Java 如何让gridview类在单击时调用自己，然后在另一个网格项上单击，引用另一个活动？
另一个类调用下面的GridView类，该类由解析服务器的图像填充，如果用户单击网格项，它将使用不同的绑定字符串启动相同的GridView类，以便可以从不同的解析数据库类中提取。现在，当用户单击一个GridView项目（从设置的第二个GridView）时，我希望它启动一个不同的活动类 我尝试在onItemClick中执行if/else if语句，该语句接受“PARSE_CLASS”绑定字符串，但似乎无法实现。我对android编程比较陌生，所以我不知道最好的方法Java 如何让gridview类在单击时调用自己，然后在另一个网格项上单击，引用另一个活动？,java,android,android-intent,gridview,onitemclick,Java,Android,Android Intent,Gridview,Onitemclick,另一个类调用下面的GridView类，该类由解析服务器的图像填充，如果用户单击网格项，它将使用不同的绑定字符串启动相同的GridView类，以便可以从不同的解析数据库类中提取。现在，当用户单击一个GridView项目（从设置的第二个GridView）时，我希望它启动一个不同的活动类 我尝试在onItemClick中执行if/else if语句，该语句接受“PARSE_CLASS”绑定字符串，但似乎无法实现。我对android编程比较陌生，所以我不知道最好的方法 public class
public class DisplayGrid extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
GridView gridView = null;
List<ParseObject> obj;
ProgressDialog loadProgress;
GridViewAdapter adapter;
Bundle extras = new Bundle();
GridViewAdapter itemGridAdapter;
private List<ImageList> imageArrayList = null;
private List<String> categoryNameArrayList = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.ws_display_grid);
imageArrayList = new ArrayList<ImageList>();
categoryNameArrayList = new ArrayList<String>();
gridView = (GridView) findViewById(R.id.gridView);
itemGridAdapter = new GridViewAdapter(DisplayGrid.this, imageArrayList);
gridView.setAdapter(itemGridAdapter);
new RemoteDataTask().execute();
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
Intent i = getIntent();
Bundle itemExtras = i.getExtras();
final String activeSupplier = itemExtras.getString("SUPPLIER");
String parseClass = extras.getString("PARSE_CLASS");
@Override
public void onItemClick(AdapterView<?> arg0, View v, int position,
long arg3) {
Intent t = new Intent(getApplicationContext(), DisplayGrid.class);
extras.putString("SUPPLIER", activeSupplier);
extras.putString("PARSE_CLASS", "Items");
t.putExtras(extras);
startActivity(t);
}
});
}//end onCreate method
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
@Override
public void onStart() {
super.onStart();
}
@Override
public void onStop() {
super.onStop();
}
//RemoteDataTask
private class RemoteDataTask extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
loadProgress = new ProgressDialog(DisplayGrid.this);
loadProgress.setTitle("Images");
loadProgress.setMessage("Loading...");
loadProgress.setIndeterminate(false);
loadProgress.show();
}
@Override
protected Void doInBackground(Void... params) {
try {
Intent i = getIntent();
Bundle extras = i.getExtras();
String parseClass = extras.getString("PARSE_CLASS");
String activeSupplier = extras.getString("SUPPLIER");
String category;
ParseQuery<ParseObject> query = new ParseQuery<>(parseClass);
query.whereEqualTo("username", activeSupplier);
obj = query.find();
if (parseClass == "Items") {
category = extras.getString("CATEGORY");
query.whereEqualTo("category", category);
}
for (ParseObject categories : obj) {
//get image
ParseFile image = (ParseFile) categories.get("image");
ImageList gridBlock = new ImageList();
gridBlock.setImage(image.getUrl());
imageArrayList.add(gridBlock);
Log.i("AppInfo", "image sent to imageArrayList");
String categoryName = null;
//get category name
if (categoryName == null) {
} else {
categoryName = categories.getString("categoryName");
categoryNameArrayList.add(categoryName);
Log.i("AppInfo", categoryName);
}
}
} catch (ParseException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result) {
gridView = (GridView) findViewById(R.id.gridView);
adapter = new GridViewAdapter(DisplayGrid.this, imageArrayList);
gridView.setAdapter(adapter);
loadProgress.dismiss();
Log.i("AppInfo", "CategoryGrid Populated");
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 1 && resultCode == RESULT_OK && data != null) {
Uri selectedImage = data.getData();
try {
Bitmap bitmapImage =
MediaStore.Images.Media.getBitmap
