Question

我是Android的新人。我试图为不同的字符串阵列组成一个有条件的适配器(取决于字符串变量)。

    TextView textPrompt;
    textPrompt = (TextView)findViewById(R.id.textprompt);
    final String acType = i.getStringExtra("type");
    textPrompt.setText(acType);
    if (acType == "400G"){
    spinnerSurface = (Spinner) findViewById(R.id.spinnerSurface);
    ArrayAdapter<CharSequence> adapterSurface = ArrayAdapter.createFromResource(
            this, R.array.surface_option_1, android.R.layout.simple_spinner_item);
    adapterSurface.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinnerSurface.setAdapter(adapterSurface);

    }
    else if (acType != "400G"){
        spinnerSurface = (Spinner) findViewById(R.id.spinnerSurface);
        ArrayAdapter<CharSequence> adapterSurface = ArrayAdapter.createFromResource(
                this, R.array.surface_option, android.R.layout.simple_spinner_item);
        adapterSurface.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinnerSurface.setAdapter(adapterSurface);

    }

    spinnerSurface.setOnItemSelectedListener(new Spinner.OnItemSelectedListener() { 
        public void onItemSelected(AdapterView<?> parent, View v, 
                int position, long id) { 
            TextView tx = (TextView)v; 
            Log.i("

id",String.valueOf(tx.getText()));
        } 
        public void onNothingSelected(AdapterView<?> arg0) { 
            // TODO Auto-generated method stub 
        } 
    });

I use a textPrompt to check value of acType. No matter acType is "400G" or not "400G", program will take acType as not "400G" thus R.array.surface_option is taken instead of R.array.surface_option1. Please help.

Answer 1

它实际上是一个 Java 问题, 不是和机器人 - 您不应该使用 < code> string 来比较 < code_ /code>, 使用 evols () 代替 < code>

if (acType != null && acType.equals("400G")){
    ...
}
else {
    ...
}

由于 strings 是对象, 比较引用,在等字符串中,这些引用很可能不同。

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