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如何在活動重新啓動時保存編輯文本字段

2016-12-28 51 views
0

試圖創建我的應用程序的一部分，但已經撞牆了。當您從列表中添加下拉列表時，您將轉到新的活動以添加另一個列表。然後，當您返回到活動時，之前的下拉選擇已經消失。如何在活動重新啓動時保存編輯文本字段

是否有保存第一個下拉選擇的方法，以便當您返回活動時仍然存在？

下面是我從下拉菜單中添加選項的代碼。

public String s; 

TextView myLocationText; 
TextView myLocationText2; 
TextView myLocationText3; 
TextView myLocationText4; 
TextView myLocationText5; 

EditText textCheck; 
EditText textCheck2; 
EditText textCheck3; 
EditText textCheck4; 
EditText textCheck5; 

static int i = 1; 

TextView testView; 

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

    s = getIntent().getStringExtra("SELECTED_ACTIVITY"); 

    //Display selected activity in log 
    Log.d("SecondActivity::" + s, "Extra"); 

    textCheck = (EditText) this.findViewById(R.id.sampleTextData); 
    textCheck2 = (EditText) this.findViewById(R.id.sampleTextData2); 
    textCheck3 = (EditText) this.findViewById(R.id.sampleTextData3); 
    textCheck4 = (EditText) this.findViewById(R.id.sampleTextData4); 
    textCheck5 = (EditText) this.findViewById(R.id.sampleTextData5); 

    //Display selected activity 
    if ((textCheck.getText().toString().equals("")) && i == 1) { 
     myLocationText = (TextView) findViewById(R.id.sampleTextData); 
     myLocationText.setText(s); 
     i++; 
    } else if ((textCheck2.getText().toString().equals("")) && i == 2) { 
     myLocationText2 = (TextView) findViewById(R.id.sampleTextData2); 
     myLocationText2.setText(s); 
     i++; 
    } else if ((textCheck3.getText().toString().equals("")) && i == 3) { 
     myLocationText3 = (TextView) findViewById(R.id.sampleTextData3); 
     myLocationText3.setText(s); 
     i++; 
    } else if ((textCheck4.getText().toString().equals("")) && i == 4) { 
     myLocationText4 = (TextView) findViewById(R.id.sampleTextData4); 
     myLocationText4.setText(s); 
     i++; 
    } else if ((textCheck5.getText().toString().equals("")) && i == 5) { 
     myLocationText5 = (TextView) findViewById(R.id.sampleTextData5); 
     myLocationText5.setText(s); 
     i++; 
    }

我已經從上面的代碼編輯了我的代碼，它更乾淨，我還包含了我認爲需要的保存功能，但仍然沒有很多運氣。見下文。

public String s; 

EditText textCheck; 
EditText textCheck2; 
EditText textCheck3; 
EditText textCheck4; 
EditText textCheck5; 

static int i = 1; 

TextView testView; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.view_activity_second); 
    s = getIntent().getStringExtra("SELECTED_ACTIVITY"); 

    //Display selected activity in log 
    Log.d("SecondActivity::" + s, "Extra"); 

    //Look for saved text from activity 
    textCheck = (EditText) this.findViewById(R.id.sampleTextData); 
    if(savedInstanceState != null) { 
     String editTextString = savedInstanceState.getString("textCheck"); 
     textCheck.setText(editTextString); 
    } 
    textCheck2 = (EditText) this.findViewById(R.id.sampleTextData2); 
    if(savedInstanceState != null) { 
     String editTextString2 = savedInstanceState.getString("textCheck2"); 
     textCheck2.setText(editTextString2); 
    } 
    textCheck3 = (EditText) this.findViewById(R.id.sampleTextData3); 
    if(savedInstanceState != null) { 
     String editTextString3 = savedInstanceState.getString("textCheck3"); 
     textCheck3.setText(editTextString3); 
    } 
    textCheck4 = (EditText) this.findViewById(R.id.sampleTextData4); 
    if(savedInstanceState != null) { 
     String editTextString4 = savedInstanceState.getString("textCheck4"); 
     textCheck4.setText(editTextString4); 
    } 
    textCheck5 = (EditText) this.findViewById(R.id.sampleTextData5); 
    if(savedInstanceState != null) { 
     String editTextString5 = savedInstanceState.getString("textCheck5"); 
     textCheck5.setText(editTextString5); 
    } 

