java微调器不响应用户
我试图让微调器对用户输入做出反应,但是,当我按下其中一个项目时,什么也没发生。我在IDE中或在运行时没有收到任何错误,所以我不知道我做错了什么。有人能帮忙吗
public class settings extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
String selected;
int themeno;
String [] themes = {"Green with blue (Default)", "Green with red", "Green with orange", "Green with yellow", "Green with green", "Green with pink", "Green with purple"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_settings);
SharedPreferences sharedPref = getApplicationContext().getSharedPreferences("Settings", Context.MODE_PRIVATE);
themeno = sharedPref.getInt("Theme", 1);
Spinner themeSpinner = (Spinner) findViewById(R.id.spinner);
if(themeno == 1){
setTheme(R.style.AppTheme);
themeSpinner.setSelection(1);
} else if (themeno == 2){
setTheme(R.style.AppTheme2);
themeSpinner.setSelection(2);
} else if (themeno == 3){
setTheme(R.style.AppTheme3);
themeSpinner.setSelection(3);
} else if (themeno == 4){
setTheme(R.style.AppTheme4);
themeSpinner.setSelection(4);
} else if (themeno == 5){
setTheme(R.style.AppTheme5);
themeSpinner.setSelection(5);
} else if (themeno == 6){
setTheme(R.style.AppTheme6);
themeSpinner.setSelection(6);
} else if (themeno == 7){
setTheme(R.style.AppTheme7);
themeSpinner.setSelection(7);
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(settings.this, 安卓.R.layout.simple_list_item_1 , themes);
adapter.setDropDownViewResource(安卓.R.layout.simple_spinner_dropdown_item);
themeSpinner.setAdapter(adapter);
}
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
SharedPreferences sharedPref = getApplicationContext().getSharedPreferences("Settings", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPref.edit();
selected = parent.getItemAtPosition(position).toString();
Toast toast = Toast.makeText(getApplicationContext(), "Theme selected. Colours will change when you close settings.", Toast.LENGTH_SHORT);
if(selected == "Green with blue (Default)"){
editor.putInt("Theme", 1);
toast.show();
}
if(selected == "Green with red"){
editor.putInt("Theme", 2);
toast.show();
}
if(selected == "Green with orange"){
editor.putInt("Theme", 3);
toast.show();
}
if(selected == "Green with yellow"){
editor.putInt("Theme", 4);
toast.show();
}
if(selected == "Green with green"){
editor.putInt("Theme", 5);
toast.show();
}
if(selected == "Green with pink"){
editor.putInt("Theme", 6);
toast.show();
}
if(selected == "Green with purple"){
editor.putInt("Theme", 7);
toast.show();
}
}
# 1 楼答案
首先,您需要向微调器添加一个侦听器。在
onCreate
方法中添加这行代码:接下来,
==
运算符返回所有if
语句中的false
您应该使用
.equals()
方法来比较字符串。==
操作符检查对象是否引用了相同的内存位置。在您的例子中,selected
变量和"any of strings in if statement"
不是指同一个对象或内存另一方面,
.equals()
将比较变量的实际内容。因此,通过if
语句得到的结果是false,并且没有执行其中的任何代码