我遇到了问题，我想点击列表，调用新活动并将按钮重命名为其他名称。
我尝试了几件事，没有任何效果，有人可以帮助我吗？
我的班级EditarTimes：
private AdapterView.OnItemClickListener selecionarTime = new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView arg0, View arg1, int pos, long id) {
t = times.get(pos);
CadastroTimes cad = new CadastroTimes();
CadastroTimes.salvar.setText("Alterar");
Intent intent = new Intent(EditarTimes.this, CadastroTimes.class);
startActivity(intent);
}
};
public class CadastroTimes extends AppCompatActivity {
private Time t;
private timeDatabase db;
private EditText edID;
private EditText edNome;
public Button salvar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_cadastro_times);
edID = (EditText) findViewById(R.id.edID);
edNome = (EditText) findViewById(R.id.edNome);
db = new timeDatabase(getApplicationContext());
salvar = (Button) findViewById(R.id.btnCadastrar);
salvar.setText("Cadastrar");
String newString;
if (savedInstanceState == null) {
Bundle extras = getIntent().getExtras();
if(extras == null) {
newString= null;
} else {
newString= extras.getString("Alterar");
}
} else {
newString= (String) savedInstanceState.getSerializable("Alterar");
}
//button in CadastroTimes activity to have that String as text
System.out.println(newString + " AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA");
salvar.setText(newString);
}
public void salvarTime(View v) {
t = new Time();
t.setNome(edNome.getText().toString());
if (salvar.getText().equals("Alterar")) {
db.atualizar(t);
exibirMensagem("Time atualizado com sucesso!");
} else {
db.salvar(t);
exibirMensagem("Time cadastrado com sucesso!");
}
Intent intent = new Intent(this, EditarTimes.class);
startActivity(intent);
}
private void limparDados() {
edID.setText("");
edNome.setText("");
edNome.requestFocus();
}
private void exibirMensagem(String msg) {
Toast.makeText(getApplicationContext(), msg, Toast.LENGTH_LONG).show();
}
}
public class EditarTimes extends AppCompatActivity {
private Time t;
private List times;
private timeDatabase db;
private ListView lvTimes;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_editar_times);
lvTimes = (ListView) findViewById(R.id.lvTimes);
lvTimes.setOnItemClickListener(selecionarTime);
lvTimes.setOnItemLongClickListener(excluirTime);
times = new ArrayList();
db = new timeDatabase(getApplicationContext());
atualizarLista();
}
private void excluirTime(final int idTime) {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Excluir time?")
.setIcon(android.R.drawable.ic_dialog_alert)
.setMessage("Deseja excluir esse time?")
.setCancelable(false)
.setPositiveButton(getString(R.string.sim),
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
if (db.deletar(idTime)) {
atualizarLista();
exibirMensagem(getString(R.string.msgExclusao));
} else {
exibirMensagem(getString(R.string.msgFalhaExclusao));
}
}
})
.setNegativeButton(getString(R.string.nao),
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
builder.create();
builder.show();
atualizarLista();
}
private void atualizarLista() {
times = db.listAll();
if (times != null) {
if (times.size() > 0) {
TimeListAdapter tla = new TimeListAdapter(
getApplicationContext(), times);
lvTimes.setAdapter(tla);
}
}
}
private AdapterView.OnItemClickListener selecionarTime = new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView arg0, View arg1, int pos, long id) {
t = times.get(pos);
Intent intent = new Intent(EditarTimes.this, CadastroTimes.class);
String strName = "Alterar";
intent.putExtra("Alterar", strName);
startActivity(intent);
//preecherDados(t);
}
};
private AdapterView.OnItemLongClickListener excluirTime = new AdapterView.OnItemLongClickListener() {
public boolean onItemLongClick(AdapterView arg0, View arg1,
int pos, long arg3) {
excluirTime(times.get(pos).getId());
return true;
}
};
/*private void preecherDados(Time time) {
edID.setText(String.valueOf(time.getId()));
edNome.setText(time.getNome());
}*/
private void exibirMensagem(String msg) {
Toast.makeText(getApplicationContext(), msg, Toast.LENGTH_LONG).show();
}
public void telaCadastrar(View view) {
Intent intent = new Intent(this, CadastroTimes.class);
startActivity(intent);
}
public void botaoSair(View view) {
Intent intent = new Intent(this, TelaInicial.class);
startActivity(intent);
}
}
答案 0 :(得分：9)
您可以将按钮标题传递给CadastroTimes，意图为
Intent intent = new Intent(EditarTimes.this, CadastroTimes.class);
intent.putExtra("buttontxt","Changed Text");
startActivity(intent);
然后在CadastroTimes.java中将按钮的文本设置为您传递的新值。代码如下：
button = (Button)findViewById(R.id.button); // This is your reference from the xml. button is my name, you might have your own id given already.