    //Display selected activity 
    if ((textCheck.getText().toString().equals("")) && i == 1) { 
     textCheck.setText(s); 
     i++; 
    } else if ((textCheck2.getText().toString().equals("")) && i == 2) { 
     textCheck2.setText(s); 
     i++; 
    } else if ((textCheck3.getText().toString().equals("")) && i == 3) { 
     textCheck3.setText(s); 
     i++; 
    } else if ((textCheck4.getText().toString().equals("")) && i == 4) { 
     textCheck4.setText(s); 
     i++; 
    } else if ((textCheck5.getText().toString().equals("")) && i == 5) { 
     textCheck5.setText(s); 
     i++; 
    } else if (i == 6){ 
     return; 
    } 
} 

//Save text within activity 
@Override 
protected void onSaveInstanceState(Bundle outState) { 
    super.onSaveInstanceState(outState); 
    outState.putString("textCheck", textCheck.getText().toString()); 
    outState.putString("textCheck2", textCheck2.getText().toString()); 
    outState.putString("textCheck3", textCheck3.getText().toString()); 
    outState.putString("textCheck4", textCheck4.getText().toString()); 
    outState.putString("textCheck5", textCheck5.getText().toString()); 
} 

//Retrieve previous activity text 
@Override 
protected void onRestoreInstanceState(Bundle savedInstanceState) { 
    super.onRestoreInstanceState(savedInstanceState); 
    if (savedInstanceState!=null) { 
     textCheck.setText(savedInstanceState.getString("textCheck")); 
     textCheck2.setText(savedInstanceState.getString("textCheck2")); 
     textCheck3.setText(savedInstanceState.getString("textCheck3")); 
     textCheck4.setText(savedInstanceState.getString("textCheck4")); 
     textCheck5.setText(savedInstanceState.getString("textCheck5")); 
    } 
}

來源

2016-12-28 Sam P

+2

使用'onSaveInstanceState（bundle）'並將它返回到'onCreate（bundle）'包中。 –

+1

此代碼將幫助您：http://android-er.blogspot.in/2011/09/onsaveinstancestate-and.html – Anjali

+3

可能重複[何時使用saveInstanceState（）方法？]（http://stackoverflow.com/questions-18208611/when-to-use-saveinstancestate-method） –

回答

1

在活動中重寫OnSaveInstanceState()，並使用唯一鍵將所有需要的值放入捆綁包中。如：

@Override 
protected void onSaveInstanceState(Bundle outState) { 
    super.onSaveInstanceState(outState); 
    outState.putString("EDITTEXT", mEditText.getText().toString()); 
}

使用相同的密鑰檢索onCreate(Bundle savedInstanceState)中的值。像：

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.view_activity_second); 
    textCheck = (EditText) this.findViewById(R.id.sampleTextData); 
    //this will be false for first time but will be true when activity recreates. 
    if(savedInstanceState != null) { 
     String editTextString = savedInstanceState.getString("EDITTEXT"); 
     textCheck.setText(editTextString); 
    } 
}

來源

2016-12-28 10:45:16

+0

感謝你們這樣做，我創建了onSaveInstanceState方法，並在我的onCreate方法中添加了代碼，但是當我返回到活動時，似乎仍然消失了。 –

0

保存的EditText的內容共享偏好

SharedPreferences.Editor editor = getSharedPreferences(preferences1, 
MODE_PRIVATE).edit(); 
editor.putString("text", "editTextsString"); 
editor.commit();

然後在活動建立或恢復，調用與共享偏好：

SharedPreferences prefs = getSharedPreferences(preferences1, MODE_PRIVATE); 
String Text = prefs.getString("text", null);

，並設置編輯文本字符串變量：Text

來源

2016-12-28 10:46:24

+0

當你有'onSaveInstanceState（）'爲什麼要做像sharedPreference這樣的代價高昂的操作。 –

+0

這是解決操作問題的唯一方法 - 也許不是最平穩的，但我認爲它會達到操作的要求。 –

0 
public String s; 

