我有activity个EditTexts。如果用户点击“Cancel”按钮并且这些EditTexts中没有任何更改，那么该应用应该转到上一个活动，但如果这些EditTexts中的内容发生了变化，那么我希望用户请参阅AlertDialog：
Save changes you made?
NO YES
我为这些TextWatcher设置了EditTexts，如：
//let's set up a textwatcher so if the state of any of the edittexts has changed.
//if it has changed and user clicks 'CANCEL', we'll ask first, '
//You've made changes here. Sure you want to cancel?'
TextWatcher edittw = 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) {
Toast.makeText(EditContact.this, "change detected", Toast.LENGTH_SHORT).show();
}
};
categoryname.addTextChangedListener(edittw);
namename.addTextChangedListener(edittw);
phonename.addTextChangedListener(edittw);
addressname.addTextChangedListener(edittw);
commentname.addTextChangedListener(edittw);
AlertDialog按钮的Cancel - 无论是否有任何EditTexts出现，都会出现，但我只是希望它出现在EditTexts，否则应该没有AlerDialog，当前活动应该返回到之前的活动 - 如下所示：
private void cancelButton() {
cancel.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//add a dialogue box
AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());
builder.setMessage("Save changes you made?").setPositiveButton("Yes", dialogClickListener)
.setNegativeButton("No", dialogClickListener).show();
}
});
}
//Are you sure you want to cancel? dialogue
DialogInterface.OnClickListener dialogClickListener = new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
switch (which){
case DialogInterface.BUTTON_POSITIVE:
//Yes button clicked
pDialog = new ProgressDialog(EditContact.this);
// Showing progress dialog for the review being saved
pDialog.setMessage("Saving...");
pDialog.show();
//post the review_id in the current activity to EditContact.php and
StringRequest stringRequest = new StringRequest(Request.Method.POST, EditContact_URL,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
//hide the dialogue saying 'Saving...' when page is saved
pDialog.dismiss();
Toast.makeText(EditContact.this, response, Toast.LENGTH_LONG).show();
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(EditContact.this, "problem here", Toast.LENGTH_LONG).show();
}
}) {
@Override
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<String, String>();
//we are posting review_id into our EditContact.php file,
//the second value, review_id,
// is the value we get from Android.
// When we see this in our php, $_POST["review_id"],
//put in the value from Android
params.put("review_id", review_id);
return params;
}
};
AppController.getInstance().addToRequestQueue(stringRequest);
//when cancelled, back to the PopulistoListView class
Intent j = new Intent(EditContact.this,PopulistoListView.class);
startActivity(j);
break;
case DialogInterface.BUTTON_NEGATIVE:
//close the activity
finish();
}
}
};
我在互联网上搜索过有关“TextWatcher”和“AlertDialog”等短语的教程或帖子，但我找不到能帮助我实现我想要做的事情。
答案 0 :(得分：1)
尝试添加alertDialog，如下所示，您可以将对话框放在onAfterChange方法中：
TextWatcher edittw = 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) {
Toast.makeText(EditContact.this, "change detected", Toast.LENGTH_SHORT).show();
AlertDialog.Builder builder;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
builder = new AlertDialog.Builder(getApplicationContext(), android.R.style.Theme_Material_Dialog_Alert);
} else {
builder = new AlertDialog.Builder(getApplicationContext());
}
builder.setTitle("Delete entry")
.setMessage("Are you sure you want to delete this entry?")
.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
//You want yes
}
})
.setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
//You want no
}
})
.setIcon(android.R.drawable.ic_dialog_alert)
.show();
}
};
答案 1 :(得分：1)
创建boolean变量以跟踪textChange
boolean isDirty;
TextWatcher edittw = 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) {
Toast.makeText(EditContact.this, "change detected", Toast.LENGTH_SHORT).show();
isDirty = true;
}
};
categoryname.addTextChangedListener(edittw);
namename.addTextChangedListener(edittw);
phonename.addTextChangedListener(edittw);
addressname.addTextChangedListener(edittw);
commentname.addTextChangedListener(edittw);
并将取消按钮点击事件更改为此
private void cancelButton() {
cancel.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(isDirty) {
//add a dialogue box
AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());
builder.setMessage("Save changes you made?").setPositiveButton("Yes", dialogClickListener)
.setNegativeButton("No", dialogClickListener).show();
}
else {
// this will finish the current activity and the last activity will be popped from the stack.
finish();
}
}
});
}
答案 2 :(得分：1)
你只需使用类似的布尔变量
在类属性中声明检查变量
布尔检查;
在onTextChange()
true至TextWatcher
将cancelButton()更改为此
private void cancelButton() {
cancel.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(changed){
AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());
builder.setMessage("Save changes you made?").setPositiveButton("Yes", dialogClickListener)
.setNegativeButton("No", dialogClickListener).show();
}else {
Log.v(TAG,"nothing changed ");
}
}
});
}
答案 3 :(得分：0)
你可以做这样的事情
OrbitControls答案 4 :(得分：0)
在取消按钮onClick方法中，试试这个： -
@Override
onClick(View v) {
if(!(categoryname.getText().toString().isEmpty() && namename.getText().toString().isEmpty() && phonename.getText().toString().isEmpty() && addressname.getText().toString().isEmpty() && commentname.getText().toString().isEmpty())) {
// show your dialog
}
else {
// normal cancel
}
所有check the text中只有edittexts，如果其中任何一个不为空，则显示对话框.. !!
无需为上述问题添加
textChangeListener!!