Bundle extras = getIntent().getExtras();
String value = ""; // You can do it in better and cleaner way
if (extras != null) {
value = extras.getString("buttontxt");
}
button.setText(value);
请务必在onCreate
setContentView内进行此操作
答案 1 :(得分：3)
//From Activity
Intent intent = new Intent(EditarTimes.this, CadastroTimes.class);
intent.pueExtra("change_tag", "text to change");
startActivity(intent)
//To Activity
public void onCreate(..){
Button changeButton = (Button)findViewById(R.id.your_button);
// Button to set received text
Intent intent = getIntent();
if(null != intent &&
!TextUtils.isEmpty(intent.getStringExtra("change_tag"))) {
String changeText = intent.getStringExtra("change_tag");
// Extracting sent text from intent
changeButton.setText(changeText);
// Setting received text on Button
}
}
对不起，我有点迟了。但是，我希望能帮到你。
答案 2 :(得分：1)
1：使用intent.putExtra()从一个活动另一个活动共享一个值，如：
在 ActivityOne.class ：
中Intent intent = new Intent(getApplicationContext(), ActivityTwo.class);
intent.putExtra("key", "value");
intent.startActivity();
在 ActivityTwo.class ：
中Intent intent = getIntent();
String var = intent.getStringExtra("key");
2：以编程方式修改按钮文本：
btn_object.setText(var);
希望这会对你有所帮助
答案 3 :(得分：0)
好的，所以第一步是选择你想要的按钮并将其作为公共静态对象（并将其放在类的顶部）。
public static Button button;
然后你可以在另一个类中使用它来操纵它：
ClassName.button.setText("My Button");
在你的情况下，它是
CadastroTimes.salvar.setText("Alterar");
答案 4 :(得分：0)
现在，我找到了你：
EditarTimes listview活动//set setOnItemClickListener
youtListView.setOnItemClickListener(new android.widget.AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,int position, long id) {
Intent i = new Intent(EditarTimes.this, CadastroTimes.class);
//text which you want to display on the button to CadastroTimes activity
String strName = "hello button";
i.putExtra("STRING_I_NEED", strName);
}
});
：
CadastroTimes在onCreate()活动中，
在String newString;
if (savedInstanceState == null) {
Bundle extras = getIntent().getExtras();
if(extras == null) {
newString= null;
} else {
newString= extras.getString("STRING_I_NEED");
}
} else {
newString= (String) savedInstanceState.getSerializable("STRING_I_NEED");
}
方法下，获取文本字符串： -
{{_id}}//按钮将该String作为文本 yourButton.setText（newString）;
答案 5 :(得分：0)
更改按钮文字：
答案 6 :(得分：0)
如果您要从中更改值，请不要通过意图进行操作，您可以使用文件将值保存到文件中，或者您具有多个值，请使用数据库和访问权限 值oncreate设置文本的值。...
答案 7 :(得分：0)
在我的情况下，我必须从样式为EditText的{{1}}发送一个Dialog值，然后从Activity中检索该值。 与上面的某些答案类似，也是可行的。
TimerActivity.class
Service
然后在Service类中检索值，并在public void buttonClick_timerOK(View view) {
// Identify the (EditText) for reference:
EditText editText_timerValue;
editText_timerValue = (EditText) findViewById(R.id.et_timerValue);
// Required 'if' statement (to avoid NullPointerException):
if (editText_timerValue != null) {
// Continue with Button code..
// Convert value of the (EditText) to a (String)
String string_timerValue;
string_timerValue = editText_timerValue.getText().toString();
// Declare Intent for starting the Service
Intent intent = new Intent(this, TimerService.class);
// Add Intent-Extras as data from (EditText)
intent.putExtra("TIMER_VALUE", string_timerValue);
// Start Service
startService(intent);
// Close current Activity
finish();
} else {
Toast.makeText(TimerActivity.this, "Please enter a Value!", Toast.LENGTH_LONG).show();
}
}
中使用它。
TimerService.class
onStartCommand
希望我的贡献能有所帮助！
祝您编程愉快！
答案 8 :(得分：0)
访问另一个活动的视图引用是一种不道德的行为。因为无法保证在您访问参考文献时参考文献仍然存在（考虑null参考风险）。
您需要做的是使其他Activity从数据源（例如，持久性存储或共享首选项）读取值（要显示），而另一个Activity处理这些值。因此，看起来好像它在更改另一个活动的值，但实际上它是从数据源获取值。
答案 9 :(得分：0)
使用 SharedPreferences：
注意：SharedPreferences 会在您关闭应用后保存数据，但删除后会丢失。
在 EditarTimes.java 中：
private AdapterView.OnItemClickListener selecionarTime = new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView arg0, View arg1, int pos, long id) {
t = times.get(pos);
SharedPreferences.Editor editor = getSharedPreferences("DATA", MODE_PRIVATE).edit();
editor.putString("btnText", "Your desired text");
editor.apply();
Intent intent = new Intent(EditarTimes.this, CadastroTimes.class);
startActivity(intent);
}
};
在 CadastroTimes.java 中
public Button salvar;
salvar.setText(getSharedPreferences("DATA", MODE_PRIVATE).getString("btnText", ""));
//note that default value should be blank