(this.getContentResolver(), selectedImage);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] byteArray = stream.toByteArray();
//convert to parse file
ParseFile file = new ParseFile("Img.png", byteArray);
ParseObject object = new ParseObject("Categories");
object.put("username", ParseUser.getCurrentUser().getUsername());
object.put("image", file);
object.saveInBackground(new SaveCallback() {
@Override
public void done(ParseException e) {
if (e == null) {
Toast.makeText(getApplication().getBaseContext(), "Your image has been saved", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplication().getBaseContext(), "Upload failed, please try again", Toast.LENGTH_SHORT).show();
}
}
});
} catch (IOException e) {
e.printStackTrace();
Toast.makeText(getApplication().getBaseContext(), "Upload failed, please try again", Toast.LENGTH_SHORT).show();
}
}
}
//begin getTitle method
//begin createMenu
@Override
public boolean onCreateOptionsMenu(Menu menu) {
new MenuInflater(getApplication())
.inflate(R.menu.options, menu);
return (super.onCreateOptionsMenu(menu));
}
//end createMenu
//begin onOptionsItemSelected
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.manufacturers) {
Intent i = new Intent(getApplicationContext(), SupplierList.class);
startActivity(i);
return true;
} else if (item.getItemId() == R.id.add) {
Intent i = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(i, 1);
return true;
} else if (item.getItemId() == R.id.sign_out) {
ParseUser.logOut();
Intent i = new Intent(getApplicationContext(), MainActivity.class);
startActivity(i);
return true;
}
return (super.onOptionsItemSelected(item));
}
//end onOptionsItemSelected
}
if(parseClass == "Categories"){}
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
Intent t = getIntent();
Bundle itemExtras = t.getExtras();
String activeSupplier = itemExtras.getString("SUPPLIER");
String parseClass = itemExtras.getString("PARSE_CLASS");
@Override
public void onItemClick(AdapterView<?> arg0, View v, int position,
long arg3) {
Log.i("AppInfo", parseClass);
if (parseClass.equals("Categories")) {
Log.i("AppInfo", parseClass);
Intent t = new Intent(getApplicationContext(), DisplayGrid.class);
String categoryName = categoryNameArrayList.get(position);
itemExtras.putString("SUPPLIER", activeSupplier);
itemExtras.putString("PARSE_CLASS", "Items");
itemExtras.putString("CATEGORY_NAME", categoryName);
t.putExtras(itemExtras);
startActivity(t);
} else if (parseClass.equals("Items")) {
Intent t = new Intent(getApplicationContext(), ItemDisplay.class);
//extras.putString("SUPPLIER", activeSupplier);
//extras.putString("PARSE_CLASS", "Items");
//t.putExtras(extras);
startActivity(t);
}
}
});
gridView.setOnItemClickListener（新的AdapterView.OnItemClickListener（）{
Intent t=getIntent（）；
Bundle itemExtras=t.getExtras（）；
String activeSupplier=itemExtras.getString（“供应商”）；
String parseClass=itemExtras.getString（“PARSE_CLASS”）；
@凌驾
公共视图单击（AdapterView arg0，视图v，内部位置，
长arg3）{
Log.i（“AppInfo”，parseClass）；
if（parseClass.equals（“类别”））{
Log.i（“AppInfo”，parseClass）；
Intent t=newintent（getApplicationContext（），DisplayGrid.class）；
String categoryName=categoryNameArrayList.get（位置）；
itemExtras.putString（“供应商”，活动供应商）；
putString（“PARSE_CLASS”，“Items”）；
itemExtras.putString（“类别名称”，类别名称）；
t、 额外支出（项目额外支出）；
星触觉（t）；
}else if（parseClass.equals（“Items”））{
Intent t=新的Intent（getApplicationContext（），ItemDisplay.class）；
//额外输入字符串（“供应商”，活动供应商）；
//额外putString（“PARSE_CLASS”，“Items”）；
//t、 临时演员（临时演员）；
星触觉（t）；
}
}
});
公共类DisplayGrid扩展AppCompative活动实现AdapterView.OnItemSelectedListener{
GridView GridView=null；
列出obj；
进步对话；进步；
GridViewAdapter；
Bundle extras=新Bundle（）；
GridViewAdapter项GridAdapter；
私有列表imageArrayList=null；
私有列表categoryNameArrayList=null；
供应商；
字符串解析类；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.ws_display_grid）；
imageArrayList=新建ArrayList（）；
categoryNameArrayList=新ArrayList（）；
