+id/contact_date_spinner"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1" />
</LinearLayout>
</LinearLayout>
任何帮助都将不胜感激。
答案 0 :(得分：6)
以下是一些可能对您有所帮助的代码：
替换此代码
BitmapFactory.Options options = new BitmapFactory.Options();
options.inScaled = true;
final Uri imageURI = imageReturnedIntent.getData();
final InputStream inStr = getContentResolver().openInputStream(imageURI);
final Bitmap selectImg = BitmapFactory.decodeStream(inStr, null, options);
addPic.setImageBitmap(selectImg);
使用以下代码
final Uri imageURI = imageReturnedIntent.getData();
final InputStream inStr = new BufferedInputStream(getContentResolver().openInputStream(imageURI));
int height = addPic.getHeight();
int width = addPic.getWidth();
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeStream(inStr, null, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, width, height);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
try {
inStr.reset();
} catch (IOException e) {
e.printStackTrace();
}
Bitmap selectImg = BitmapFactory.decodeStream(inStr, null, options);
addPic.setImageBitmap(selectImg);
并将此功能添加到您的班级
public int calculateInSampleSize(
BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
// Calculate ratios of height and width to requested height and width
final int heightRatio = Math.round((float) height / (float) reqHeight);
final int widthRatio = Math.round((float) width / (float) reqWidth);
// Choose the smallest ratio as inSampleSize value, this will guarantee
// a final image with both dimensions larger than or equal to the
// requested height and width.
inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
}
return inSampleSize;
}
有关详细信息，请参阅http://developer.android.com/training/displaying-bitmaps/load-bitmap.html
答案 1 :(得分：2)
尝试在ImageButton上使用此属性：
<ImageButton
android:scaleType="fitXY"
... />
希望这会有所帮助：）
答案 2 :(得分：2)
使用ImageButton的Scale属性：
<ImageButton
android:id="@+id/addImage"
android:layout_width="0dp"
android:layout_height="58dp"
android:layout_weight="1"
android:scaleType="fitXY"
android:background="@drawable/ic_social_person" />
答案 3 :(得分：0)
也许从你的ImageButton xml中取出它
android:layout_weight="1"