java - 单独的字符串输入android

Question

问题是我无法删除“，”，而只检查了一项，当有多个项目时，我不知道如何从最后删除“，”。
公共(public)类 CheckBox 扩展 AppCompatActivity 实现 View.OnClickListener {

ImageButton check_button;

CheckBox eminem , dre , tupac , royce , logic , big_sean;



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_e10_check_box);
    setTitle("Check Box");
    Inits();
}
private void Inits(){
    check_button = findViewById(R.id.check_button);

    eminem = findViewById(R.id.eminem);
    dre = findViewById(R.id.dre);
    tupac = findViewById(R.id.tupac);
    royce = findViewById(R.id.royca);
    logic = findViewById(R.id.logic);
    big_sean = findViewById(R.id.big_sean);

    check_button.setOnClickListener(this);
}

@Override
public void onClick(View view) {

    String result = "Your Favorite List : x";
    String singers = "";

    if(eminem.isChecked()){
        singers += "Eminem" + " , " ;
    }
    if (dre.isChecked()){
        singers += "Dr.Dre" + " , ";
    }
    if (tupac.isChecked()){
        singers += "Tupac" + " , ";
    }
    if (royce.isChecked()){
        singers += "Royce" + " , ";
    }
    if (logic.isChecked()){
        singers += "Logic" + " , ";
    }
    if (big_sean.isChecked()){
        singers += "Big Sean" + " , ";
    }
    app.t(result.replace("x" , singers));


}

}

Answer 1

您可以尝试使用 StringBuilder以获得更好的性能。附加到它时不会创建新对象。这是您的问题的可能解决方案:

        StringBuilder builder = new StringBuilder();
        if(eminem.isChecked()){
            builder.append("Eminem").append(RAPPER_SEPARATOR);
        }
        if (dre.isChecked()){
            builder.append("Dre").append(RAPPER_SEPARATOR);
        }
        if (tupac.isChecked()){
            builder.append("Tupac").append(RAPPER_SEPARATOR);
        }
        if (royce.isChecked()){
            builder.append("Royce").append(RAPPER_SEPARATOR);
        }
        if (logic.isChecked()){
            builder.append("Logic").append(RAPPER_SEPARATOR);
        }
        if (big_sean.isChecked()){
            builder.append("Big Sean").append(RAPPER_SEPARATOR);
        }
        final int length = builder.length();
        if (length > 0) {
            builder.delete(length - RAPPER_SEPARATOR.length() - 1, length - 1);
            app.t(result.replace("x" , builder.toString()));
        }

在哪里 RAPPER_SEPARATOR = " , " .
还要记住，代码有重复，如果 CheckBox文本与您要附加的文本相同，您可以创建一个像这样执行此操作的函数:

    private void appendRapperIfChecked(CheckBox cb, StringBuilder builder) {
        if (cb.isChecked()) {
            builder.append(cb.getText()).append(RAPPER_SEPARATOR);
        }
    }

并多次调用它:

        appendRapperIfChecked(builder, eminem);
        appendRapperIfChecked(builder, dre);
        appendRapperIfChecked(builder, tupac);
        appendRapperIfChecked(builder, royce);
        appendRapperIfChecked(builder, logic);
        appendRapperIfChecked(builder, big_sean);

        final int length = builder.length();
        if (length > 0) {
            builder.delete(length - RAPPER_SEPARATOR.length() - 1, length - 1);
            app.t(result.replace("x" , builder.toString()));
        }