Intent i=getIntent（）；
if（null！=i）{
Bundle itemExtras=i.getExtras（）；
activeSupplier=itemExtras.getString（“供应商”）；
parseClass=itemExtras.getString（“PARSE_类”）；
}
RemoteDataTask remoteDataAsync=新的RemoteDataTask（）；
remoteDataAsync.execute（）；
if（remoteDataAsync.getStatus（）==AsyncTask.Status.PENDING）{
//我的任务尚未开始
}
if（remoteDataAsync.getStatus（）==AsyncTask.Status.RUNNING）{
//我的AsyncTask当前正在doInBackground（）中工作
}
if（remoteDataAsync.getStatus（）==AsyncTask.Status.FINISHED）{
//我的AsyncTask已完成，onPostExecute已调用
setOnItemClickListener（新的AdapterView.OnItemClickListener（）{
@凌驾
公共视图单击（AdapterView arg0，视图v，内部位置，
长arg3）{
Intent t=newintent（getApplicationContext（），DisplayGrid.class）；
额外输入字符串（“供应商”，活动供应商）；
putString（“PARSE_类”，parseClass）；
t、 临时演员（临时演员）；
星触觉（t）；
}
});
}
@凌驾
已选择公共视图（AdapterView父视图、视图视图、整型位置、长id）{
}
@凌驾
未选择公共无效（AdapterView父级）{
}
@凌驾
public void onStart（）{
super.onStart（）；
}
@凌驾
公共void onStop（）{
super.onStop（）；
}
//远程数据任务
私有类RemoteDataTask扩展了AsyncTask{
@凌驾
受保护的void onPreExecute（）{
super.onPreExecute（）；
loadProgress=newprogressdialog（DisplayGrid.this）；
loadProgress.setTitle（“图像”）；
setMessage（“正在加载…”）；
loadProgress.setUndeminate（false）；
loadProgress.show（）；
}
@凌驾
受保护的Void doInBackground（Void…参数）{
试一试{
Intent i=getIntent（）；
Bundle extras=i.getExtras（）；
String parseClass=extras.getString（“PARSE_CLASS”）；
String activeSupplier=extras.getString（“供应商”）；
字符串类别；
ParseQuery查询=新的ParseQuery（parseClass）；
查询。whereEqualTo（“用户名”，活动供应商）；
obj=query.find（）；
如果（parseClass==“项目”）{
category=extras.getString（“category”）；
查询：whereEqualTo（“类别”，类别）；
}
用于（对象类别：obj）{
//获取图像
ParseFile image=（ParseFile）categories.get（“image”）；
ImageList gridBlock=新建ImageList（）；
setImage（image.getUrl（））；
if(parseClass == "Categories"){}
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
Intent t = getIntent();
Bundle itemExtras = t.getExtras();
String activeSupplier = itemExtras.getString("SUPPLIER");
String parseClass = itemExtras.getString("PARSE_CLASS");
@Override
public void onItemClick(AdapterView<?> arg0, View v, int position,
long arg3) {
Log.i("AppInfo", parseClass);
if (parseClass.equals("Categories")) {
Log.i("AppInfo", parseClass);
Intent t = new Intent(getApplicationContext(), DisplayGrid.class);
String categoryName = categoryNameArrayList.get(position);
itemExtras.putString("SUPPLIER", activeSupplier);
itemExtras.putString("PARSE_CLASS", "Items");
itemExtras.putString("CATEGORY_NAME", categoryName);
t.putExtras(itemExtras);
startActivity(t);
} else if (parseClass.equals("Items")) {
Intent t = new Intent(getApplicationContext(), ItemDisplay.class);
//extras.putString("SUPPLIER", activeSupplier);
//extras.putString("PARSE_CLASS", "Items");
//t.putExtras(extras);
startActivity(t);
}
}
});
public class DisplayGrid extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
GridView gridView = null;
List<ParseObject> obj;
ProgressDialog loadProgress;
GridViewAdapter adapter;
Bundle extras = new Bundle();
GridViewAdapter itemGridAdapter;
private List<ImageList> imageArrayList = null;
private List<String> categoryNameArrayList = null;
String activeSupplier;
String parseClass;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.ws_display_grid);
imageArrayList = new ArrayList<ImageList>();
categoryNameArrayList = new ArrayList<String>();
Intent i = getIntent();
if (null != i) {
Bundle itemExtras = i.getExtras();
activeSupplier = itemExtras.getString("SUPPLIER");
parseClass = itemExtras.getString("PARSE_CLASS");
}
RemoteDataTask remoteDataAsync = new RemoteDataTask();
remoteDataAsync.execute();
if(remoteDataAsync.getStatus() == AsyncTask.Status.PENDING){
// My AsyncTask has not started yet
}
if(remoteDataAsync.getStatus() == AsyncTask.Status.RUNNING){
// My AsyncTask is currently doing work in doInBackground()
}
if(remoteDataAsync.getStatus() == AsyncTask.Status.FINISHED){
// My AsyncTask is done and onPostExecute was called
