<分区>
我搜索了如何在 Android 中使用 SharedPreferences，但遇到了问题。
我在 SP 中保存了一些 Strings 并以这种方式将数据保存在 Main Activity 中:
在 OnCrete 函数中我定义:
sp = getApplicationContext().getSharedPreferences("MyPref", 0); // 0 - for private mode
SharedPreferences.Editor editor = sp.edit();
然后我按以下方式将字符串保存到 SharedPreferences:
mail = edmail.getText().toString();
pass = edpass.getText().toString();
color = edcolor.getText().toString();
phone = edphone.getText().toString();
SharedPreferences.Editor editor = sp.edit();
if (mail.equals("") || pass.equals("") || color.equals("") || phone.equals("")||img.getDrawable() == null
)
Toast.makeText(getApplicationContext(), "you have to fill all the fields", Toast.LENGTH_SHORT).show();
else {
editor.putString("mail", mail);
editor.putString("phone", phone);
editor.putString("color", color);
editor.putString("password", pass);
editor.apply();
Toast.makeText(getApplicationContext(), "Signed up", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(this, Main2Activity.class);
intent.putExtra("img",bitmap);
startActivity(intent);
}
在第二个 Activity 中，我尝试检索数据:
@Override
public void onClick(View v) {
Intent intent=getIntent();
Bitmap bitmap = (Bitmap) intent.getParcelableExtra("img");
imgv.setImageBitmap(bitmap);
LoadPreferences();
//txtmail.setText(value);
}
private void LoadPreferences(){
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
String data = sharedPreferences.getString("mail", null) ;
Toast.makeText(this,data, Toast.LENGTH_LONG).show();
}
toast 显示默认值而不是实际值。