在選定的餅圖值上創建刪除對話框？

Question

我使用MPAndroidChart庫創建了這個android應用程序，該庫允許用戶使用ArrayList創建一個快速PieChart（我添加了一些截圖，以進行說明）。

我的問題是，我想讓用戶從餅圖（和數組列表）中刪除一個條目，然後應該在沒有刪除條目的情況下呈現餅圖。

有沒有什麼辦法可以讓用戶長按一個項目來打開某種yes/no對話框？

Screenshots gallery

代碼：

package com.example.quickpie; 



public class Main extends AppCompatActivity { 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    final List<PieEntry> entries = new ArrayList<>(); 

    final EditText editText = (EditText) findViewById(R.id.editText); 
    final EditText editText2 = (EditText) findViewById(R.id.editText2); 
    final EditText editText3 = (EditText) findViewById(R.id.editText3); 
    final Button button = (Button) findViewById(R.id.button); 
    final Button button2 = (Button) findViewById(R.id.button2); 
    final TextView textView = (TextView) findViewById(R.id.textView); 
    final TextView textView2 = (TextView) findViewById(R.id.textView2); 
    final TextView textView3 = (TextView) findViewById(R.id.textView3); 

    editText.requestFocus(); 

    button.setOnClickListener(new View.OnClickListener() { 
            public void onClick (View v) { 

             //if(editText.getFreezesText()) 

             if (editText.getText().toString().matches("")) { 
              Toast.makeText(getBaseContext(), "You did not enter a Valid Item ID", Toast.LENGTH_LONG).show(); 
              return; 
             } 

             else if (editText2.getText().toString().matches("")) { 
              Toast.makeText(getBaseContext(), "You did not enter a Valid Quantitiy", Toast.LENGTH_LONG).show(); 
              return; 

             } 

             else { 












             String nomen = (editText.getText().toString()); 
             float number = Float.parseFloat(editText2.getText().toString()); 



              final PieChart piechart = (PieChart) findViewById(R.id.piechart); 
              entries.add(new PieEntry(number, nomen)); 

              editText.setText(""); 
              editText2.setText(""); 
              textView3.setSingleLine(false); 
              textView3.append("\n" + nomen + " " + number); 
              editText.requestFocus(); 


              PieDataSet set = new PieDataSet(entries, ""); 


              //colors 

              getResources().getColor(R.color.violp); 
              getResources().getColor(R.color.bluep); 
              getResources().getColor(R.color.redp); 
              getResources().getColor(R.color.greenp); 
              getResources().getColor(R.color.yellowp); 
              getResources().getColor(R.color.orangep); 
              getResources().getColor(R.color.lightbluep); 
              getResources().getColor(R.color.purplep); 
              getResources().getColor(R.color.darkredp); 


              set.setColors(new int[]{R.color.bluep, R.color.greenp, R.color.violp, R.color.redp, R.color.yellowp, R.color.orangep, R.color.lightbluep, R.color.purplep, R.color.darkredp}, getApplicationContext()); 
              PieData data = new PieData(set); 
              piechart.setData(data); 


              Description description = new Description(); 
              description.setText(getResources().getString(R.string.besch)); 
              piechart.setDescription(description); 

              Toast.makeText(getBaseContext(), (R.string.loading), 
                Toast.LENGTH_SHORT).show(); 


              String mitte = (editText3.getText().toString()); 
              piechart.setCenterText(mitte); 


              piechart.setCenterTextSize(30); 
              piechart.setNoDataText(String.valueOf(R.string.nodata)); 
              piechart.notifyDataSetChanged(); 

              piechart.animateX(2000, Easing.EasingOption.EaseInExpo); 
              piechart.animateY(2000, Easing.EasingOption.EaseInExpo); 

              piechart.invalidate(); 
              editText3.setVisibility(View.VISIBLE); 

              editText3.setOnEditorActionListener(new TextView.OnEditorActionListener() { 
               @Override 
               public boolean onEditorAction(TextView v, int actionId, KeyEvent event) { 
                if (actionId == EditorInfo.IME_ACTION_DONE) { 

                 String mitte = (editText3.getText().toString()); 
                 piechart.setCenterText(mitte); 
                 editText3.setText(""); 
                 editText.requestFocus(); //editText3.setVisibility(View.INVISIBLE); 

                 InputMethodManager imm = (InputMethodManager) getSystemService(Main.INPUT_METHOD_SERVICE); 
                 imm.hideSoftInputFromWindow(editText.getWindowToken(), 0); 


                 //do something 
                } 
                return false; 
               } 
              }); 

              editText3.setOnTouchListener(new View.OnTouchListener() { 
               @Override 
               public boolean onTouch(View v, MotionEvent event) { 
                if (MotionEvent.ACTION_UP == event.getAction()) { 
                 piechart.setCenterText(""); 
                 textView3.setHint(R.string.hint1); 

                } 

                return false; // return is important... 
               } 
              }); 


              button.setOnLongClickListener(new View.OnLongClickListener() { 

               @Override 
               public boolean onLongClick(View v) { 

                Toast.makeText(getBaseContext(), R.string.longpresshint, Toast.LENGTH_LONG).show(); 

                return true; 
               } 
              }); 



















              final Button button2 = (Button) findViewById(R.id.button2); 
              button2.setOnClickListener(new View.OnClickListener() { 


               @Override 
               public void onClick(View v) { 
                String mitte = (editText3.getText().toString()); 
                piechart.setCenterText(mitte); 
                //piechart.setVisibility(View.VISIBLE); 
                //editText.setVisibility(View.INVISIBLE); 
                //textView2.setVisibility(View.INVISIBLE); 
                //textView3.setVisibility(View.INVISIBLE); 
                //editText3.setVisibility(View.INVISIBLE); 
                // editText2.setVisibility(View.INVISIBLE); 
                //button.setVisibility(View.INVISIBLE); 
                //button2.setVisibility(View.INVISIBLE); 

                Toast.makeText(getBaseContext(), (R.string.loading), 
                  Toast.LENGTH_SHORT).show(); 


                piechart.animateX(2000, Easing.EasingOption.EaseInExpo); 
                piechart.animateY(2000, Easing.EasingOption.EaseInExpo); 

                InputMethodManager imm = (InputMethodManager) getSystemService(Main.INPUT_METHOD_SERVICE); 
                imm.hideSoftInputFromWindow(editText.getWindowToken(), 0); 


               } 


              }); 
             }} 
    } 
    ) 
    ; 
} 

@Override 
public void onBackPressed(){ 
    super.onBackPressed(); 
    Intent intent = getIntent(); 
    finish(); 
    startActivity(intent); 


} 



} 

Answer 1

請試試這個

button.setOnClickListener(new View.OnClickListener() { 
            public void onClick (View v) { 

             //if(editText.getFreezesText()) 

             if (editText.getText().toString().matches("")) { 
              Toast.makeText(getBaseContext(), "You did not enter a Valid Item ID", Toast.LENGTH_LONG).show(); 
              return; 
             } 

             else if (editText2.getText().toString().matches("")) { 
              Toast.makeText(getBaseContext(), "You did not enter a Valid Quantitiy", Toast.LENGTH_LONG).show(); 
              return; 

             } 

             else { 
piechart.invalidate(); 

}