如何创建一个按钮，点击后返回到一个活动，其中已经把值在sharedPref和编辑这些值？我试图使一个应用程序，用户输入他的身高，体重，年龄和选择从收音机组收音机-男性或女性，并点击后“下一步”按钮，它会进入主菜单，在那里它显示用户刚刚输入的值。我做了一个if，它会看这些值是否已经输入过，如果是，它只是跳过活动，它直接进入主菜单。我想做一个按钮编辑，当它被点击回到活动，用户可以编辑他之前输入的值。我张贴我的主活动和我的主菜单下面的代码，P.S.我是新的编码，我不理解一切，这就是为什么我问一个问题，很想看到一个简单的详细解释的步骤，做我想在代码中的东西。谢谢大家！
public class MainActivity extends AppCompatActivity {
EditText enterHeight, enterWeight, enterAge;
private double height;
private double weight;
private double age;
String selectedRadiobut;
Button button;
RadioButton radioMale, radioFemale;
RadioGroup radioGroup;
SharedPreferences sp;
private boolean heightIsValid() {
if (enterHeight.getText().toString().length() == 0) {
enterHeight.setError("Cant be empty");
return false;
}
double height = Double.valueOf(enterHeight.getText().toString());
if (height <= 0) {
enterHeight.setError("Cant be zero");
return false;
}
if (height <= 40 || height > 250) {
enterHeight.setError("Cant be less than 40 cm or more than 250 cm");
return false;
}
return true;
}
private boolean weightIsValid() {
if (enterWeight.getText().toString().length() == 0) {
enterWeight.setError("Cant be empty");
return false;
}
double weight = Double.valueOf(enterWeight.getText().toString());
if (weight <= 0) {
enterWeight.setError("Cant be zero");
return false;
}
if (weight > 600) {
enterWeight.setError("Cant be more than 600 kg");
return false;
}
return true;
}
private boolean ageIsValid() {
if (enterAge.getText().toString().length() == 0) {
enterAge.setError("Cant be empty");
return false;
}
double age = Double.valueOf(enterAge.getText().toString());
if (age <= 0) {
enterAge.setError("Cant be zero");
return false;
}
if (age > 116) {
enterAge.setError("Cant be older than 116 years");
return false;
}
return true;
}
private boolean genderIsSelected() {
if (radioGroup.getCheckedRadioButtonId() == -1) { //checking if the user has selected a option using id
Toast toast = Toast.makeText(this, "Please select gender", Toast.LENGTH_SHORT);
toast.show();
return false;
}
if (radioMale.isChecked()) {
selectedRadiobut = radioMale.getText().toString();
} else if (radioFemale.isChecked()) {
selectedRadiobut = radioFemale.getText().toString();
}
return true;
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getSupportActionBar().hide();
setContentView(R.layout.activity_main);
getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN);
sp = getSharedPreferences("MyUserPrefs", Context.MODE_PRIVATE);
if (sp.contains("height") && sp.contains("weight") && sp.contains("age") && sp.contains("gender")) {
// Values are stored, navigate to MainMenu directly
Intent intent = new Intent(MainActivity.this, MainMenu.class);
startActivity(intent);
} else {
radioMale = (RadioButton) findViewById(R.id.radioMale);
radioFemale = (RadioButton) findViewById(R.id.radioFemale);
button = (Button) findViewById(R.id.button);
enterHeight = (EditText) findViewById(R.id.enterHeight);
enterWeight = (EditText) findViewById(R.id.enterWeight);
enterAge = (EditText) findViewById(R.id.enterAge);
radioGroup = (RadioGroup) findViewById(R.id.radioSex);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (heightIsValid() & weightIsValid() & ageIsValid() & genderIsSelected()) {
height = Double.valueOf(enterHeight.getText().toString());
weight = Double.valueOf(enterWeight.getText().toString());
age = Double.valueOf(enterAge.getText().toString());
SharedPreferences.Editor editor = sp.edit();
editor.putString("height", String.valueOf(Integer.valueOf((int) height)));
editor.putString("weight", String.valueOf(Integer.valueOf((int) weight)));
editor.putString("age", String.valueOf(Integer.valueOf((int) age)));
editor.putString("gender", String.valueOf(selectedRadiobut));
editor.commit();
InputMethodManager imm = (InputMethodManager) getSystemService(getApplicationContext().INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
Intent intent = new Intent(MainActivity.this, MainMenu.class);
startActivity(intent);
}
}
});
}
}字符串
主菜单：
public class Uncategorized {
按钮btnMC、btnFN、btnRec、btnGuides、btnEdit;
public void btnStepClick(View view) {
Intent intent = new Intent(this, StepCounter.class);
startActivity(intent);
}
public void btnCalClick(View view) {
Intent intent = new Intent(this, MacrosCalculator.class);
startActivity(intent);
}
public void btnRecClick(View view){
Intent intent = new Intent(this, Recipes.class);
startActivity(intent);
}
public void btnEditClick(View view){
Log.d("MainMenu", "Edit button clicked");
Intent intent = new Intent(this, MainActivity.class);
startActivity(intent);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getSupportActionBar().hide();
setContentView(R.layout.activity_main_menu);
TextView age1 , height1 , weight1 , gender1;
age1 = (TextView) findViewById(R.id.age1);
height1 = (TextView) findViewById(R.id.height1);
weight1 = (TextView) findViewById(R.id.weight1);
gender1 = (TextView) findViewById(R.id.gender1);
btnMC = (Button) findViewById(R.id.btnMC);
btnFN = (Button) findViewById(R.id.btnFN);
btnRec = (Button) findViewById(R.id.btnRec);
btnGuides = (Button) findViewById(R.id.btnGuides);
btnEdit = (Button) findViewById(R.id.btnEdit);
SharedPreferences sp = getApplicationContext().getSharedPreferences("MyUserPrefs", Context.MODE_PRIVATE);
String height = sp.getString("height" , "");
String weight = sp.getString("weight" , "");
String age = sp.getString("age" , "");
String gender= sp.getString("gender", "");
gender1.setText("Gender: " + gender);
age1.setText("Age: " + age);
height1.setText("Height(cm): " + height);
weight1.setText("Weight(kg): " + weight);
}型
}
我想创建一个按钮编辑，当它被点击回到主活动，但当它被点击，应用程序崩溃。
1条答案
按热度按时间jslywgbw1#
我找到解决办法了！我必须在单击按钮后删除sharedprefs中的值。因此，在buttonClick中，我必须放置sharedprefs，然后是sp.edit（）.remove（“Value”）.commit（）。我在示例中的值是4，因此我放置了其中的4个，如下所示：）。
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