如何处理 addTextChangedListener 和内存

Question

public class MainActivity extends AppCompatActivity {

EditText Percent, mmolGlic, mgGlic;

double mmol = 0, mg = 0, perc = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Percent = (EditText) findViewById(R.id.percent);
    mmolGlic = (EditText) findViewById(R.id.mmol_glic);
    mgGlic = (EditText) findViewById(R.id.mg_glic);



    /*mmolGlic.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            frommMol();
        }

        @Override
        public void afterTextChanged(Editable s) {

        }
    });*/

    Percent.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            fromPercent();
        }

        @Override
        public void afterTextChanged(Editable s) {

        }
    });

    /*mgGlic.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {

        }

        @Override
        public void afterTextChanged(Editable s) {
            frommg();
        }
    });*/
}

public void frommMol() {
    mmol = Double.parseDouble(mmolGlic.getText().toString());
    perc = (mmol/10.929) + 2.15;
    Percent.setText(String.format( "%.2f", perc ));
}

public void fromPercent(){
    perc = Double.parseDouble(Percent.getText().toString());
    mmol = (perc - 2.15) * 10.929;
    mmolGlic.setText(String.format( "%.2f", mmol ));
    mg = (perc*28.7) - 46.7;
    mgGlic.setText(String.format( "%.2f", mg ));
}

public void frommg(){
    mg = Double.parseDouble(mgGlic.getText().toString());
    perc = (mg + 46.7) / 28.7;
    Percent.setText(String.format( "%.2f", perc ));


}

}

大家早上好:)

这是一个连续的问题：Question 1

这是我正在尝试做的示例代码。但我有一些问题。我认为其中大部分是针对变量的逻辑以及如何处理更多 EditTexts 中的输入。例如：

1. 主要问题是我不能使用多个addTextChangedListener。我试图更好地解释：如果我将代码保留在这里，应用程序就会崩溃。我不确定，可能是因为我处理三个 EditText 的方式。
2. 然后我在删除文本时遇到问题：如果我有“5.99”并且我 按del，删除时会删除，直到5，然后 崩溃。可能我应该在文本字段为空时设置 变量 = 0。

你能帮帮我吗？非常感谢

Answer 1

public class MainActivity extends AppCompatActivity {

EditText Percent, mmolGlic, mgGlic;

double mmol = 0, mg = 0, perc = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Percent = (EditText) findViewById(R.id.percent);
    mmolGlic = (EditText) findViewById(R.id.mmol_glic);
    mgGlic = (EditText) findViewById(R.id.mg_glic);

 Percent.addTextChangedListener(percentWatcher);
        mmolGlic.addTextChangedListener(mmolGlicTextWatcher);
        mgGlic.addTextChangedListener(mgGlicWatcher);
}

 public void frommMol() {
        if (!mmolGlic.getText().toString().trim().isEmpty()) {
            mmol = Double.parseDouble(mmolGlic.getText().toString());
            perc = (mmol / 10.929) + 2.15;
            Percent.removeTextChangedListener(percentWatcher);
            Percent.setText(String.format("%.2f", perc));
            Percent.addTextChangedListener(percentWatcher);
        }
    }

    public void fromPercent() {
        if (!Percent.getText().toString().trim().isEmpty()) {
            perc = Double.parseDouble(Percent.getText().toString().trim());
            mmol = (perc - 2.15) * 10.929;
            mmolGlic.removeTextChangedListener(mmolGlicTextWatcher);
            mgGlic.removeTextChangedListener(mgGlicWatcher);
            mmolGlic.setText(String.format("%.2f", mmol));
            mg = (perc * 28.7) - 46.7;
            mgGlic.setText(String.format("%.2f", mg));
            mmolGlic.addTextChangedListener(mmolGlicTextWatcher);
            mgGlic.addTextChangedListener(mgGlicWatcher);
        }
    }

    public void frommg() {
        if (!mgGlic.getText().toString().trim().isEmpty()) {
            mg = Double.parseDouble(mgGlic.getText().toString());
            perc = (mg + 46.7) / 28.7;
            Percent.removeTextChangedListener(percentWatcher);
            Percent.setText(String.format("%.2f", perc));
            Percent.addTextChangedListener(percentWatcher);
        }
    }


    private TextWatcher percentWatcher = new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
            fromPercent();
        }

        @Override
        public void afterTextChanged(Editable editable) {

        }
    };

    private TextWatcher mgGlicWatcher = new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
            frommg();
        }

        @Override
        public void afterTextChanged(Editable editable) {

        }
    };

    private TextWatcher mmolGlicTextWatcher = new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
                frommMol();
        }

        @Override
        public void afterTextChanged(Editable editable) {

        }
    };

}


Hope this will help you.

Answer 2

好吧，即使您没有任何可使用的文本，您也正在执行您的操作。我建议您在执行 thefromPercent() 之前对 editTextView 进行空/空检查；手术。希望对您有所帮助。