TextView myLocationText; 
TextView myLocationText2; 
TextView myLocationText3; 
TextView myLocationText4; 
TextView myLocationText5; 

EditText textCheck; 
EditText textCheck2; 
EditText textCheck3; 
EditText textCheck4; 
EditText textCheck5; 

static int i = 1; 

TextView testView; 

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

    s = getIntent().getStringExtra("SELECTED_ACTIVITY"); 

    //Display selected activity in log 
    Log.d("SecondActivity::" + s, "Extra"); 

    textCheck = (EditText) this.findViewById(R.id.sampleTextData); 
    textCheck2 = (EditText) this.findViewById(R.id.sampleTextData2); 
    textCheck3 = (EditText) this.findViewById(R.id.sampleTextData3); 
    textCheck4 = (EditText) this.findViewById(R.id.sampleTextData4); 
    textCheck5 = (EditText) this.findViewById(R.id.sampleTextData5); 

    //Display selected activity 
    if ((textCheck.getText().toString().equals("")) && i == 1) { 
     myLocationText = (TextView) findViewById(R.id.sampleTextData); 
     myLocationText.setText(s); 
     i++; 
    } else if ((textCheck2.getText().toString().equals("")) && i == 2) { 
     myLocationText2 = (TextView) findViewById(R.id.sampleTextData2); 
     myLocationText2.setText(s); 
     i++; 
    } else if ((textCheck3.getText().toString().equals("")) && i == 3) { 
     myLocationText3 = (TextView) findViewById(R.id.sampleTextData3); 
     myLocationText3.setText(s); 
     i++; 
    } else if ((textCheck4.getText().toString().equals("")) && i == 4) { 
     myLocationText4 = (TextView) findViewById(R.id.sampleTextData4); 
     myLocationText4.setText(s); 
     i++; 
    } else if ((textCheck5.getText().toString().equals("")) && i == 5) { 
     myLocationText5 = (TextView) findViewById(R.id.sampleTextData5); 
     myLocationText5.setText(s); 
     i++; 
    } 


} 

@Override 
protected void onSaveInstanceState(Bundle outState) { 
    super.onSaveInstanceState(outState); 
    outState.putString("textCheck", textCheck.getText().toString()); 
    outState.putString("textCheck2", textCheck2.getText().toString()); 
    outState.putString("textCheck3", textCheck3.getText().toString()); 
    outState.putString("textCheck4", textCheck4.getText().toString()); 
    outState.putString("textCheck5", textCheck5.getText().toString()); 
} 

@Override 
protected void onRestoreInstanceState(Bundle savedInstanceState) { 
    super.onRestoreInstanceState(savedInstanceState); 
    if (savedInstanceState!=null) { 
     textCheck.setText(savedInstanceState.getString("textCheck")); 
     textCheck2.setText(savedInstanceState.getString("textCheck2")); 
     textCheck3.setText(savedInstanceState.getString("textCheck3")); 
     textCheck4.setText(savedInstanceState.getString("textCheck4")); 
     textCheck5.setText(savedInstanceState.getString("textCheck5")); 
    } 
}

只需複製並粘貼此代碼即可。希望它會起作用。

來源

2016-12-28 11:01:35

+0

不幸的是，添加了兩個底部方法，但仍然沒有保存。 –

+0

它顯示任何錯誤？ –

+0

沒有錯誤，應用程序繼續工作。由於i ++，它會將其他活動添加到下面的字段中，但上面的字段在返回到活動時似乎仍然是空白的。 –

0 
Use OnSaveInstanceState() to save the value during restart of an activity . 

use below code : 

@Override 
protected void onSaveInstanceState(Bundle bundle) { 
    super.onSaveInstanceState(bundle); 
    bundle.putString("Key","Edit Text value"); 
} 

and get the data using below code : 


@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity); 
    if(savedInstanceState != null) { 
     String value = savedInstanceState.getString("Key"); 
    } 
}

來源

2016-12-28 11:02:51

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