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View v, int position,
long arg3) {
Intent t = new Intent(getApplicationContext(), DisplayGrid.class);
extras.putString("SUPPLIER", activeSupplier);
extras.putString("PARSE_CLASS", parseClass);
t.putExtras(extras);
startActivity(t);
}
});
}
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
@Override
public void onStart() {
super.onStart();
}
@Override
public void onStop() {
super.onStop();
}
//RemoteDataTask
private class RemoteDataTask extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
loadProgress = new ProgressDialog(DisplayGrid.this);
loadProgress.setTitle("Images");
loadProgress.setMessage("Loading...");
loadProgress.setIndeterminate(false);
loadProgress.show();
}
@Override
protected Void doInBackground(Void... params) {
try {
Intent i = getIntent();
Bundle extras = i.getExtras();
String parseClass = extras.getString("PARSE_CLASS");
String activeSupplier = extras.getString("SUPPLIER");
String category;
ParseQuery<ParseObject> query = new ParseQuery<>(parseClass);
query.whereEqualTo("username", activeSupplier);
obj = query.find();
if (parseClass == "Items") {
category = extras.getString("CATEGORY");
query.whereEqualTo("category", category);
}
for (ParseObject categories : obj) {
//get image
ParseFile image = (ParseFile) categories.get("image");
ImageList gridBlock = new ImageList();
gridBlock.setImage(image.getUrl());
imageArrayList.add(gridBlock);
Log.i("AppInfo", "image sent to imageArrayList");
String categoryName = null;
//get category name
if (categoryName == null) {
} else {
categoryName = categories.getString("categoryName");
categoryNameArrayList.add(categoryName);
Log.i("AppInfo", categoryName);
}
}
} catch (ParseException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result) {
adapter = new GridViewAdapter(DisplayGrid.this, imageArrayList);
gridView.setAdapter(adapter);
loadProgress.dismiss();
Log.i("AppInfo", "CategoryGrid Populated");
}//end onCreate method
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 1 && resultCode == RESULT_OK && data != null) {
Uri selectedImage = data.getData();
try {
Bitmap bitmapImage =
MediaStore.Images.Media.getBitmap
(this.getContentResolver(), selectedImage);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] byteArray = stream.toByteArray();
//convert to parse file
ParseFile file = new ParseFile("Img.png", byteArray);
ParseObject object = new ParseObject("Categories");
object.put("username", ParseUser.getCurrentUser().getUsername());
object.put("image", file);
object.saveInBackground(new SaveCallback() {
@Override
public void done(ParseException e) {
if (e == null) {
Toast.makeText(getApplication().getBaseContext(), "Your image has been saved", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplication().getBaseContext(), "Upload failed, please try again", Toast.LENGTH_SHORT).show();
}
}
});
} catch (IOException e) {
e.printStackTrace();
Toast.makeText(getApplication().getBaseContext(), "Upload failed, please try again", Toast.LENGTH_SHORT).show();
}
}
}
//begin getTitle method
//begin createMenu
@Override
public boolean onCreateOptionsMenu(Menu menu) {
new MenuInflater(getApplication())
.inflate(R.menu.options, menu);
return (super.onCreateOptionsMenu(menu));
}
//end createMenu
//begin onOptionsItemSelected
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.manufacturers) {
Intent i = new Intent(getApplicationContext(), SupplierList.class);
startActivity(i);
return true;
} else if (item.getItemId() == R.id.add) {
Intent i = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(i, 1);
return true;
} else if (item.getItemId() == R.id.sign_out) {
ParseUser.logOut();
Intent i = new Intent(getApplicationContext(), MainActivity.class);
startActivity(i);
return true;
}
return (super.onOptionsItemSelected(item));
}
//end onOptionsItemSelected
}