从 TextView 获取值 [重复]

Question

我上网查过了，但没有找到从textview获取这个值的方法

错误是：无法解析方法ValueOf()

time_left = timeLeftNumber.valueOf() - 1;

.

    package com.example.sensational.timetopress;

import android.os.CountDownTimer;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.TextView;


public class press_screen extends ActionBarActivity {

    private int time_left;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_press_screen);

    }

    //Create Timer


    CountDownTimer timer = new CountDownTimer(30000, 1000) {
        @Override
        public void onTick(long millisUntilFinished) {
            TextView amountOfTaps = (TextView) findViewById(R.id.amount_of_taps);
            TextView timeLeftNumber = (TextView) findViewById(R.id.time_left_number_tv);
            time_left = timeLeftNumber.valueOf() - 1;
            timeLeftNumber.setText();
        }

        @Override
        public void onFinish() {

        }
    };

Answer 1

TextView 没有 valueOf() 方法。您可以进行以下操作：

    TextView amountOfTaps = (TextView) findViewById(R.id.amount_of_taps);
    TextView timeLeftNumber = (TextView) findViewById(R.id.time_left_number_tv);
    time_left = Integer.valueOf(timeLeftNumber.getText().toString()) - 1;
    timeLeftNumber.setText();

Answer 2

你需要做的：

time_left = Integer.parseInt(timeLeftNumber.getText().toString()) - 1;

Answer 3

要从TextView 获取价值，您应该使用getText() 方法。它返回CharSequence，可能很容易更改为String，然后您必须像这样将获得的值转换为int

time_left = Integer.parseInt(timeLeftNumber.getText().toString()

如果输入的文本不是数字，此方法可能会抛出 NumberFormatException，因此您应该将此调用放在 try-catch 块中。

Answer 4

只需使用返回CharSequence的方法getText()：

time_left = timeLeftNumber.getText().toString();

为了获得Integer 值使用

time_left = parseInt(timeLeftNumber.getText().toString(), 10) -1;

因为它可能会抛出 NumberFormatException（最终版本）：

try {
    time_left = parseInt(timeLeftNumber.getText().toString(), 10) -1;

} catch (NumberFormatException e) {
    // handle invalid numbers; set reasonable default value
    time_left = 0;
}