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我是全新的android和嘗試創建一個活動，其中有一個片段。這個想法是片段有3個ImageButtons。您單擊的ImageButton會將其圖像傳遞給活動，然後將其顯示在主活動內的onClick（全屏ImageView）之後創建的另一個片段中。問題是我無法弄清楚如何傳遞信息。我已經閱讀了許多類似於這個問題的問題，並且瀏覽了android開發者網站，但是我讀得越多，它就越容易混淆。我也遇到了findViewById的問題，說它無法解決該方法。我不知道爲什麼它告訴我這一點，並嘗試了很多事情來解決它，沒有任何工作。這是我的代碼和任何建議，將不勝感激。通過ImageButton值
主要活動：
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends AppCompatActivity implements MainActivityFragment.CanPassData{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
public void passData(int value){
MainActivityFragment fragment = new MainActivityFragment();
fragment.setData(5);
getSupportFragmentManager().beginTransaction().add(R.id.fragment, fragment).commit();
//***Taken From Android Developer, I believe this is how you create a new fragment when you pass the data to the main activity****
if (fragment != null) {
fragment.getData();
} else {
MainActivityFragment newFragment = new MainActivityFragment();
Bundle args = new Bundle();
//******No idea what this is calling, pictureChosen and picture are default values taken from the website*******
args.putInt(MainActivityFragment.pictureChosen, picture);
newFragment.setArguments(args);
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.fragment, newFragment);
transaction.addToBackStack(null);
transaction.commit();
}
//*****************************************************************************************
}
public void processData(){
MainActivityFragment fragment = (MainActivityFragment) getSupportFragmentManager().findFragmentById(R.id.fragment);
int value = fragment.getData();
}
}
片段：
import android.content.Intent;
import android.graphics.drawable.Drawable;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.ImageView;
public class MainActivityFragment extends Fragment implements View.OnClickListener {
private int data;
private CanPassData parent;
public interface CanPassData{
public void passData(int value);
}
public MainActivityFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
//***findViewById is saying it cannot resolve below
setContentView(R.layout.fragment_main);
ImageButton button1 = (ImageButton) findViewById(R.id.imageButton);
ImageButton button2 = (ImageButton) findViewById(R.id.imageButton2);
ImageButton button3 = (ImageButton) findViewById(R.id.imageButton3);
button1.setOnClickListener(this);
button2.setOnClickListener(this);
button3.setOnClickListener(this);
//******************************************************************************************
return inflater.inflate(R.layout.fragment_main, container, false);
}
public void onAttach(MainActivity activity){
parent = (CanPassData) activity;
}
public void setData(int value){
data = value;
}
//***onClick also has all findViewByID as cannot resolve method, and i'm not exactly sure what to do within each case, the stuff I have in there was also taken from android developer.
@Override
public void onClick(View v){
switch (v.getId()) {
case R.id.imageButton:
ImageView box = (ImageView)findViewByID(R.id.imageButton);
Drawable name = box.getBackground().getCurrent();
Intent intent = new Intent (this, newFragment.class);
intent.putExtra("com.example.coding.assignment2", name);
startActivity(intent);
break;
case R.id.imageButton2:
box = (ImageView)findViewByID(R.id.imageButton2);
name = box.getBackground().getCurrent();
intent = new Intent (this, newFragment.class);
intent.putExtra("com.example.coding.assignment2", name);
startActivity(intent);
break;
case R.id.imageButton3:
box = (ImageView)findViewByID(R.id.imageButton3);
name = box.getBackground().getCurrent();
intent = new Intent (this, newFragment.class);
intent.putExtra("com.example.coding.assignment2", name);
startActivity(intent);
break;
}
}
public void pushData(){
parent.passData(data);
}
public int getData(){
return data;
}
}
了很多方法，如的getData和pushData我不完全知道如何使用獲得的信息的主要活動，這是在課堂上給我的信息。我想知道是否有一種方法可以將drawable本身傳遞給click，然後將該drawable分配給新的fragment中的ImageView，從而顯示它覆蓋整個片段。我被告知我需要創建第二個片段xml，但是java文件本身應該通過主要活動創建。它是否正確？
笑。這可能會讓人困惑，因爲有多種方法可以做到這一點，那麼該怎麼做？既然你打算從片段 - >活動 - >片段，你可以創建一個新的類文件，命名爲（例如）全局變量，你可以在其中定義一個靜態的drawable或其他東西。 OnClick事件將圖像放入靜態全局繪圖和bam！你可以在任何地方使用它，而無需在任何地方編寫代碼。作爲它的靜態，你需要確保內存泄漏和使用，但它的可重用雖然可以重用。 – CmosBattery