试图创建我的应用程序的一部分,但已经撞墙了。当您从列表中添加下拉列表时,您将转到新的活动以添加另一个列表。然后,当您返回到活动时,之前的下拉选择已经消失。如何在活动重新启动时保存编辑文本字段
是否有保存第一个下拉选择的方法,以便当您返回活动时仍然存在?
下面是我从下拉菜单中添加选项的代码。
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++;
}
我已经从上面的代码编辑了我的代码,它更干净,我还包含了我认为需要的保存功能,但仍然没有很多运气。见下文。
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"));
}
}
使用'onSaveInstanceState(bundle)'并将它返回到'onCreate(bundle)'包中。 –
此代码将帮助您:http://android-er.blogspot.in/2011/09/onsaveinstancestate-and.html – Anjali
可能重复[何时使用saveInstanceState()方法?](http://stackoverflow.com/questions-18208611/when-to-use-saveinstancestate-method) –