mSearchEt = (EditText) findViewById(R.id.search_edit_text);

{
		mSearchEt.addTextChangedListener(new TextWatcher() {

			@Override
			public void onTextChanged(CharSequence s, int start, int before,
					int count) {
				// TODO Auto-generated method stub

			}

			@Override
			public void beforeTextChanged(CharSequence s, int start, int count,
					int after) {
				// TODO Auto-generated method stub

			}

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

		return;
	}
 

第三步：獲得EditText中的值：

String messages;=mSearchEt.getText().toString();

if (messages.length()<1){
                   utilsToast.showToastShort("請輸入關鍵字");//沒值


               }else{
                   utilsToast.showToastShort("傳送請求"+messages);
               }

採用if(editText.length()<1) 來判斷有無輸入