Android 无法在first edittext字段上设置焦点？

我无法将焦点设置在first edittext字段（除下面的3个字段外）。代码为：

k1_e=(EditText)findViewById(R.id.k1_editText);
k1_e.requestFocusFromTouch();
try{
k1=Float.parseFloat(k1_e.getText().toString());
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}
k2_e=(EditText)findViewById(R.id.k2_editText);
try{
    k2=Float.parseFloat(k2_e.getText().toString());
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}
al_e=(EditText)findViewById(R.id.al_editText);
try{
    al=Float.parseFloat(al_e.getText().toString());
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}
alconst_e=(EditText)findViewById(R.id.al_const_editText);
try{
    al_const=Float.parseFloat(alconst_e.getText().toString()); 
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}

12-29 08:10:05.241: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""
12-29 08:10:05.261: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""
12-29 08:10:05.261: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""
12-29 08:10:05.271: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""

int flag = 0;

  getView()
{
if(flag == 0)
{
k1_e.requestFocusFromTouch();flag = 1;
}
  string abc = k1_e.getText().toString()
        if(abc != null && !abc.equals(""))
        {
         k1=Float.parseFloat(k1_e.getText().toString());
        }
    else
    {
      k1 = 0.0;
    }

}

---

当应用程序在emulator上执行时，它会自动将焦点设置为last edittext字段，并引发异常：

k1_e=(EditText)findViewById(R.id.k1_editText);
k1_e.requestFocusFromTouch();
try{
k1=Float.parseFloat(k1_e.getText().toString());
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}
k2_e=(EditText)findViewById(R.id.k2_editText);
try{
    k2=Float.parseFloat(k2_e.getText().toString());
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}
al_e=(EditText)findViewById(R.id.al_editText);
try{
    al=Float.parseFloat(al_e.getText().toString());
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}
alconst_e=(EditText)findViewById(R.id.al_const_editText);
try{
    al_const=Float.parseFloat(alconst_e.getText().toString()); 
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}

12-29 08:10:05.241: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""
12-29 08:10:05.261: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""
12-29 08:10:05.261: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""
12-29 08:10:05.271: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""

int flag = 0;

  getView()
{
if(flag == 0)
{
k1_e.requestFocusFromTouch();flag = 1;
}
  string abc = k1_e.getText().toString()
        if(abc != null && !abc.equals(""))
        {
         k1=Float.parseFloat(k1_e.getText().toString());
        }
    else
    {
      k1 = 0.0;
    }

}

---

错误是什么。我是初学者。请帮助

您的k1_e.getText（）。toString（）返回的

字符串不能转换为浮点值

所有人都试试这个：

k1_e=(EditText)findViewById(R.id.k1_editText);
k1_e.requestFocusFromTouch();
try{
k1=Float.parseFloat(k1_e.getText().toString());
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}
k2_e=(EditText)findViewById(R.id.k2_editText);
try{
    k2=Float.parseFloat(k2_e.getText().toString());
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}
al_e=(EditText)findViewById(R.id.al_editText);
try{
    al=Float.parseFloat(al_e.getText().toString());
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}
alconst_e=(EditText)findViewById(R.id.al_const_editText);
try{
    al_const=Float.parseFloat(alconst_e.getText().toString()); 
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}

12-29 08:10:05.241: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""
12-29 08:10:05.261: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""
12-29 08:10:05.261: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""
12-29 08:10:05.271: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""

int flag = 0;

  getView()
{
if(flag == 0)
{
k1_e.requestFocusFromTouch();flag = 1;
}
  string abc = k1_e.getText().toString()
        if(abc != null && !abc.equals(""))
        {
         k1=Float.parseFloat(k1_e.getText().toString());
        }
    else
    {
      k1 = 0.0;
    }

}

做这个，做个
int标志=0gobal到您的班级。
当您第一次执行getview时，将标志设为1

像这样：

k1_e=(EditText)findViewById(R.id.k1_editText);
k1_e.requestFocusFromTouch();
try{
k1=Float.parseFloat(k1_e.getText().toString());
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}
k2_e=(EditText)findViewById(R.id.k2_editText);
try{
    k2=Float.parseFloat(k2_e.getText().toString());
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}
al_e=(EditText)findViewById(R.id.al_editText);
try{
    al=Float.parseFloat(al_e.getText().toString());
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}
alconst_e=(EditText)findViewById(R.id.al_const_editText);
try{
    al_const=Float.parseFloat(alconst_e.getText().toString()); 
}catch(Exception e) {
    Log.e("logtag", "Exception: " + e.toString());
}

12-29 08:10:05.241: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""
12-29 08:10:05.261: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""
12-29 08:10:05.261: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""
12-29 08:10:05.271: E/logtag(769): Exception: java.lang.NumberFormatException: Invalid float: ""

int flag = 0;

  getView()
{
if(flag == 0)
{
k1_e.requestFocusFromTouch();flag = 1;
}
  string abc = k1_e.getText().toString()
        if(abc != null && !abc.equals(""))
        {
         k1=Float.parseFloat(k1_e.getText().toString());
        }
    else
    {
      k1 = 0.0;
    }

}

k1_e.getText（）.toString（）返回“”无法转换为Floatedittext.requestFocus（）；按程序写这个。。为什么要使用touchfocus..问题是“abc”将为空，因为我无法在k1文本框上获得焦点。你能帮我吗？你在用k1_e.requestFocusFromTouch（）吗；在您的自定义视图中？？现在我可以向k1输入数据，但字段没有聚焦。你的意思是如果（flag==0）{k1_e.requestFocusFromTouch（）；flag=1；}代码没有正确执行请使用requestFocus（）而不是requestFocusFromTouch（），然后告诉我