Java 从内存中动态更改android中的列表视图图像
我有一个带有图像的列表视图。我想在ActivityResult上更改列表项图像 图像捕获。我得到图像文件位图,但当我更改列表项图像时,列表视图图像不会更改Java 从内存中动态更改android中的列表视图图像,java,android,listview,bitmap,Java,Android,Listview,Bitmap,我有一个带有图像的列表视图。我想在ActivityResult上更改列表项图像 图像捕获。我得到图像文件位图,但当我更改列表项图像时,列表视图图像不会更改 final Bitmap bitmap = BitmapFactory.decodeFile(fileUri.getPath(), options); imageView1.setImageBitmap(bitmap);//there a bitmap exist---
final Bitmap bitmap = BitmapFactory.decodeFile(fileUri.getPath(),
options);
imageView1.setImageBitmap(bitmap);//there a bitmap exist---
dataAdapter.taskList.get(0).setImgBitmap(bitmap);
//这不是更改列表图像。为什么???????
dataAdapter.notifyDataSetChanged();
这里,imageview1
有一个位图,我使用CustomAdapter
类的ArrayList taskList
参数将其设置为列表的第一项
这里是完整的示例代码
notifyActivity.java
package com.aci.notification;
public class NotifyActivity extends Activity {
// Activity request codes
private static final int CAMERA_CAPTURE_IMAGE_REQUEST_CODE = 100;
public static final int MEDIA_TYPE_IMAGE = 1;
// directory name to store captured images and videos
private static final String IMAGE_DIRECTORY_NAME = "Hello Camera";
private Uri fileUri; // file url to store image/video
private ImageView imageView1;
Bitmap bm, bm2;
private Button btnCapturePicture;
ArrayList<Task> taskList = new ArrayList<Task>();
TextView tv;
CustomAdapter dataAdapter = null;
Button btnSave;
ListView listView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_notify);
btnCapturePicture = (Button) findViewById(R.id.btnCapturePicture);
imageView1 = (ImageView) findViewById(R.id.imageView1);
tv = (TextView) findViewById(R.id.textViewtest);
btnSave = (Button) findViewById(R.id.button1);
listView = (ListView) findViewById(R.id.listView1);
new BitmapFactory();
bm = BitmapFactory.decodeResource(getApplicationContext()
.getResources(), R.drawable.ic_launcher);
bm2 = BitmapFactory.decodeResource(getApplicationContext()
.getResources(), R.drawable.bydefault);
Task task;
task = new Task(0, "This is task1", "/pictures/hello camera/", bm,false);
taskList.add(task);
task = new Task(1, "This is task2", "/pictures/hello camera/", bm,false);
taskList.add(task);
task = new Task(0, "This is task3", "/pictures/hello camera/", bm,false);
taskList.add(task);
task = new Task(0, "This is task4", "/pictures/hello camera/", bm2,false);
taskList.add(task);
task = new Task(0, "This is task5", "/pictures/hello camera/", bm,false);
taskList.add(task);
dataAdapter = new CustomAdapter(this, R.layout.list_style, taskList);
listView.setAdapter(dataAdapter);
}
/**
* Receiving activity result method will be called after closing the camera
* */
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// if the result is capturing Image
if (requestCode == CAMERA_CAPTURE_IMAGE_REQUEST_CODE) {
if (resultCode == RESULT_OK) {
// successfully captured the image
// display it in image view
previewCapturedImage();
}
}
}
/**
* Display image from a path to ImageView
*/
private void previewCapturedImage() {
try {
imageView1.setVisibility(View.VISIBLE);
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 8;
final Bitmap bitmap = BitmapFactory.decodeFile(fileUri.getPath(),
options);
imageView1.setImageBitmap(bitmap);
dataAdapter.taskList.get(0).setImgBitmap(bitmap);
dataAdapter.notifyDataSetChanged();
} catch (NullPointerException e) {
e.printStackTrace();
}
}
public Uri getOutputMediaFileUri(int type) {
return Uri.fromFile(getOutputMediaFile(type));
}
}
public class CustomAdapter extends ArrayAdapter<Task> {
public ArrayList<Task> taskList;
Context context;
public CustomAdapter(Context context, int resource, ArrayList<Task> taskList) {
super(context, resource, taskList);
this.context=context;
// TODO Auto-generated constructor stub
this.taskList = new ArrayList<Task>();
this.taskList.addAll(taskList);
}
private class ViewHolder {
CheckBox task;
ImageView imageView;
int task_id;
Button imageCaptureBtnButton;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
ViewHolder viewHolder = null;
Log.v("ConvertView", String.valueOf(position));
if (convertView == null) {
LayoutInflater vi =(LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = vi.inflate(R.layout.list_style, null);
viewHolder = new ViewHolder();
viewHolder.task_id=taskList.get(position).getTask_id();//set task id of that task
viewHolder.task = (CheckBox) convertView.findViewById(R.id.checkBox1);
viewHolder.imageView=(ImageView) convertView.findViewById(R.id.imgPreview);
viewHolder.imageCaptureBtnButton=(Button) convertView.findViewById(R.id.btnCapturePicture);
viewHolder.imageView.setImageBitmap(taskList.get(position).getImgBitmap());
