我无法理解如何实现我想要的目标。我试图将随机图像加载到drawables文件夹中的图像视图中。我通过获取对所有drawable的引用并将id放入int数组来实现此目的。我随机选择零和最大数组长度之间的数字，并用该图像填充imageview。
当我过度旋转屏幕时会出现问题，而是当我猜错了太多随机图像已加载到内存中时，因为抛出了内存不足异常。
我试图回收使用后的情况，但如果我再次将该图像重新拉回来，我会尝试重复使用回收的位图错误。
问题活动
package com.example.hip_hoptrivia;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.util.SparseArray;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
public class QuestionsActivity extends ActionBarActivity {
private JSONObject dataBase = null;
private JSONArray triviaQuestions = null;
private int currentQuestion = 0, currentDrawable;
//setup random question images
private int[] questionImages = new int[] {R.drawable.boswell_cheo_mural, R.drawable.buddha, R.drawable.dq,
R.drawable.equipment, R.drawable.graffiti, R.drawable.huge_image, R.drawable.rappers, R.drawable.spray_paint,
R.drawable.wza};
private static final String FILE_NAME = "questiondata.txt";
private static final String TAG_QUESTION = "Question";
private static final String TAG_ANSWER = "Answer";
private static final String TAG_INFO = "Info";
private static final String TAG_TRIVIA = "Trivia";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_questions);
createData();
createQuestion();
buttonSetup();
}
@Override
protected void onDestroy() {
super.onDestroy();
/* ImageView imageView = (ImageView)findViewById(R.id.randomImage);
Drawable drawable = imageView.getDrawable();
if (drawable instanceof BitmapDrawable) {
BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
Bitmap bitmap = bitmapDrawable.getBitmap();
bitmap.recycle();
bitmap = null;
}*/
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.questions, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
if(MyUtilities.NavigateActionItems( this , item))
return true;
else
return super.onOptionsItemSelected(item);
}
private void createData(){
String result = MyUtilities.parseLocalFile(this , FILE_NAME);
if( result != null ){
try{
dataBase = new JSONObject( result );
triviaQuestions = dataBase.getJSONArray(TAG_TRIVIA);
}catch( JSONException e ){
e.printStackTrace();
}
}else{
Log.e("Parsing", "coudln't extract");
}
}
private void createQuestion(){
try{
JSONObject s = triviaQuestions.getJSONObject(currentQuestion);
String question = s.getString(TAG_QUESTION);
//Clear Input Text
EditText userInputEditText = (EditText)findViewById(R.id.userInput);
userInputEditText.setText("");
//Place Question Text
TextView questionTextView = (TextView)findViewById(R.id.currentQuestion);
questionTextView.setText(question);
//Create random image that goes with text
ImageView randomImage = (ImageView)findViewById(R.id.randomImage);
//Random number such that [Min + (int)(Math.random() * ((Max - Min) + 1))]
currentDrawable = (int)(Math.random() * ((questionImages.length-1) + 1));
randomImage.setImageResource(questionImages[currentDrawable]);
}catch( JSONException e ){
e.printStackTrace();
}
}
private void checkAnswer(){
try{
JSONObject s = triviaQuestions.getJSONObject(currentQuestion);
String answer = s.getString(TAG_ANSWER);
EditText userInputEditText = (EditText)findViewById(R.id.userInput);
String userAnswer = userInputEditText.getText().toString();
//check if input is correct
if( answer.equalsIgnoreCase(userAnswer)){
++currentQuestion;
createQuestion();
}else{
Toast.makeText(getApplicationContext(), "Wrong",
Toast.LENGTH_LONG).show();
}
}catch( JSONException e ){
e.printStackTrace();
}
}
private void buttonSetup(){
Button submitButton = (Button) findViewById(R.id.submitButton);
submitButton.setOnClickListener( new View.OnClickListener() {
@Override
public void onClick(View v) {
//On input check if correct answer
checkAnswer();
}
});
}
}
布局文件
<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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.hip_hoptrivia.QuestionsActivity" >
<EditText
android:id="@+id/userInput"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="112dp"
android:ems="10" >
<requestFocus />
</EditText>
<TextView
android:id="@+id/currentQuestion"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/userInput"
android:layout_centerHorizontal="true"
android:layout_marginBottom="115dp"
android:text="Medium Text"
android:textAppearance="?android:attr/textAppearanceMedium" />
<Button
android:id="@+id/submitButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="@+id/userInput"
android:layout_centerHorizontal="true"
android:layout_marginTop="48dp"
android:text="Submit" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/randomImage"
android:layout_above="@+id/currentQuestion"
android:layout_centerHorizontal="true" />
</RelativeLayout>
答案 0 :(得分：1)
首先，由于内存不足错误在显示图像时可能是一个严重问题，因此您需要正确引用Displaying Bitmaps Effeciently。
其次
I have tried to recycle the after usage, but if I pull that image back up again i get a trying to reuse recycled bitmap error.
你应该使用
((BitmapDrawable)imageView.getDrawable()).getBitmap().recycle();
在换到新图像之前。
现在，如果您尝试交换已经回收的图像，则无法使用此功能。因此你会得到
Canvas: trying to use a recycled bitmap error
在onDestroy()中，您可以尝试
@Override
public void onDestroy() {
super.onDestroy();
imageView.setImageDrawable(null);
}
将imageView替换为您的ImageView名称。希望这有帮助。