convertView.setTag(viewHolder);
viewHolder.task.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
CheckBox cb = (CheckBox) v;
Task aTask =(Task) cb.getTag();
Toast.makeText(context,
"Clicked on Checkbox: " + cb.getText() + " is "
+ cb.isChecked(), Toast.LENGTH_LONG).show();
aTask.setSelected(cb.isChecked());
}
});
viewHolder.imageCaptureBtnButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Toast.makeText(context, "dddd", Toast.LENGTH_LONG).show();
}
});
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
Task aTask = taskList.get(position);
viewHolder.task.setText(taskList.get(position).getTask());
viewHolder.task.setChecked(taskList.get(position).isSelected());
viewHolder.task.setTag(aTask);
return convertView;
}
@Override
public long getItemId(int arg0) {
return 0;
}
@Override
public int getCount() {
return taskList.size();
}
@Override
public Task getItem(int arg0) {
return null;
}
}
public class Task {
int task_id = 0;
String task = null;
String imageURL=null;
Bitmap imgBitmap;
boolean selected=false;
public Task(int task_id, String task, String imageURL,Bitmap imgBitmap, boolean selected) {
super();
this.task_id = task_id;
this.task= task;
this.imageURL=imageURL;
this.imgBitmap=imgBitmap;
this.selected = selected;
}
//all getters and setters here
}
我失去了我的日子。请帮帮我。过了很长时间,我找到了自己的问题答案。 代码与这个问题不完全匹配,因为答案来自我的另一个项目。我只是给出了我成功的方式 第1步: 捕获图像时,我称之为imagedata(位图)。它将每个位图转换为base_64字符串,此方法将新图像作为ByteDrawable类型的数组元素添加到列表中 我再次创建新的适配器对象,并将该适配器设置为 列表视图
private class CustomAdapter extends ArrayAdapter<ByteDrawable>{
public CustomAdapter(Context context, int resource, ArrayList<ByteDrawable > byteDrawableList) {
super(context, resource, byteDrawableList);
this.context=context;
this.byteDrawableList= new ArrayList<ByteDrawable >();
this.byteDrawableList.addAll(byteDrawableList);
inflater = LayoutInflater.from(context);
long k = 0;
for (ByteDrawable bd : byteDrawableList) {
String base = bd.getImageByteString();
byte[] imageAsBytes = Base64.decode(base.getBytes(),
Base64.DEFAULT);
items.add(new Item(k, BitmapFactory.decodeByteArray(
imageAsBytes, 0, imageAsBytes.length)));
k++;
}
}
private class Item {
final long itmeid;
final Bitmap drawabledata;
Item(long id, Bitmap bitmap) {
this.itmeid = id;
this.drawabledata = bitmap;
}
}
public View getView(final int position, View view, ViewGroup viewGroup) {
/* follow normal way to set data to list item*/
}
@Override
public int getCount() {
return items.size();
}
@Override
public Object getItem(int i) {
return items.get(i);
}
@Override
public long getItemId(int i) {
return items.get(i).itmeid;
}
}
第二步:
然后,我从该arraylist填充列表,在适配器类的构造函数中,我将base_64
字符串转换为位图,并将元素添加到本地arraylistitems
,然后在getview()
方法中,我使用items创建listview
private class CustomAdapter extends ArrayAdapter<ByteDrawable>{
public CustomAdapter(Context context, int resource, ArrayList<ByteDrawable > byteDrawableList) {
super(context, resource, byteDrawableList);
this.context=context;
this.byteDrawableList= new ArrayList<ByteDrawable >();
this.byteDrawableList.addAll(byteDrawableList);
inflater = LayoutInflater.from(context);
long k = 0;
for (ByteDrawable bd : byteDrawableList) {
String base = bd.getImageByteString();
byte[] imageAsBytes = Base64.decode(base.getBytes(),
Base64.DEFAULT);
items.add(new Item(k, BitmapFactory.decodeByteArray(
imageAsBytes, 0, imageAsBytes.length)));
k++;
}
}
private class Item {
final long itmeid;
final Bitmap drawabledata;
Item(long id, Bitmap bitmap) {
this.itmeid = id;
this.drawabledata = bitmap;
}
}
public View getView(final int position, View view, ViewGroup viewGroup) {
/* follow normal way to set data to list item*/
}
@Override
public int getCount() {
return items.size();
}
@Override
public Object getItem(int i) {
return items.get(i);
}
@Override
public long getItemId(int i) {
return items.get(i).itmeid;
}
}
私有类CustomAdapter扩展了ArrayAdapter{
公共CustomAdapter(上下文上下文、int资源、ArrayList byteDrawableList){
super(上下文、资源、byteDrawableList);
this.context=context;
this.byteDrawableList=newArrayList();
this.bytedrawalblist.addAll(bytedrawalblist);
充气器=充气器。从(上下文);
长k=0;
for(ByteDrawable bd:ByteDrawable列表){
String base=bd.getImageByteString();
byte[]imageAsBytes=Base64.decode(base.getBytes(),
Base64(默认);
items.add(新项)(k,BitmapFactory.decodeByteArray(
imageAsBytes,0,imageAsBytes.length));
k++;
}
}
私人类项目{
最后的长itmeid;
最终位图可绘制数据;
项目(长id、位图){
this.itmeid=id;
this.drawabledata=位图;
}
}
公共视图getView(最终整数位置、视图视图、视图组视图组){
/*按照常规方法将数据设置为列表项*/
}
@凌驾
public int getCount(){
返回items.size();
}
@凌驾
公共对象getItem(int i){
返回项目。获取(i);
}
@凌驾
公共长getItemId(int i){
返回项目。获取(i)。itmeid;
}
}
希望这能帮助那些面临同样问题的人